ABM Week 7 Edition | Schedule

Abstract:

Iron and steelmaking industry are the main emitters of greenhouse gases. To improve the parameters of fuel consumption and CO2 emission in the TR, the pre-reduction of the iron-bearing materials is an alternative. Firstly, this study aimed to evaluate, through CFD simulations, the impact of using metallic charge with different metallization degrees. Following, the pre-reduction of briquettes using the Tecnored Recycler off-gas was evaluated. The simulation results showed that the use of this gas in pre-reduction processes can be a promising way to reduce fuel consumption and CO2 emissions during the hot metal production in TR. In addition, the use of pre-reduced charge improves the reducing potential of the TR off-gas, bringing advantages to the use of this gas in pre-reduction processes. Preliminary tests showed that a synthetic gaseous mixture simulating TR off-gas has the ability to metallize self-reducing and iron ore briquettes. However, it is necessary to evaluate different gaseous mixtures to define the best pre-reduction condition to obtain metallization degrees that bring relevant advantages for the TR furnace operation.

Abstract:

The development of microstructural analysis methods, mainly non-destructive ones, for the evaluation of mechanical, physical and chemical properties becomes fundamental as the demand for new materials grows. The aim of this work is to correlate the microstructural evolution with the electrical conductivity of interstitial free steel (IF) samples during recovery, partial to complete recrystallization, until grain growth. For this, previously developed software was used, which, by means of data acquisition and processing using a four-point probe, relates the electrical conductivity and the microstructure of the material. In order to verify the efficiency of the software, the preparation, metallographic analysis, and measurement of the electrical conductivity of five IF steel samples with different manufacturing procedures were performed: one sample 85% rolled (AL) and four samples heat treated at 950 °C with duration times of 150 seconds, 10, 30, and 60 minutes. The results obtained with the optical microscope revealed microstructures with deformed grains for the rolled sample, and for the samples submitted to heat treatment, they revealed equiaxial grains. The analysis of the conductivity of the samples made by the software confirmed that these values are as expected, showing its effectiveness.

Abstract:

Dredging is employed in ports to maintain depth in shipping channels. However, a high amount of this dredged sediment needs to be disposed of in duly licensed dump areas. A solution for this material with the vision of reuse and circular economy is to be used as a precursor for alkali-activated material (MMA), and to have application in civil construction. Thus, the objective of this work was to analyze the potential of waste from Porto do Açu (RPA) from the dredging process as MAA. Therefore, the RPA was activated in a “natural” state and calcined at 650 ºC and 850 ºC. Its activation potential was characterized via isothermal conduction calorimetry in a fresh state and its compressive strength in a hardened state. X-ray fluorescence (FRX) showed that RPA can be considered a precursor with a high content of aluminosilicate and low calcium. Regarding calorimetry, the paste with RPA in natura showed a low heat flux. The strength values were 10.26 and 10.93 MPa for 650 and 850 ºC, respectively. This indicates that the temperature of 650 ºC becomes more convenient to reach a reasonable mechanical performance in the civil construction industry.

Abstract:

This paper describes a cooperative project developed by Aperam South America (ASA) and Companhia Brasileira de Metalurgia e Mineração (CBMM) with the aim of partly replacing manganese with small concentrations of niobium in structural low carbon steels, like SAE/AISI 1012. The results got in the final product after Steckel rolling and delivery to partner customers showed the following advantages: potential cost reduction and improvement in microstructural refinement, homogeneity, and inclusionary cleanness, while keeping the same level of mechanical properties. This project allows ASA to include in its product mix an alloy that innovates the design for structural steels. Besides that, this alloy broke ground for the replication of this concept in other structural steels.

Abstract:

Mechanical tests are widely used in the metallurgical industry, mainly to analyze the formability of materials. Among these procedures, the hole expansion test permits the assessment of the performance of metal sheets in stretching operations. The flow behavior of the material in this test can be studied in detail through numerical simulations, overcoming empirical limitations. The current investigation was therefore initiated to examine the strain distributions along tangential plane of the sheets subjected to testing through hole expansion. The study also aimed to predict the axial loads required for punch displacement and the hole expansion index in a DP600 dual-phase steel. Variations in three parameters (thickness, friction, and hole diameter) were proposed using two different punch geometries: conical and cylindrical. The results showed a great influence of the punch geometry adopted, together with the thickness and hole diameter, with the effect of friction being less pronounced in all cases.

Abstract:

Advanced High Strength Steels (AHSS) have been applied in the manufacturing of automotive parts. These steels grades have a combination of a ferritic matrix, with high ductility; and a second constituent dispersed in the matrix (which can be martensite, bainite or a combination of both), which presents high hardness, making them more sensitive to edge damage. Defects such as nucleation and crack propagation from the cut edges may occur. Therefore, the objective of this research is to design, manufacture and test a experimental bench in order to evaluate cryogenic punching of the cold rolled DP780 steel sheet, with a thickness of 0.65 mm. Punching cutting at cryogenic temperatures is seen as an alternative for reducing the level of work hardening in the material, having the potential to produce parts with better cutting quality, as well as greater flange stretching capacity. The present study provided the development of a device for application of liquid nitrogen (LN2) on the sample, with the temperature control, and evaluated the work hardening distribution, using the EBSD technique, along the cut edges at ambient and cryogenic temperatures.

Abstract:

In the continuous casting machine, tundish is a reservoir and a distributor for liquid steel from the ladle into the molds. It is important to investigate the influence of covering powder composition on the tundish stopper rod corrosion, i.e., at the slag line. Therefore, the objective of this work is to investigate the thermodynamic properties of a Ca-aluminate covering powder, through simulations using computational thermodynamics as a tool. Using computational thermodynamics, conclusions are obtained on the behavior of the covering powder during the industrial process since there are information on nature, amount, and composition of the phases at steelmaking temperatures. It was concluded that an easy-to-implement solution, in the industrial context, could be implemented to reduce corrosion of the stopper rod caused by covering powder.

Abstract:

With the evolution of the steel grades that demands specific applications and high-quality requirements, grades with low sulfur content have had an expressive increasingly demand. Based on these facts, this work aims to evaluate the properties and characteristics of the slag formed in the steel desulfurization step in the ladle, after the steel tapping from converter to ladle, for a steel grade with a target sulfur content (S) of 30ppm, and relate them to the efficiency of desulfurization, which measures the ability to remove sulfur. The evaluation of the slag properties was performed with the aid of a computational thermodynamics’ software, for a better understanding of the phenomena that occur at the metal-slag interfaces in the steel refining process, as well as in the evaluation of important properties for these processes. The Steel Desulfurization Factor (SFDeS) parameter developed by Pezzin [1] was adapted for the case where some slags do not have a solid CaO fraction. The results confirmed that the most efficient slags for steel desulfurization are those with an optimal solid CaO content and that the Desulfurization Factor can be used to evaluate and predict the desulfurization efficiency for the studied slags.

Abstract:

Coke oven battery maintenance is a recurring operation due to the rigors of day-to-day operations. However, when minor repairs to individual walls are required, hot repairs can be made with temporary shutdown of this furnace in question. If the efficiency of the furnaces is less than 70% or if more than 50% of the furnaces need to be repaired with production losses, it is more interesting from an economic point of view to cooling down the entire battery and perform programmed and optimized maintenance. This is because it is very difficult to bring the battery back to its original form of productivity by occasional hot repairs. A battery operating at less than 70% of its rated capacity will lose one month of total production every 3.5 months. Therefore, make the maintenance with the cooled battery can solve numerous problems that have developed over time all at once, drastically reducing repair time and resume battery as early as possible. In this work, techniques for cooling the entire battery while maintaining its integrity are presented. Numerical simulations were performed using FLUENT /ANSYS for flow analysis and KFCSIM developed and validated by AESTUS for transient heat transfer.

Abstract:

Through laboratory scale grinding tests, with the methodology of predicting energy requirement and physical and mineralogical characterizations of different ores used in Vale's pelletizing production process, it was possible to obtain magnitudes such as grinding efficiency in terms of specific surface generation (BSA) and energy consumption. Such results allow the prediction of ore behavior on an industrial scale, especially with the addition of industrial process data, obtaining a linear regression model whose response, the average productivity per mill, showed great adherence to real values. It was possible to associate and prove the effect of the presence of hydrated and porous minerals on an increase in milling productivity, as well as the effect of increasing the cyclone pressure in a closed circuit. The quantitative knowledge of these effects allows the analysis of the capacity of the installed circuit and also the use of the best possible configurations in view of the characteristics of the fed ore

Abstract:

Systems simulation is a tool to support and support the planning and decision-making processes increasingly used in the mining industry. This study will address the methodology and steps of a simulation project. In addition, some real cases will be presented in different application areas such as: mine, plant, logistics and port, through dynamic simulation models that delivered significant results by assisting in decision making, identifying the bottlenecks and the investiments and quantity of resources required

Abstract:

Adopting advanced process control strategies is crucial to maximize the financial return of mineral processing facilities. This approach was applied in the Classification step with hydrocyclones of an iron ore plant, combining three typical control structures: intelligent automatism of hydrocyclones automatic valve, multi-loop regulatory control strategy and fuzzy expert system to control the density set point in classification. This set of applications resulted in greater stability due to the greater adherence of the pressure of the hydrocyclones in the optimal operating ranges, allowing for a potential increase of about 5% in the mass destined for the flotation circuit to produce direct reduction pellet feed.

Abstract:

The blast furnace is the most used route for iron and steelmaking production due to the numerous advantages it presents. However, this process requires a high energy consumption, in addition to emitting large amounts of CO2 and other pollutants in the atmosphere. In this context, the refractory industry plays an important role in the decarbonization process through the implementation of safe, integrated, and innovative solutions that allow customers to reduce their CO2 footprint without compromising the performance of their operations. This paper aims to present the latest advances in refractory technologies and blast furnace runners maintenance practices and to share some of the outstanding results achieved by using digital integrated solutions, as well as their impact in the performance, safety, and process stability

Abstract:

The continuous casting process is currently the most important for the solidification of steels worldwide. In slab continuous casting machines (CCM), the drive rollers are usually made of forged steel, and the EN 42CrMo4 alloy is very commonly used for manufacturing. However, despite having good malleability and resistance to withstand operating conditions involving vibrations and mechanical stresses, this material is not suitable to withstand severe wear conditions under high temperatures. These situations are commonly observed, as the rollers come into direct contact with the solidified plate, whose temperature can be higher than 1000 ºC. Thus, to minimize the wear caused by friction, it is common to cover these rollers with more wear-resistant steels through welding processes. For this application, the use of martensitic ferritic steels is very common. The objective of this work was to study the microstructure formed and the hardness profiles of two rolls submitted to the coating process by welding (Submerged Arc Welding). For the present study, two ferritic martensitic stainless steels were evaluated. The first conventional alloy DIN 8555 class UP 5-GF-45-C, containing higher Ni and low Cr, the second steel DIN EN 14700 class T Fe 8 containing higher Mo and low Ni. Specimens were prepared and the hardness profile was measured as well as the microstructural characteristics. The results show that the hardness profile decreases as we approach the base material, however with distinct gradients, where the DIN EN 14700 standard presents a superior average difference of 175 Vickers HV0.5 and martensitic structures with similarity between the materials.

Abstract:

In order to mitigate environmental impacts, it was recently proposed the utilization of biocarbon briquettes with the goal to partially replace the natural gas in pellet indurating process. The addiction of briquettes over the pellet bed, despite representing environmental benefits, represents a challenge as the material is susceptible to mechanical degradation, which may suffer loss of its integrity e the generation of fragments in handling operations, that can reduce the porosity of the pellet bed and reduce the efficiency of the pellet indurating in the furnace. The current work deals with the mechanical characterization of breaking properties of three charcoal briquettes samples using an experimental methodology and mathematical models. The approach comprises mechanical degradation to determine the superficial breakage rates when the briquettes are subjected to shear stress conditions. The results show that is possible do differentiate the behavior of the studied briquettes according to their genesis, allowing the subsequent application of degradation prediction models utilizing the UFRJ methodology to model particle breakage.

Abstract:

A new set of creep test results were added to a previously obtained database, now making a total of 85 creep data and 25 hot tensile data on 2.25Cr1Mo steel. The constant load creep tests were carried out in the range of 500oC to 700oC, with stresses varying from 24,1 to 483 MPa. The hot tensile data were obtained in the same temperature range, with strain rates varying from 6,67x10-6 to 1,33x10-2 s-1 and were transposed to the creep condition using a criterion of equivalence proposed for the two types of test. The data were all plotted in the form Log(έmin)xLog(S/E) and could be rationalized by a single curve in the form Log(Z)xLog(S/E) with Qc≈437 kJ/mol exhibiting 3 regions of different strain mechanisms with n≈2,2 in the low stress region, n≈7,0 in the intermediate region and n≈49,5 in the high stress region. The data could be expressed by the Monkman-Grant relationship as έmin.tr=0,052. The present results show excellent agreement when compared to works from other internationally renowned laboratories.

Abstract:

Due to modern advances in the area of polymeric composites matrix reinforced by vegetable natural fibers, increasing demand for technologies that contribute as a potential for expansion and optimization, both the structural point of view, environmental, sustainable and the sectors of renewable energy, it is necessary studies that prioritize an approach precisely in the intersection of all these scientific and technological contemporary challenges. The development of this research fulfills a first experimental stage of a relevant academic research nowadays, which consists of evaluating the potential of application of a epoxy matrix composite reinforced by ramie fibers fabric in the wind sector, such proposed experimental design aims to obtain an average value for the density of natural fibers in question in the acquired fabric and by occasional necessity, the adequacy of the pycnometers to what prescribes relevant standards to the tests. Therefore, a statistical validation was sought, even for these glass instruments, considering that it cannot be considered, at first, the hypothesis that they would be in identical conditions of use. Thus, the experimental methodology consisted in the design of four treatments or groups representing each of the four pycnometers available. After performing the tests and obtaining the pertinent measurements, an one-way ANOVA demonstrated the statistical non significance among the mathematical differences presented by the density means of the ramie fibers that form the fabric, thus evidencing a validation regarding the equivalence of use for the glass instruments employed and, consequently, a general mean could be calculated assuming all forty measurements obtained in the laboratory. Finally, a comparison of this general mean with specific literature values showed excellent similarity among both, fact that provides reliable data to the continuity of a whole research that intend to combine a composite material with better biodegradability than the synthetics, sustainability and reduction carbon emissions which intensify the greenhouse effect

Abstract:

The field of civil engineering is a market that is increasingly progressing associated with the development of the country. Steel, one of the main materials used in this field, has been evolving to keep pace with this development. In order for this important ferrous material to remain competitive, steelmakers are looking for a microstructural evolution to meet the mechanical properties of the materials needed today. This microstructural change is related to heat treatments involving phase transformations in the material, but also effects that will occur along natural processes in different materials. This paper presents an evolution in the elastic relationship property of the Ribbed Wire CA60 AM60B from the recovery of stock.

Abstract:

The simulation of steel hot rolling processes is gaining more and more importance, since well-fitted models allow accelerating and reducing the costs associated with the development of new products, the optimization of thermomechanical processing and increase of the mechanical homogeneity of the final products, within the rolled product and from product to product. A great deal of work in this direction has been carried out for more than ten years by CEIT, sponsored by CBMM, initially with the development of MicroSim®, which calculates the evolution of the distribution of austenitic grain size during the hot rolling process of structural steels, microalloyed or not. This is a work in progress, towards the calculation of the mechanical properties of the final product, now with the development of MicroSim – Phase Transformation (PhasTranSim®), an intermediate model for calculating austenite transformation and characteristics of the ferritic-pearlitic microstructure of the final product, which will be described in this work.

Abstract:

Roughing mill (RM) is the initial stage of deformation on the Hot Strip Mill (HSM), which is responsible for ensuring the transfer bar's dimensional, shape, and flatness accuracy. An adequate RM pass schedule, which comprises the initial rolling conditions of biting and rolling speeds, horizontal and vertical roll gaps, and other critical parameters, is vital for process stability and usually is controlled by a mathematical model, as is the case of Usiminas Ipatinga HSM. However, controlling the material front-end curvature during the RM stage is challenging due to the numerous influences that affect curvature in each deformation step. In this sense, this study demonstrates the development of an analytical tool for predicting curvature radius, with the shape factor as the key parameter for analyzing the geometric influences on curvature formation. The proposed tool considers the effect of the main process parameters that cause curvature, such as the entry angle of the material, the sensitivity of work rolls peripheral speeds, the friction differences between upper and lower rolls, and the temperature differences between the upper and lower material surfaces. The study presents the mechanisms involved in developing the proposed tool and the results of applying the adjustments to the setup model of the rolling mills. The results demonstrate a considerable improvement in the occurrence of front-end curvature during rolling, indicating the effectiveness of the proposed approach, as well as the possibility of further process optimizations.

Abstract:

The need to become more competitive has led steel industries to study ways to optimize process times, aiming to increase their production capacity. One of the main parameters evaluated in steelmaking worldwide is tap-to-tap time, which is directly correlated to productivity indexes. Preparation time for tapping is one step in tap-to-tap procedure and consists in the time spent between the end of blowing and the beginning of steel tapping. Therefore, this study's main objective was to reduce the preparation time for tapping of the converters at SteelMaking 2 at Usiminas plant. The main parameters that affect this phase of the process were mapped and actions were taken to mitigate delays. There was a reduction of 1.85 minutes in the preparation time for tapping after implemented actions without compromising the chemical composition. The obtained results of this practice provided significant productivity gains and optimization of process times.

Abstract:

In this paper will be presented the improvement of operational and quality performance in slabs of low carbon Al and Si alloyed for electrical applications. Using the process variables controlling and statistical tools, it was possible to identify a specific steel into the low carbon steel grades which presented high breakout alarms index when compared to conventional low carbon grades. In addition, these alarms caused downgrades in some slabs and eventually heat sequence interruption. Analyzing the steel chemical composition and the flux chemical composition modification during the casting, by sampling the liquid mold flux, it was possible to identify the reason of operational and quality problems, that is related to Al2O3 mold flux pick up, that leads to viscosity increase and deficient lubrication. A specific mold flux was suggested and tested to maintain the lubrication capacity even with high Al2O3 mold flux pick up. It was possible to measure the improvement using the breakout alarms index and the friction in the mold. Both variables presented significative improvement, which lead to better quality and operational results.

Abstract:

The objective of this project was the implementation of new automatic deskulling system in the steel works at CSN – Companhia Siderírgica Nacional to optimize the availability of RH vessels with greater safety for assembly and use. The new implementation replaces the manual deskulling model with the automatic system using the TOP lance and vacuum system in joint operation, aiming at the lowest environmental impact without the outflow of red smoke by snorkels during the burning of the skull inside the vessel. The automatic deskulling solution using only oxygen remains the best safety, equipment availability and operational cost approach to this vacuum technology in the single RH at meltshop plant. The main aspects of lance project and vacuum operation are described in this document. The RH vacuum degassing is responsible for improving metallurgical performances, especially in terms of nitrogen, hydrogen removal and steel purity level. For this, it's necessary to always ensure a cleaner vessel for a perfect exchange of refractory coating with more safety and quality. The downstream process and results are strictly linked to RH vacuum degasser performance. The metallurgical performances and life performance of RH vacuum degassing vessels are analyzed and commented in this work.

Abstract:

Superduplex stainless steels are applied in oil and gas industry because of their resistance associated with their bi-phasic microstructure of ferrite and austenite. In the micromachining of this steel, cutting geometry is of the same magnitude of the workpiece grains and this can influence on the cutting dynamics during the tooth engagement one time through a ductile phase and another time through a fragile phase, causing variations on the cutting forces and surface integrity. Workpiece integrity was analyzed by measuring roughness and top-burr formed on the side of the machined grooves. Tool wear was evaluated by the increase of the point radius and the variation of the specific cutting force with cutting time. It is possible to observe also an increase on the average roughness and a decrease of the top-burr for lower feed values..

Abstract:

The quality of the metallurgical coke is essential for a better performance in the Blast Furnace (acting as a fuel, reducing agent and permeable support), in addition to provide stability for the operation. In this way, several methods and models of quality prediction are being developed to assist in the production of coke with the desired quality. One of the tools available for this previsions are the pilot coke ovens. It is possible to evaluate the performance of the coal blend and simulate coke production, correlating data from the pilot production and industrial production to create models of coke quality prediction (DI and CSR). Therefore, the objective of the study was to evaluate the use of coals and coal blend in the coking process, as well to compare the quality of the coke obtained in pilot scale with the results in industrial scale. The tests in the pilot oven provided satisfactory results, allowing to evaluate the coals, blending performance, and to obtain results of DI and CSR to predict the coke quality.

Abstract:

Iron ore pellets are produced using a matrix of fuel, whether solid, liquid or gaseous. This thermic energy is necessary to transform fine iron ore into a high value agglomerate (pellets), for direct reduction reactors and blast furnaces. In the search renewable fuels to reduce greenhouse gases there’s the charcoal, a product of high calorific value, produced through the pyrolysis process of wood in charcoal furnaces. To be renewable, charcoal must come from planted forests, whose main input is eucalyptus. Charcoal was tested on a pilot scale, as a complementary fuel to anthracite, for the production of iron ore pellets. Chemical, physical and granulometric analyzes of a coal were carried out, in addiction to its grinding to pelletizing process size adapt. Pelletizing, green ball formation and burning tests were also carried out to assess its potential for use. The material showed satisfactory as a complementary fuel in all parameters evaluated. Thus, charcoal proved to be an efficient and sustainable alternative for use in the pellet solid fuel matrix

Abstract:

DEM is a useful tool for simulating flow of granular material such as minerals. In these simulations particles are often represented by spheres or clusters of spheres with the aim of reducing the computational effort. However, mineral particles present highly irregular shapes, which may be better represented by polyhedral. Fortunately, software such as Rocky already allow use of 3D models in “.stl” format as particle geometry. The aim of this work is to develop 3D models of particles according to their distributions in groups defined by their aspect ratios, that then can be utilized as input to DEM simulation of any ore. Starting with the characterization of two rocks (itabirite and granulite) the cumulative distributions of aspect ratios were calculated. Particles were then divided in groups according to those aspect ratios, with representative particles modeled in CAD. In order to demonstrate the relevance of shape, the angle of repose test was simulated of the studied materials.

Abstract:

Desliming, carried out in hydrocyclones, is one of the component operations of the itabirite iron ore processing circuit at the industrial unit of Anglo American, MG. Its performance is commonly analyzed in terms of parameters such as corrected cut size and partition, which in turn are basically dependent on the characteristics of the feed and the operating conditions applied. The objective of this work was to develop a mathematical model adjustment to simulate the performance of hydrocyclones in the desliming of itabirite iron ore in an industrial unit. For that, several samplings were carried out in the hydrocyclones of the circuit, followed by analyzes of operational stability, mass balance, adjustment of the calibration parameters of the Nageswarararo model, simulations and validation, using the IES software. It was concluded that it is possible to predict the corrected cut size, water partition and operational pressure for hydrocyclones in the desliming of itabirite iron ore, using the Nageswararao model, in the IES software. The mean of the measured and simulated data did not show statistical difference, with 95% confidence, by the Students t-test

Abstract:

At the heart of the steel industry are the blast furnaces, responsible for the reduction of iron ore into pig iron. The availability of the trough and runners is a crucial parameter for the operation of the casting house, interfering in its productivity and operational safety. Blast furnaces that have two tap holes suffer from loss of productivity during the repair period of T&R due to consecutive operation in only one tap hole, representing a loss of 10% of the nominal capacity of the blast furnace. Ternium Brasil, seeking performance and sustainability, sought a partnership with the company Shinagawa for this project. Uniting companies that share the same purpose, always concerned in developing new products combining high performance with sustainability and safety. The methodology used aimed at evaluating the performance of refractory concrete from the BestDrying(PM) line using a 50% reduction of the drying curves. This reduction is possible due to the modified internal structure with high permeability of these materials. Conclusive results obtained point to financial and productivity gains and CO2 emission reduction in steel production. Also acting in the reduction of operational risks and increasing the flow stability. Therefore, the project allowed gains in productivity, sustainability, and operational safety.

Abstract:

This paper presents an optimization framework for scheduling torpedo car trips at Ouro Branco's steelwork. We discuss the problem's operational constraints and describe the proposed solution's architecture. In the end, we present the model performance results against real-world test scenarios.

Abstract:

The usage of Plant Information Management Systems – PIMS tools for monitoring, simulating, and integrating the production stages of industrial processes is an established reality in the Industry 4.0 context. Nevertheless, in research laboratories, the pilot scale equipment, insturments and analyzers used for new product development are usually isolated stations, each one with its own operating system, data bank and results exporting means. The requirements of speed, connectivity, efficiency, integration of Industry 4.0 have reached the development field in the form the Laboratory 4.0 revolution. This work is an overview of how Aperam South America’a research center has entered the Laboratory 4.0 era, by integrating its pilot scale thermochemical treatment equipment (continuous annealing and stationary annealing furnaces), instruments and analyzers to the PIMS architecture. And how the usage of tools for monitoring the equipment’s health and the process accuracy has helped to speed up and elevate the efficiency of the development process as a whole. The instrumentation and digitalization phases are described, as well as the monitoring and controlling applications that were developed, laying the groundworks for laboratory process modeling and simulation.

Abstract:

The preservation of natural resources and the reduction of environmental impacts are major concerns of the various economic, social, and environmental sectors, such as the cement industries responsible for the emission of millions of tons of CO2 per year from the Portland cement production. The search for binders with less environmental impact has grown, especially for those with reduced clinker content. In this context, the steel production, which generates a significant amount of waste and co-products, especially blast furnace slag and basic oxygen slag, can be a source of raw materials for cement plants. The results of this study demonstrated the possibility of developing a clinker-free cement, through the mixture of steel slag from blast furnaces and basic oxygen furnace and gypsum waste from civil construction, presenting hydraulic properties compatible with types of cement CPIII-32, CPII E-32, and SSC 32.5 N. It was possible to verify that the basic oxygen slag acted as a chemical activator, enhancing the hydration process of the mixture of blast furnace slag and gypsum.

Abstract:

Abstract:

In an integrated steel plant, where each process has its particularities, we have many contracts with third-party companies to support us in production. After a diagnosis, it was concluded that, in addition to the lack of standard criteria for contract management in the company, there were compliance risks and poor planning in this process. In this way, the new model establishes governance, transparency, and compliance in contract management. After a year of implementing a centralized area, this work shows the results achieved

Abstract:

The reduction of greenhouse gas emissions (GHG), increased energy efficiency, and the reuse of steel waste are crucial needs in the steel industry. One strategic technology that can contribute in this regard is the use of highly reactive coke (HRC) as a substitute for nut coke in blast furnaces. HRC is produced by carbonizing blends of coals and iron ore. This study examines the utilization of steel waste as substitutes for iron ore in HRC production, which is a strategic technology for reducing GHG emissions and improving energy efficiency in steelmaking. The effects of using these materials on the pyrolysis behavior and thermoplasticity of coal blends were evaluated. Additionally, the reactivity enhancement efficiency and mechanical strength of the produced HRC were investigated. The results demonstrated that, in addition to being technically feasible, this approach offers advantages for certain waste materials. For example, it is possible to obtain more resistant cokes by using wastes that exhibit less degradation of blend fluidity, as well as achieving higher reactivity with fine-grained wastes containing catalytic compounds other than iron.

Abstract:

Advanced high-strength steels (AHSS) were developed to meet the automotive industry demand for materials that allow the production of more resistant and lighter components. However, these steels have challenging requirements in terms of formability, both global and local, in which mechanical properties and microstructure have a great influence. Aligned with these challenges, Usiminas has been working to improve the quality of its products, seeking better performance during application. In this study, the effects of microstructure on the formability were determined for an 800 MPa dual phase steel, processed on industrial scale with two different conditions. The condition that led to a higher fraction of bainite, estimated by EBSD, showed higher FLCs, in addition to a 25% increase in hole expansion capacity and a considerably smaller minimum bending radius. The results show that the microstructural changes led to an increase in the global and local formability of the material, expanding the application possibilities, especially in components with more complex geometries.

Abstract:

The Brazilian ornamental stone sector has been growing and bringing new technologies for better use of stone materials intended for cladding in civil construction. However, there is a great environmental liability in this sector, due to the residues that are generated in different stages of the production process, which, in general, are sent to sanitary landfills. The use of waste for the manufacture of artificial stone ais one of the alternatives for the production of a technically viable material, aiming at the loss of waste and of great economic value. Over the last few years, Brazil and the world have been significantly increasing the production of artificial stones, being applied mainly in the finishing of civil construction, due to the quality of the final product and also its application versatility. This work aims to produce and technologically characterize an artificial stone with magmatic stone residue commercially known as Branco Fortaleza. Residual stones from the monitoring process of the slab block were used in the multiwire diamond loom equipment. The residues were used in three granulometric ranges (coarse, medium and fine) according to ABNT NBR 16.483/2020, where a granulometric composition of greater particle packing was determined. Regarding the epoxy matrix, plates with 12% resin were produced. For the production of artificial stone plates, the residues were mixed with the resin, and then a hydraulic press was used by vibration at a temperature of 90°C. The results of the technological properties of artificial stones showed good results and far superior to those adopted by the Brazilian technical standards ABNT NBR 15844/2015, and can be safely applied in civil construction. Keywords: Granitic stone waste; Epoxy resin; artificial stone.

Abstract:

Austenitic manganese steel, widely used in mining, combines metallurgical characteristics that combine high toughness with low abrasive wear. This phenomenon is due to the action of structural mechanisms activated by the surface hardening at work. The chemical composition of these materials has a fundamental behavior in terms of wear resistance. This study proposes the analysis of a percentage of 2% chromium in the characteristics of a Hadfield steel with a manganese content greater than 20%. Through Charpy impact tests and microabrasive wear tests, the conclusion was that the addition of chromium increases the abrasive wear resistance, but decreases de impact energy absortion.

Abstract:

The following work had the objective of implementing a set of improvements in the hot rolling process, aiming to reduce cases of non-conform products and its impacts in clients due to tangled coils. The methodology used in this project was the DMAIC roadmap (Define, Measure, Analyze, Improve and Control). Through this method, it was possible to involve a multidisciplinary team throughout each step of the project, to map relevant causes, prioritize and execute the action plan looking for mitigate occurrences of entanglement in the wire rod production. The main results attained were: 54% reduction in the non-conform generation, 67% reduction in the scrapping index and 34% in interruptions in the client’s machine

Abstract:

MicroSim Bars® and PhasTranSim® are tools developed to assist R&D engineers in designing steel products with specific metallurgical and mechanical properties. MicroSim Bars® is a modeling tool that simulates the evolution of austenite during hot rolling of steel bars, considering factors like chemical composition, temperature, and deformation conditions. It predicts changes in the steel's microstructure during the rolling process, crucial for determining the final properties of the product. On the other hand, PhasTranSim® is a simulation tool that focuses on phase transformations in steels after hot rolling, considering the transformation from austenite to ferrite, pearlite, bainite or M/A constituents. It helps R&D engineers to understand how changes in process conditions impact the steel's microstructure and mechanical/metallurgical properties. These tools aid in efficiently developing steel products with desired characteristics while it is possible to reduce the costs. This paper will explain these tools, the validation for their development and will explore a real case where the alloy design was optimized with a possible cost reduction.

Abstract:

In three years of operation, the waste stock achieved critical levels. All specific waste generations were larger than applications, making the scenario critical in the short term. With the aim of transforming the organization into a more sustainable company, with waste consumption greater than generation, projects were developed to reduce generations by increasing process yields and, projects were developed to optimize the applications of waste now generated. The results of the implemented projects positioned the organization as a national benchmark in terms of metallic yield between the Blast Furnace and Continuous Casting, favoring a reduction in waste generation by up to 30%. Innovative applications for scrap and aggregates were also developed, either recycling to the process and reducing costs, or in several different external industries. Finally, the equalization between generation and application allowed the reduction or even elimination of stocks of all classes existing inside the Plant.

Abstract:

During continuous casting of hypo-peritectic steel slabs, control of horizontal heat transfer rate in mold is important to avoid longitudinal cracks. This rate can be manipulated by mold slag crystallization. From an industrial situation where the longitudinal cracking index was too high, a new mold flux was designed with appropriate crystallization kinetics. The mold flux crystallization process was analyzed in the laboratory through differential scanning calorimetry. The Friedman isoconversional method was applied to determine the activation energy of crystallization from melt. Besides, a new quick test was developed to evaluate crystallization kinetics. The industrial tests have shown that the new mold flux decreases the longitudinal cracking index, and this is related to the decrease of horizontal heat transfer rate during the continuous casting process, which in turn is related to crystallization from mold slag.

Abstract:

One of the major challenges in actual market scenario is to guarantee the competitiveness with observance of environmental requirements. Steel ladle lining plays an important role on the energy consumption during the production and the refractory lining design contributes to minimize thermal bath loss and shell temperature. A new generation of unfired zero carbon refractories was developed with two specific approaches: i. replacement of firing bricks reducing CO2 footprint and ii. replacement of carbon containing bricks with better performance. Bricks can be used in working and safety linings with a unique microstructure with better heat scattering and similar thermomechanical properties. This work presents customers’ performance compared to traditional products highlighting energy savings

Abstract:

Plasma nitriding is a thermochemical process of technological importance to reduce damage on the steel surface, improving die life. However, the properties of this layer may change, due to the conditions of use of the die. The industrial environment submitted the nitrided surface to temperatures up to 600°C and, in the literature, there is not a clear understanding of the microstructural stability of nitrided surface properties. Therefore, the aim of this study is to evaluate the effect of temperature on the nitrided layer of AISI H13 steel. Samples were hardened and tempered to 45 HRC and then nitrided aiming for a layer with a depth up to 100 μm, without white layer. After nitriding, some samples were annelead in a furnace at 600°C for 30min, 2h, 5h, 10h and 100h. Some samples were tested for microstructure, x-ray diffraction and residual stress. The nitrated layer, after being subjected to high temperature, presents a reduction of level in the residual tensions of compression, bringing about a process of tensions relief. The same effect is not so strongly verified in the material hardness profile

Abstract:

Coking by-products play an important role in the economic well-being of the steel industry. The objective of this work was the design, construction and validation of a laboratory system that allows the study of the quality and yield of the 3 main coking products: coke, coal tar and coke oven gas. The apparatus consists of a coking retort, a cracking furnace and a glassware system. Validation was carried out by comparing the results obtained with industrial yields. The experiments were carried out with a heating rate of 3 ºC/min and a coking temperature of 1000 ºC. The operating parameters that best reproduced industrial conditions were cracking temperature of 800 ºC and coking time of 30 min. COG was obtained with a yield 4% above industrial. Coke and coal tar yields were obtained with a difference of less than 3%. Experiments in triplicate showed the degree of repeatability of the developed methodology. It was also possible to reproduce the industrial composition of COG, in particular of the two major gases (hydrogen and methane). Finally, the results obtained demonstrate the ability of the system to reproduce industrial conditions and allow the study of the contribution of coals and additives to the yield and quality of coking products.

Abstract:

Iron ore pellets are one of Brazil’s most exported commodities, companies present enormous production rates along with severe environmental challenges. As such, dust emission during the handling of iron ore pellets is the most important problem that needs to be addressed. Pellets present sizes in the range of 8-20 mm and cannot be dragged by windblown effects. But unlike ores, the underlying complexity lies in the creation of fine particles. Pellets suffer from abrasion, weakening, and breakage during handling, producing fine fragments that are emitted as dust. This work presents a methodology for the simulation of dust emission during handling of iron ore pellets. Surface and volume breakage mechanistic modeling is used to predict the amount and size of fragments. Standard computational methodologies such as DEM, CFD, and DPM are used for the simulation of the bulk behavior of the pellets, to obtain the energy of the stressing events, to simulate the air currents and to compute the trajectory of the emitted particles. Application of the methodology in an industrial scenario is presented to study advantages and limitations. Results show good agreement compared with observed results, demonstrating the value of the developed methodology.

Abstract:

This article presents the performance benefits obtained in SAG Mill grinding process of a gold plant at Kinross, located in Paracatu, MG, Brazil through the application of an Advanced Process Control system composed of MPC controllers (BrainWave® software) and supervisory logic (IDEAS™ software) responsible for performing the coordination of the entire unit operation, as well as setting optimized setpoints, activating/deactivating auxiliary controllers, managing process constraints and informing the operation team of the advanced process control status. The implemented control strategy seeks to reduce the weight variability of the SAG mill through the MPC controllers to maintain the optimum mill load by maximizing the feed and ensuring a good comminution performance. The advanced control system allows for autonomous and optimized operation of the SAG mill circuit with minimal interference from operators by manipulating key variables automatically and keeping equipment constraints within operating ranges. The benefits achieved were the reduction of weight variability, reduction of specific energy and increase in production rate.

Abstract:

The study presented here aims to discuss the improvements implemented in the desliming stage of Concentrator 3, at Samarco Mineração. Composed of a multidisciplinary team, several studies were carried out: simulations and dimensioning; laboratory tests (in batch mode); industrial tests (continuous), etc. After implementing low-investment (~R$156k) and low-complexity (vortex) improvements, it was possible to obtain considerable gains in Samarco Mineração's concentration processes. Taking 2015 as a reference, there was a 12% reduction in the percentage of ultrafines that would be sent to the Alegria Sul’s Cave – the disposal site for these tailings. The mass recovery of the desliming step had an efficiency gain from 89.8 to 91.0% - with no impact on quality and/or recovery in the subsequent step of flotation.

Abstract:

The flowing process of a blast furnace occurs through its tap holes. The tap hole hoods are the only area that do not have sealing in the reactor's communication with the environment, being made with refractory concrete. In pursuit of greater operational safety in the Blast Furnace, we focused on developing a philosophy of preserving the chapels in the holes through which more than 7,000 tons of hot metal flow per day. This maintenance process for the tap hole hoods is long and continuous. In this work we have the description of a methodology developed together with suppliers of refractorie materials, services and the the Gerdau’s Blast Furnaces technical team, with a focus on palliative repairs in intervals of operational campaigns of the runners and complete repairs, which they are carried out in scheduled shutdowns to recover the condition of the refractories along the entire length of the chapel and reduce gas leaks in this region. The repair philosophy and the systematics allowed the preservation of the refractory in this area, contributing to the reduction of gas leaks, cracks and mainly the chronic sinking of the hole region. Gains were obtained with the improvement in the quality of fillings in the tap holes, reflecting an increasing of 8% on average accuracy of tap hole’s length.

Abstract:

Internal collaborators and thirds parts are continuously challenged to develop innovative and integrated solutions inside steel industry to fulfill demands related to safety, sustainability and performance increasing. This paper aims to present an example on how a technological solution based on portable 3D laser scan technology is helping to achieve this goal. In this specific case, the usage of this solution is adding a new concept for refractory lining wear inspection in RH Degasser, reducing this process time and operator exposure. Finally, the data collected is being used to develop predictability refractory models, mainly for critical areas of this equipment.

Abstract:

Flotation is widely implemented in ore concentration as a technique to recover metals of interest in large capacities. It is a process deeply affected by disturbances in ore quality and other variables not predicted by the regulatory PID controls. Several types of advanced process control (APC) have been investigated to overcome this challenge, most not addressing all the constraints of the system properly. This work aims to present a use case of APC with adaptive control technology in a Pb/Zn milling and flotation circuit that addresses these process control challenges. The new optimization strategy seeks to improved ore recovery, while respecting reagents dosage, aeration profiles, and grade constraints. Air influx and reagents dosage were treated as economic trade-offs. APC implementation results showed an increase of 1.35% of Pb recovery, representing over 2 MUSD/year in benefits, with up to a 33% variability reduction in concentrate and tails grades. The additional dosage of reagents due to the increased recovery accounted for only forfeiting 3% of the total benefits

Abstract:

One of the greatest challenges of the mineral industry is to find a scalable, technically, and economically viable solution for tailings. They are generated during their production process. Faced with a scenario in which the scale of tailings generation is substantially more than the scale of potential solutions for consumption/reuse of tailings, the strategy adopted by Vale was to diversify the portfolio of applications for different business models. It is known that for every 1t of Vale sand destined, 1t of tailings will no longer be deposited in dams or piles. Currently, Vale generates around 70 Mta of tailings, and most of it has physical-chemical properties that allow it to be classified as ore-sand. For those mines where there is no possibility of any geotechnical structure, the destination of sand becomes vital for the maintenance of the company's core business (iron ore), since for every 1t of Vale sand destined, around 1.6 t of ore is released to be produced. The study carried out by UNEP indicated that Vale sand could reduce GHG emissions by 10 times, compared to natural sand. Brucutu was the first plant adapted to produce sand and since 2021 around 600,000t have been reused in different initiatives and applications: paving, concrete production, and others, reaching 1.0 Mt in 2023. characterizations, process route studies, and a detailed TML study to maximize national and international market opportunities.

Abstract:

With the advancement of studies in maintenance engineering, the real need to increase the production and reliability of a system with lower costs linked to this entire process is increasingly understood. And MRO material inventory management is one of the main pillars of these studies since well-planned guarantees a decrease in downtime, production stops and risks of material shortages. Thus this work through a case study in Ternium, a company located in the state of Rio de Janeiro, aims at the implementation of two systemic tools that were added to the material planning process and resulted in reductions, for example of more than 20% of excess materials, and in intensification of more qualified and technical information for better decision-making in the purchasing process, adjustments of stock parameters and need for stocking materials.

Abstract:

In this study, the volatile products of raw biomass and charcoal were evaluated for their reducing potential on iron ore. Firstly, biomass samples were heated to 1000°C under N2 atmosphere in a resistive furnace with continuous gas analysis. Following, these experiments were conducted under the same conditions, but with iron ore and biomass heated simultaneously. The gas analysis results showed the reduction of the ore by different reducing agents and the effect of the tar catalytic cracking, identified through interrupted tests at 600ºC. XRD results showed that magnetite was formed in all three ore particle sizes and biomass types, while wüstite was identified only when charcoal volatiles reacted with medium and fine ore. The interrupted tests showed the ability of the biomass volatiles to deposit carbon on the ore surface. After the experiments carried out up to 1000ºC, the wüstite morphology indicated that H2 was the main reducing agent in the ore heated with charcoal, while the deposited solid C was the reducing agent responsible for the ore morphology that was heated with raw biomass.

Abstract:

Multi-principal element alloys (MPEAs) or high/medium-entropy alloys are characterized by not having a well-defined solvent. More than a new class of materials, they represent a new conception of alloy’s design. Among the face-centered cubic (FCC) MPEAs, the Cr-Co-Ni system stands out for having toughness values among the highest ever observed for any engineering material. Additionally, alloying with small amounts of carbon can further elevate this property. As such, this study aimed to investigate the effect of carbon addition to a Cr-Co-Ni alloy and the effect of carbide distribution on the material’s hardness and microstructure. To achieve this, the alloys were produced and processed by two different routes: without and with a precipitate dissolution step. In the first case, a heterogeneous dispersion of second-phase particles was obtained, while for the second route, the distribution was homogeneous and more efficient in increasing the final hardness.

Abstract:

Port dredging is currently an important activity, as commercial demand has been growing exponentially. Thus, dredging is necessary to maintain adequate depth for navigation in port areas. Consequently, the amount of material dredged also increases, making it necessary to manage such waste. With the vision of circular economy and reuse, in addition to using less conventional materials in civil construction, the present work aims to produce a mortar where the lime binder will be partially replaced by Waste from dredging from Porto do Açu (RPA). Replacements are 10, 20 and 30% by mass in a standard mortar. Prismatic specimens (40 x 40 x 160 mm) were produced and kept at an average temperature of 25°C for 28 days. After the curing time, tests were carried out on flexural tensile strength, compressive strength, mass density and water absorption by capillarity. The results obtained were satisfactory, since the substituted mortar presented compressive strength and capillarity coefficient equivalent to the reference mortar, making its use possible..

Abstract:

Thin steel strip can contain non-metallic impurities like inclusions and segregations (NMI). They can vary widely in shape and size. The presence of NMIs can cause problems during the further processing of the material, especially during deformation. This creates the demand for a contactless online inspection system for the detection of NMIs to ensure the required product quality. IMS developed an online inspection system for NMIs based on magnetic flux leakage (MFL). MFL is already widely used in offline applications as magnetic powder testing. Compared to hall sensors, the use of sensitive GMR sensors leads to an increase in liftoff while improving sensitivity. The Sensors, magnetization, amplification, and digitalization are incorporated into a compact device acting as a MFL line camera. These devices can be combined in different numbers and configurations, enabling a gap-free coverage of inspected strip. Their data is transferred to the image processing computer by the standard Gig-E interface. The signals of defects are separated from the background noise and classified by an image processing software. It generates a defect map of the strip showing the different defect classes. That information helps in grading the produced material and in optimizing the production process.

Abstract:

Clutch bearing rings are high-performance parts that require exceptionally good cleanliness and microstructure homogeneity to meet their wear and fatigue requirements. In order to improve productivity and reduce costs, a modified Cr alloyed steel with high carbon content has been developed by bearing manufacturers in cooperation with steel producers, which is well suited in terms of formability and is widely used in the production of automotive components, where it is purchased in the form of the cold-rolled strip for forming. In this work, the process parameters, and critical characteristics for the development of a Cr alloyed sheet steel with high carbon content to produce clutch bearing rings were investigated on an industrial scale. Tensile test, hardness test, optical microscopy (OM), and scanning electron microscopy (SEM) were used to evaluate the mechanical and metallurgical properties of the studied steel throughout the process (casting, hot rolling, cold rolling + batch annealing, and heat treatment). The results have shown that it is possible to tune the mechanical properties of high-carbon sheet steel by suitable heat treatment and metallurgical treatment at each stage of the process.

Abstract:

The forming processes generate a significant volume of material discarded in the form of flash. Many processes yield burrs with a circular section and limited thickness. This material traditionally returns as scrap to the raw material production sector. This study proposes to evaluate the reuse of AA6351 aluminum alloy flash available in the form of discs in the closed die hot forging process. In the process, the flashes are stacked to form the billet which is forged at 500°C to produce a flange. The obtained part is analyzed and compared with a part obtained in the conventional forging process with a cylindrical billet. Both processes are investigated troughth numerical simulation.

Abstract:

It is known that the steel market is extremely dynamic, with a continuous search for product innovation (application and quality) and processes (financial and environmental sustainability). After the unique effect of the global COVID-19 pandemic on steel demand and production in the period, efforts were made to establish a plan to resume production with maximum efficiency and profitability by enhancing the production mix by increasing the percentage of high aggregate value steel or high-tech steels. However, for the production of steels with higher quality requirements, there is generally a higher level of demand for equipment and processes, mitigating or creating new production bottlenecks. The discrete event process modeling technique is very suitable for this environment, as it allows the current situation of the plant to be accurately modeled, the true bottlenecks for a given production plan or expansion of production capacity to be verified, and to avoid disastrous surprises in decision-making, for example, as in an investment plan. This work was developed through a real project carried out at the ArcelorMittal Pecém plant, with the objective of investigating the impact of the increase in the production of steels with calcium and will present how the engineering method proposed by the computational simulation of the productive process is a robust and efficient tool. reliable for a vision of the future and identification of production bottlenecks in a steelmaking.

Abstract:

Macro and micro segregation play a key role in understanding the solidification behavior of continuously cast steels. Both affects directly critical applications, which requires a higher degree of homogeneity since as cast stage. This study applied macro and micro approaches to perform a comprehensive characterization of the solidification microstructure for wide slabs. In the macro-approach, a width-wise chemical analysis was performed using OES on whole centerline. Thickness-wise analysis was also implemented at 300 mm intervals in width direction. Carbon content in centerline was almost three times higher than base chemistry. The same behavior happened with P, S, Ti, and Nb. The micro-approach in this study considered SDAS (Secondary Dendrite Arm Spacing) and second phase particles. Calculated figures presented particularly good correspondence with measured ones for both micro-approach features. Liquidus and solidus position, as well as mushy zone were calculated using CON1D model. NbC and MnS were the most relevant second phase particles calculated by Factsage. This finding matches to the analysis carried out by SEM-EDS. Based on these results, which measured values were in good agreement with calculated ones, it is possible to estimate the internal quality of slabs in a higher degree of confidence.

Abstract:

Steel ladle is steelmaking process pillar, it participates in all steps of secondary refining, from BOF/EAF liquid steel receiving to casting it into the tundish. For this reason, the refractory lining, mainly precast bottom, underwent a various development to withstand the severe operating conditions, due to the strictest quality requirements, such as: chemical reactions, temperature changes during the process, oxygen blowing and vacuum conditions. In order to meet operational requirements, Vesuvius has directed efforts towards the development of high-performance lining associated with technological solutions, which combine a high installation rate, low cost, operational safety and good ergonomic conditions for employees. Additionally, extending bottom life for more than one campaign, uses carbon-free castable and reduction of metal loss due design enabled significant gains in relation to sustainability. In this context, results of laboratory and industrial tests are presented and discussed, as well as the precast bottom benefits for steel ladle as a replacement for the standard brick lining.

Abstract:

This paper presents the effects of Niobium additions (1, 2 and 3%) on the wear resistance and impact properties of Hadfield steels (1.2%C and 12-18%Mn). The additions of Nb promoted a significant decrease in the mass losses, from 79 mg (Hadfield steel with 12%Mn) to 33 mg (Hadfield steel with 3%Nb) in the abrasive wear test (rubber wheel); and from 29 mg (Hadfield steel with 12%Mn) to 24 mg (Hadfield steel with 1%Nb) in the friction wear test (pin on disc). The results showed a reduction in the energy absorbed in the impact tests proportional to the Nb content (from 200J in the standard Hadfield steel to 53J with addition of 2%Nb).

Abstract:

The present paper aims to present a new methodology to measure the thermoplasticity of coals by the permeation distance method. This development is a reproduction of a methodology created at JFE Steel and adapted to the reality of the coals used for the production of metallurgical coke in Brazil. This method consists of evaluating the thermoplastic behavior of coals in a complementary way to Plastometry and Dilatometry analyses. Experiments were carried out for coals of different ranks and petroleum coke. Furthermore, the hypotheses of additivity and tests with different particle sizes for the same coal were validated. It was concluded that there are significant differences between permeation distances for coals of the same fluidity, with emphasis on the anomalous behavior of the CVP and that the granulometry is a relevant factor for the permeation distance with an impact on the quality of the semicoque, with a direct influence on the mechanical resistance of metallurgical coke.

Abstract:

Industries and governments are facing increasing pressure to commit to decarbonization efforts, conduct research, test, and implement best practices to achieve the target of limiting global warming to below 1.5/2 °C. The steel sector is a significant contributor, accounting for around 7% of global CO2 emissions and energy consumption. To address this issue, significant efforts are required. This article explores the potential of using biochar and bio-oil as alternative fuels for pellet production in Brazilian and Canadian iron ore pelletizing plants, highlighting successful application cases in both countries. It also discusses the results of a research program at COREM's innovation and research center. The final section focuses on the challenges of ensuring the supply chain for biofuels, comparing the scenarios of Brazil and Canada.

Abstract:

Simulation using the discrete element method (DEM) coupled to computational fluid dynamics (CFD) to describe the behavior of the grinding media and the slurry inside the pilot stirred mill, and thus, added to the UFRJ mechanistic grinding model, assess the effects of the agitator speed, slurry flowrate, percentage of solids and feed size distribution in grinding. The pilot stirred mill has been described using three equally-sized perfect mixers connected in series coupled to an internal classifier, which is described by means of DEM-CFD-DPM. All variables promoted significant changes in the size distribution of the product. However, although this approach demonstrated the influence of some operational conditions on classification, it is shown that the classification effect is significant only when the percentage of solids in the slurry is low and the size distribution was coarser.

Abstract:

As iron ore producers look to minimize their ecological impact, low carbon technologies such as direct-reduced iron (DRI) are gaining increased interest. DRI requires high-quality iron ore feed with stringent quality requirements, making the upgrading of the concentrate necessary. Beneficiation processes such as flotation, magnetic separation, gravity methods, and classification by size can be considered, alone or in conjunction. This paper explores the application of fine screening technology in direct-reduced iron (DRI) production. The mechanisms of screening are discussed with particular focus on how they differ from conventional hydrocyclone technology. Screening can be employed at a variety of applications in an iron ore concentration plant, but the most effective strategy for high purity concentrate is a fundamental shift in the grind-grade relationship in the milling stage. Two historic case studies are explored demonstrating how this has been employed historically.

Abstract:

Refractory suppliers face continuous challenges in developing innovative solutions for blast furnace taphole plugging. This paper highlights special taphole clay solutions for optimal operational stability and hearth wall preservation. Innovative technologies have been developed to address specific applications, such as taphole clays for crack sealing, taphole length recovery, consecutive taps, hot spots and eco-friendly refractories, together with continuous improvements of materials for standard applications. The implementation of these taphole clay solutions has resulted in better blast furnace operations and extended campaigns.

Abstract:

In the Mining sector, the productivity and cost of the operation depend directly on the efficiency of the services provided by the contractors to work in the field. Our objective in this study was to develop a solution that would allow the monitoring of more than 500 (five hundred) equipments that are allocated to Samarco in its works at the Germano Mine/MG, considering its particularities, but without increasing too much human effort in this process of control and inspection. The monitoring method is based on geographically separating the areas where this equipment will travel, locating them through georeferencing and monitoring their telemetry data to serve different purposes. We are currently with effective results in controlling speed limits, for work safety purposes, and are already initiating work on classifying the operation of machines in productive, unproductive and unavailable hours of this equipment. Still for the year 2023 we intend to start two more case studies to address productivity and sustainability issue.

Abstract:

INEFFICIENT PROCESSES MAKE AN INEFFICIENT COMPANY. IN A MARKET THAT IS DIFFICULT TO DIFFERENTIATE, OPERATIONAL EFFECTIVENESS AND EFFICIENCY CAN MAKE ALL THE DIFFERENCE. IN THIS WORK WE WILL ADDRESS THE IMPLEMENTATION OF THE ITIL LIBRARY (INFORMATION TECHNOLOGY INFRASTRUCTURE LIBRARY) FOR THE MANAGEMENT OF INDUSTRIAL AUTOMATION SERVICES AT SAMARCO MINERAÇÃO S/A. AUTOMATION PLAYS A CRUCIAL ROLE IN THE MINING INDUSTRY, OPTIMIZING PROCESSES, INCREASING OPERATIONAL EFFICIENCY AND ENSURING WORKER SAFETY. HOWEVER, THE COMPLEXITY OF INDUSTRIAL AUTOMATION SYSTEMS REQUIRES A STRUCTURED APPROACH TO EFFICIENTLY MANAGE YOUR SERVICES. THE IMPLEMENTATION OF ITIL ALLOWED THE COMPANY TO ADOPT BETTER PRACTICES FOR THE MANAGEMENT OF AUTOMATION SERVICES, INCREASING THE CONTROL AND QUALITY OF PROCESSES. BY ANALYZING AND OPTIMIZING INCIDENT, PROBLEM, CHANGE, AND CONFIGURATION MANAGEMENT PROCESSES, THE AUTOMATION TEAM WAS ABLE TO REDUCE SYSTEM DOWNTIME, IMPROVE PROBLEM RESOLUTION, AND IMPROVE EQUIPMENT AVAILABILITY AND RELIABILITY. IN ADDITION, THE IMPLEMENTATION OF ITIL PROVIDED A CULTURAL CHANGE PROMOTING A MORE PROCESS-ORIENTED, COLLABORATIVE AND PROACTIVE APPROACH. INTERNAL COMMUNICATION HAS BEEN IMPROVED, ALLOWING FOR BETTER COORDINATION BETWEEN TEAM MEMBERS AND FASTER RESPONSE TO INCIDENTS AND USER DEMANDS.

Abstract:

Abstract:

The implementation of World Class Maintenance, or WCM, and the standardization of its routines provide sustainability of the production process’ results, maximizing the availability of assets for operation and optimizing maintenance costs. Within this concept, this work, through a case study carried out in Ternium company located in the state of Rio de Janeiro, aims to present the structure carried out on the current maintenance strategy in the company to integrate it to the MCM concept and reach its first pillar, productivity. After the implementation of the methodology, there was a 25% reduction in unavailability and allowed the actions taken to be continuously revisited, generation a cycle of constant critical analyzes and increasingly fostering a cultura of innovation in the company.

Abstract:

Tecnored SA has acquired a consolidated knowledge of briquetting through the development of the Tecnored process, which uses briquettes as raw materials. Now, the company is developing briquettes that also help in the decarbonization of the AF/LD route. One such product is CBB, made from metallurgical coal, charcoal, and iron ore. CBB can partially or fully replace small-coke, reducing blast furnace temperature, coke consumption, and CO2 emissions. The study describes the development of CBB at laboratory scale, considering different carbon sources, binders and carbonization variables. The results show that CBB made with more flowable coal has higher mechanical strength. Briquettes carbonized at lower temperatures also have higher mechanical strength but lower metallization. However, even with lower metallization, CBB showed high reactivity, with gasification start temperature of 902ºC. These results indicate that CBB can reduce fuel consumption and CO2 emissions.

Abstract:

The nickel alloy VAT80A exhibits high mechanical strength at high temperatures due to γ'- phase (Ni3Al) precipitation. In this work, the effect of chemical composition on the relationship between austenitic matrix and γ' precipitates and the stress-rupture resistance was studied. Thermodynamic simulations supported by Thermo-Calc, DTA and X-ray diffractometry analysis were performed. The simulation results were consistent with the data collected in the DTA tests. The increase in aluminum and titanium contents were correlated to the increase in the solvus temperature for the γ'- phase, the misfit increases between the γ and γ' lattices and the consequent increase in the mechanical property of the material.

Abstract:

Residual stress is one of the main factors affecting the mechanical properties of materials, such as their strength, plasticity and surface integrity. In the hot rolling processes, materials can be deformed nonuniformly due to external influences, such as an uneven mechanical deformation, a temperature change or a phase change, resulting in a flatness defect or residual stress. Measuring residual stress is important for evaluating the quality and safety of steel sheets, but traditional methods such as hole drilling and X-ray diffraction have limitations when measuring residual stress in hot-rolled steel plates. The Barkhausen method, which measures the magnetic field emitted by the material during the application of an alternating magnetic field, can be used to measure residual stress without making additional cuts in the plate. The method was developed to evaluate the residual stress behavior in the cross section of a hot-rolled SAE1010 steel plate and compared to the hole drilling and X-ray diffraction methods.

Abstract:

Today, success in the wirerod market can be achieved only by combining high plant productivity, efficiency, superior-quality finished products and plant flexibility. These requirements, in addition to Danieli’s latest research efforts and industrial setup activities, point the way to environmental sustainability, true green-steel production and the adoption of a circular economy model, as seen in the tangible results achieved by the ABS QWR 4.0 project, which rolled the first billet on November 27th, 2020, and now after two and a half years, is considered a word leader and benchmark among the wire rod suppliers

Abstract:

The development of 0.35 and 0.30 mm thickness cold-rolled steel process for low strength steels at Usiminas’ Cubatão plant has become more demanding by the flat steel market in terms of smaller thicknesses of cold-rolled material. In addition, it is possible to expand to the coated steel market that requires lower thicknesses with high cold thickness reduction. These thicknesses exceed the capacity defined at the 4-high Tandem Cold Mill specification, which was specified for 0.38 mm, the minimum thickness. For the process of this material, changes were made in the process parameters and stands’ cooling system. The changes aimed to ensure the quality of the rolled strip, without compromising the safety of the process and the integrity of the equipment. The rolling conditions parameters and the quality of the product were satisfactory in both dimensions and chemical compositions, reaching surface, dimensional and shape quality required by the product.

Abstract:

With the purpose of producing "Smart steels for people and the planet", ArcelorMittal Tubarão seeks to reduce carbon dioxide (CO2) emissions in its production processes (decarbonization). One of the medium-term initiatives (2030), where the group intends to reduce 25% of gas emissions globally, is to increase the consumption of steel scrap, reducing the consumption of liquid pig iron. This will require major structuring in the process of logistics, processing, production planning, and equipment to support the larger volume of scrap needed for the project. The increase in the consumption of recycled steel scrap generates an increase in the total sum of residual elements in the final chemical composition of the steel, being a point of attention for the structuring of controls, separation and classification of scrap to be consumed.

Abstract:

The demand for specific steels, as well as high quality and cleanliness requirements challenge the steel industry to seek different processes to meet the increasingly demanding market. Motivated by these facts, the present work aims to evaluate the influence of argon injection in different tundish upper nozzle to reduce the agglomeration of inclusions with high melting point that may adhere to the inner wall and avoid clogging during the continuous casting of slabs. Steel samples with inclusions were taken inside the tundish upper nozzle and characterized using optical microscopy, scanning electron microscopy and Spark-DAT. As a result, it is expected to identify the characteristics of the inclusions formed in the region of the upper nozzle and their volume, as well as the influence of argon injection in the upper nozzle to reduce clogging events with a consequent increase in the casting machine productivity and improvement in the steel cleanliness

Abstract:

The steel ladle's refractory service life suffered a considerable reduction in performance. Historically, the main region that limits the equipment's lifetime is the slag line purging panel, near the porous plug, which presents low residuals at the end of each campaign due to corrosive and erosive phenomena, the latter mainly caused by the influence of gas injection of bubbling system. In this context, a simulation study was carried out to investigate the effects of moving the purging plug away from the ladle walls. The simulation study compared the reference plug position with two new alternatives: the first one, moving the plug vertically by 100mm from a top view perspective, and the second one, moving the plug radially by 141mm (100mm on both sides from a top view perspective). The simulation results show that changing the plug position has a positive impact on wall wear, reducing the maximum wall shear stress by 29% in the first position alternative and by 50% in the second position alternative. As the second position alternative presented the best results, it was adopted in plant trials. A total of seven full campaigns were tested using the new position, and the results showed a considerable increase in ladle performance, with a potential service life of 97 heats and a wear rate of 1.7mm/heat, which is about 23% lower than the average value of 2.2mm/heat in the same period.

Abstract:

In the current scenario of competitiveness and challenges for the steel industry, there is a need to increase the consumption of materials of lower quality and price to reduce the cost of coal blends. The main objective of the research is to maximize the high inertinite content coal in the industrial coal blend by selective crushing of inert coal with reduction of the size of maceral particles of the inertinite group by decreasing microcracks at boundary between inert additive and coke matrix. The properties of coals and proposed blends were characterized by reducing the ratio between reactive and inert maceral, studying the effect on coke strength and its microstructure changes. Results demonstrated that it is possible to increase from 6 to 20 % the participation of high inertinite content coal in an industrial blend without impact of the quality of the coke, by selective crushing of the inert coal, aiming to reduce the average size of coal particle to the value 1.5 mm as the critical inert size for coke mechanical strength.

Abstract:

This paper aims to investigate the usage of water for pellets bed humidification in a conveyor belt to improve the cooling processes and minimize dust emission during pellets transportation. Laboratory and field tests were carried out to understand the effect of pellets moisture on particulate matter emissions, the impact of solar irradiation on the moisture index, the interference of pellets porosity and the water penetration in the pellets bed layers. The results show that quantities about 2% of water content drastically decreases dust emissions (over 95%) if compared to emissions caused by dry pellets. The moisture index decay rapidly due the solar irradiation, the moisture is not uniformly distributed if water is applied superficially in a conveyor belt and the iron ore pellets, due to its porosity (ranging from 30% up to 42%) were able to retain moisture in their cores.

Abstract:

Simulation is a widely used tool for optimization of comminution circuits in the mineral and metallurgical industries. However, it is typically performed in steady-state, which is rarely achieved in industrial operations. Dynamic simulators exist, but they are very expensive and contain only a limited number of mathematical models. To overcome these challenges, the dynamic simulator Dyssol was developed, being verified in the present work. The work began with the implementation of models for transformation, classification, transport, accumulation, and control units. Then, simulations of aggregate crushing and Portland cement grinding circuits using Dyssol were compared to those using the Matlab/Simulink platform. Results showed that Dyssol was able to replicate the expected results, both numerically and in simulation time, and proved to be an excellent tool for dynamic simulations involving particulate materials.

Abstract:

The flotation has been successfully applied to process the iron ore for the particle size range between 10 and 150 µm. The presence of the slimes are harmful on the reverse flotation of quartz, so they are prior removed by hydrocyclones. The main effects of the presence of slimes on the flotation are related to the increase on reagents consumption, the stability of the froth and decrease on the selectivity. The lower flotability of coarse quartz particles +74 µm combined with the presence of slimes, even in small quantities, drastically affect the flotation response. This paper shows a study of characterization of typical iron ore slimes and alternatives of concentration using column flotation with collector amide-amine without depressor and pH 8.5, vertical pulsation high magnetic separation and no traditional methods as acid leaching with Fe-oxides recovery by pyrohydrolysis. The main characteristics of the slimes from the Iron Ore Quadrangle in Brasil are the presence of almost 70% of Fe-oxides (hematite and goethite), 25 % of quartz 4% of kaolinite as the main silicate minerals. Furthermore, more than 80% of the hematite and the kaolinite are below 20 µm, about 20% of the hematite is associated with 14% of quartz and 6% of kaolinite, where these aluminium-silicates appear as dispersed particles smaller than 2 μm. The affinity between the ultrafine kaolinite of the slimes with the corn starch is harmful to the reverse flotation of quartz. The presence of pure kaolinite can also totally inhibit the flotability of pure quartz even with high dosages of eterhamine. Column flotation using no traditional collector named amide-amine without depressor and pH 8.5 followed by vertical pulsation high gradient magnetic separator (VPHGMS) enabled almost 70% Fe recovery and ultrafine pellet feed with 66%Fe. Chloride acid leaching with pyrohydrolysis for the column flotation and VPHGMS tailings increased Fe recovery to 98% with slight increase of Al2O3 and P for the final concentrate.

Abstract:

This article presents a new digital method to improve the labors safety during the measurement of the remaining working blast furnace runner refractory castable. During the drainage of the runner, it is necessary to verify its dimensions to plan the next refractory maintenance and better estimate the runner’s campaign. Due to the refractory wall high temperatures (above 400ºC), the environment becomes hazardous and prone to safety deviations. Facing the impossibility to perform a reliable measurement under hot environment, Ternium Brasil joined RHIMagnesita in a new development seeking the safety for its employees and accuracy in its processes. The methodology consisted of replacing the conventional daily manual approach for the 3D laser scanning method. As a result, the 28 hours of weekly employees’ exposure was eliminated, as well as the risk of falls and inhalation of gases and vapors. By measuring the wear through symmetrical 3D technology, it was achieved greater reliable data for the decision-making, resulting in the optimization of the refractory specific consumption while increasing the blast furnace runner’s availability. The 3D laser scanning method contributed for achieving a better refractory wall wear management, which resulted in a safer and more reliable process; could it be a 100% sustainable?

Abstract:

In any modern industrial process, one of the biggest challenges faced is maintaining a consolidated database so that it can be the main source for analysis and decision-making. Different processes and actions of those involved contribute to the creation of different versions of industrial facts: indicators, adopted constants, and even process data may differ between areas or even between shifts in the same area. The objective of this work was to develop a unique integrated view of the entire bauxite custody chain, from mining fronts to dewatering for Alunorte, to ensure reliability and fast availability of industrial data from different sources for those who need it, and to provide production and quality information for batches and production lots throughout all stages of the bauxite production cycle. Additionally, based on the availability obtained for the information, reports, and dashboards that used to take long periods to build were automated, freeing up valuable time for analysis and assertive decision-making. The work developed in this project lays the groundwork for future advances in more complex analyses, such as machine learning solutions, which will allow for quality predictions and early corrective actions.

Abstract:

The current study, developed in ArcelorMittal Tubarão steel industry, proposes an integrated approach methodology, based on ITSM, ITIL and PMBOK best practices, for implementation of an IT and Automation (PA) infrastructure Moving project, focusing on delivering quality services, aligned with business needs e within deadlines and established budgets. This paper highlights the intrinsic challenges to industrial environment complexity, explore the opportunities for technological modernization triggered throughout the project phases, presents the benefits generated with the transitions, as well as shares the captured learnt lessons, as a contribution to future implementations and synergies with other units and companies with similar objectives.

Abstract:

Abstract:

The following work had as its main objective the evaluation of superduplex steel S32750 after being subjected to a corrosive environment of 15% hydrochloric acid at room temperature in a deaerated environment, with 4% oxygen, typical operating conditions in the industry. A total of 9 samples were analyzed, 3 samples having been exposed to the acid solution for 47 h (1.96 days), 3 samples for 239 h (8.12 days) and 3 samples for 601 h (25.04 days) .The effects of corrosion on the microstructure of the material with a thickness of 2.8 mm and a diameter of 25.4 mm were evaluated, when subjected to a 15% HCl solution and a stress that simulates the mechanical efforts of operating pressure. No corrosion inhibitor was used in order to maximize the effects of corrosion on the material. The microstructural characterization was carried out after the corrosion test using optical microscopy and confocal microscopy techniques. The uniform corrosion rate due to mass loss was also evaluated. The samples suffered progressive corrosion, according to the number of test days, being classified as selective corrosion of the ferrite phase and of the austenite-ferrite boundaries.

Abstract:

Corrosion is a critical problem in all industries and as a result of corrosion reactions, it is estimated that 5% of an industrialized nation's income is spent due to the need to replace lost or contaminated equipment and to prevent corrosion. In the sugarcane industry, corrosion is a common phenomenon, since the composition of the juice favors this process in different types of equipment. The aim of this work was to evaluate the corrosion resistance of alloy steels in sugarcane juice environment, in order to identify materials that have good mechanical and corrosion resistance. Immersion corrosion tests were carried out at different times and under different conditions in order to evaluate the influence of the variables on the corrosion rates, which were determined using the mass loss method. The microstructural characterization of the steels allowed understanding their corrosive behavior and verifying the heat treatments performed. The results showed that the corrosion resistance of a material depends on its microstructure and chemical composition. The constant change of corrosive fluid interfered in the results, causing the breakdown of the protective oxide film formed on the surface of the material. The results emphasize the importance of performing corrosion tests with well-defined parameters.

Abstract:

In this work, the influence of the ionic liquid (3-indolymethyl) trimethylammonium iodide was evaluated as a corrosion inhibitor in the corrosive medium of hydrochloric acid for duplex stainless steel S31803 welded by the TIG process and thermally treated. The microstructure of the sample after welding and heat treatment was analyzed before the corrosive process, using the technique of confocal microscopy, in order to analyze the concentration of the phases. Then, the mechanical tensile test was performed. The corrosive process was performed using 1M hydrochloric acid solution and 1M hydrochloric acid solution containing 0.4mM of the proposed ionic liquid. The microstructure of duplex stainless steel S31803 is composed of two phases, ferrite and austenite, with an approximate balance of 50% by volume of the phase fractions present. The welding and heat treatment process was not able to cause negative damage to the mechanical properties of the material. The HCl corrosive medium without the corrosion inhibitor provided uniform corrosion development on the material. Deterioration of the passive film was observed, significantly increasing the corrosion rate. The corrosive medium containing the ionic liquid, developed uniform corrosion in the material, but its rate was 40x lower when compared to the sample without the inhibitor. In the end, it was concluded that (3-indolymethyl) trimethylammonium iodide presented an efficiency of 30.14% when used as a corrosion inhibitor.

Abstract:

NiTi metal alloys manage to recover their original shape after deformation, removing the charge. They have unique thermomechanical properties with several applications. However, corrosion can cause premature failure of devices containing NiTi. Many characteristics qualify graphene as a material for anti-corrosion coatings. Graphene has high chemical inertness requiring functional groups to react with metallic substrates, leading to low adhesion strength. As a derivative of pure graphene, graphene oxide (GO) and reduced graphene oxide (rGO) have many functional groups containing oxygen on their surfaces, improving their dispersive capabilities in water or organic solvents. The aim of this study was to compare the performance of two anticorrosive films on the surface of a NiTiꓽ alloy, one containing GO and the other rGO. The superelastic NiTi alloys were coated with a flexible nanometer film using the Dip-coating technique. These coatings were characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-Ray Diffraction (XRD). The corrosion resistance of the coatings was studied using potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) techniques. The results showed a significant improvement in the corrosion resistance of the coated alloys.

Abstract:

This work aims to evaluate the effect of voltage on the anodizing process of a commercial aluminum alloy and the relationship with corrosion resistance in acid medium compared to the as received (not anodizing) alloy. Anodizing was performed at two different voltages: E = 16 V and E = 24 V, for 1 hour. The anodizing bath consisted of a sulfuric acid solution at a constant temperature of 5ºC, naturally aerated. The micrographs showed that the samples anodized at higher voltages presented a greater thickness of the oxide film formed. Electrochemical tests show that anodizing at both conditions promoted an increase in the corrosion resistance of the aluminum alloy.

Abstract:

The objective of this work is highlighting the technological control developed to guarantee all the traceability and reliability of the information obtained during the whole work of Adequacy of the Constructive Method of the Barragem dos Alemães through BIM (Building Information Modeling). To guarantee all the documentation of the activities carried out, from the initial phase of prospecting the borrow areas, receiving and characterizing aggregates, cleaning and treatment of the foundation to the application of materials according to the technical specification, a set of controls was developed that allowed BIM to compile all information in an accessible and clear way. The results obtained were assertive controls, proof of the execution of activities on the embankment, draining elements (vertical filter and horizontal blanket), surface drainage and project change notes. It is concluded that the controls data compiled in BIM ensured the traceability and reliability of the information quickly, since the metadata is available in a three-dimensional way, allowing the visualization of the results.

Abstract:

This article outlines how an expert system, specifically Leaf, a software developed by iSystems utilizing Fuzzy controllers and custom programming logics, was applied to the crushing circuit of AngloGold-Cuiabá mine to improve productivity. Following the deployment of Leaf, a 19 t/h increase in production was observed when comparing data from the periods before and after the implementation.

Abstract:

Lithium compounds have been widely researched due to the increased commercialization of electric and electronic vehicles that have lithium-ion batteries. Lithium is a metal from the alkali family, being very reactive and having the lowest density among metals, with 0.534 g.cm-3 at 20 °C. In Brazil it is extracted mainly from spodumene ore by the traditional alkaline or acid process. In the present work, a survey was carried out on exports and imports of spodumene, carbonate and hydroxide compounds, in addition to products containing it, evaluating the behavior of the price per ton (US$/t) in Brazil. The data used to carry out the study were obtained through the Integrated Foreign Trade System (SISCOMEX) platform between the years 1997 and 2023. It was observed that spodumene and lithium carbonate are the products of greatest Brazilian export, and Electric vehicles have been widely imported into the domestic market.

Abstract:

The safe disposal of mineral tailings is a major challenge for the sector towards greater sustainability. The objective of this work was to study the dewatering of iron ore tailings in order to improve the efficiency of solid-liquid separation operations, such as aggregation and thickening, and consequently, the stability for disposal in tailings dams or dry stacking areas. For this purpose, the polymer Magnafloc®5250 was used as a flocculant, varying the dosage up to 120 g/t; the efficiency of solid-liquid separation was analyzed by means of measurements of sedimentation velocity and turbidity of the supernatant, and the consistency of the sediment, by rheological tests with the Vane geometry and slump tests. The thickened tailing was subjected to filtration tests, evaluating the influence of flocculant polymers on the unit filtration rate (TUF) and final moisture content of the cake. The results show that the polymer is efficient in the aggregation/sedimentation of particles, producing thickened tailings with high consistency and significant reductions in filtration time for cake production, being safer for environmental disposal.

Abstract:

Rare-earth elements (REEs) are especially relevant to produce luminescent materials, magnetic alloys, and even catalysts. Monazite is a REEs phosphate that has 21.93 Mt with 2.35% to 3.02% of rare earth oxides contained, located in Araxá-MG, Brazil. This work proposes an alkaline conversion under high pressure with NaOH solution, followed by hydrochloric leaching of REEs’ hydroxides route. The authors designed a Plackett-Burman design of 8 tests, 5 factors and 2 levels (high and low) for the alkaline conversion. The leaching had no parameter variation. The analysis of the effect of the variables on the extraction of Fe and La was performed using Pareto diagrams. In them, it was identified that concentration and temperature are positively significant for both elements and that the solid-liquid ratio is negatively significant for lanthanum. Agitation and reactional time were not significant in any of the elements. A desirability function was also made to maximize %La and minimize %Fe. From these analyses, the authors concluded that, in order to improve the process, it is necessary to carry out a new experiment with lower solid-liquid ratios and temperatures, and higher concentrations of NaOH

Abstract:

This work has for objective to reformulate a typical roofing tile body from Campos dos Goytacazes with additions of shale powder from Itu, sedimentary rock extensively used for the production of structural ceramic in that region. Compositions with a plastic clay from Campos dos Goytacazes and 30, 40, and 50 wt. % of shale powder were prepared and characterized. The properties and characteristics of the compositions with shale were compared with a roofing tiles body from the north-fluminense region. To determine the physical and mechanical properties specimen were prepared by extrusion and fired at temperatures varying from 800 to 1050oC. The technological properties evaluated were: bulk density, linear shrinkage, water absorption and flexural rupture strength. The results indicated that the use of shale clay powder could improve the performance of the industrial roofing tile produced in Campos dos Goytacazes

Abstract:

Abstract The objective of this research is to evaluate the incorporation of corn straw fiber in mortars in the proportion 1:1:6:1.55 (cement: lime: sand: water) using 0%, 2.5% and 5% of natural fibers and fibers treated with sodium hydroxide (soda). To achieve this objective, the natural and soda-treated fiber was characterized by scanning electron microscopy (SEM) and x-ray diffraction (XRD). In addition, consistency, compressive strength, water absorption and density properties were evaluated. Cylindrical specimens of 50x100 mm were produced and cured for 28 days with specimens submerged in lime solution. In the results of characterization of the fibers, it was observed that the treatment in sodium hydroxide increased the crystallinity of the fibers and increased the roughness of the fiber. In addition, it was observed that the soda treatment allowed the application of corn straw fibers, since the compositions with natural fibers showed a considerable drop in compressive strength, while the compositions with treated fibers showed statistical equivalence. The treatment also reduced the water absorption of mortars. Thus, it is concluded that the corn straw fiber is viable for use in mortars for coating and laying blocks only after treatment with soda

Abstract:

In this research, the analysis of the partial replacement of 10 and 20% of Portland cement by silica fume was carried out. The main difference between this research and similar ones is the analysis of the use of silica in an activation process with NaOH and KOH. For this, 50x100 cm cylindrical specimens were produced. Active silica was used as pozzolana, for comparison purposes, and with material activated by NaOH and KOH. Fresh state properties, such as consistency and squeeze flow, and hardened state tests, such as water absorption and compressive strength, were evaluated. The state results indicate that the use of NaOH does not impair the workability properties of the material, while the compositions containing KOH indicate that the dissolution of this material is not as efficient in the cementitious medium in the first minutes after mixing the material. This impairs the workability of the mortar. In the hardened state, the results of water absorption and compressive strength showed the occurrence of alkaline activation of silica fume, due to the formation of tobermorite and zeolites. It is concluded that the use of hydroxides in conjunction with the pozzolanic material silica fume is a more efficient way of replacing Portland cement than the isolated use of pozzolana

Abstract:

Geopolymeric materials are understood to be formed by a precursor rich in aluminosilicate and low calcium content, activated by an alkaline solution. One of its main advantages is its production with less environmental impact, being seen, therefore, as a possible substitute for Portland cement. However, conventional activators are seen as a negative point, because they release harmful gases to the environment such as CO2. The coffee residue is seen with concern, since it is largely discarded in an irregular manner. However, it has a high potassium oxide content. Therefore, the objective of this work was to evaluate the mechanical performance in the hardened state of a solution activated metakaolin-based geopolymer material containing coffee residue ash. For this, the tests of compressive strength, bulk density and water absorption by absorption were performed. The mixtures with the use of coffee residue ash obtained compressive strength values very close to the reference mixture. The density test showed that the higher the residue content, the higher is its value. The water absorption, however, proved to be inversely proportional to the amount of waste, showing itself compatible with the density.

Abstract:

High-performance concrete emerged in the mid-1960s, and from there it began to be studied and adopted in several countries such as the USA, Norway, Canada, England, France and Japan. great economic and structural advantages are obtained with the use of high performance concrete (HPC), such as: reduction of the sections of the elements, low porosity and permeability, high resistance to wear and lower maintenance cost. The present work aims to develop a literature review on the main characteristics of high performance concrete and its use in order to generate savings in the amount of m³ of concrete used in the work and increase the useful area of projects from the reduction of the section cross of the pillars. The main differences between the usual concrete (up to 25 MPa) and high performance concrete are presented, in particular the selection of Portland cement, the selection of aggregates, the use of superplasticizers and the water/binder ratio. The high-performance concrete (HPC), for having a higher compressive strength than the usual concrete, allows the reduction of the cross section of the columns, resulting in an increase in the useful area, mainly in the first floors.

Abstract:

High-performance concrete (HPC) is considered to be a concrete in which its strength and durability are superior to that of traditional concrete. The HPC has characteristic compressive strength (fck) that starts from 40MPa and exceeds 100 MPa, the aforementioned characteristic is due to the addition of additives in its production and reduction of the water-cement factor, while the traditional concrete has a strength that varies from 25 MPa to 35 MPa. In the structural design, the fck of the concrete is considered, and through calculations it is mathematically observed that the higher the fck, the smaller the cross-sectional area of the steel used in pillars, beams, straps, among other elements, in addition, it is possible to observe that in a column that has a certain cross section, as well as beams and straps, if the characteristic compressive strength of the concrete is increased, the fck of the concrete that will be used, that is, the use of high performance concrete in the structure, the reinforcement ratio is maintained and the cross section of the column can be reduced, this situation reduces the weight of the structure, resulting in a lighter and less expensive structure.

Abstract:

Geopolymers have been the subject of recent research as alternative binders to conventional Portland cement. Its synthesis is summarized in the interaction of two parts: a dry one, called precursor and a liquid one, called alkaline activator solution. Among the various precursors that can be used, metakaolin is one of the most common and has already been produced and sold on an industrial scale. This work aims to study four types of metakaolin produced by the same company, in order to characterize the manufactured geopolymers and infer the inherent contribution to the type of metakaolin used making use of X-ray diffraction (DRX), laser granulometry, analysis chemistry and calorimetry. To evaluate the mechanical performance of the materials, specimens were made under equal conditions and then compressive strength tests were carried out. Based on the characterization and mechanical strength, it was found that the best geopolymers were obtained with metakaolin that had a lower SiO2/Al2O3 ratio, with a smaller average particle diameter and with greater total heat accumulated in the reaction, which allowed the samples to be reached strengths between 38 and 40 MPa at 28 days.

Abstract:

Cement is one of the most important materials for the construction industry. With its great demand, a problem generated is the excessive extraction of materials used in its manufacture and the environmental impacts generated by industries in the production stages. Given this, a product that could at least be produced with less environmental impact than Portland cement, but at the same time possessing its binding and mechanical properties would be economically and environmentally interesting. Considering this, the importance of studying geopolymers, materials rich in aluminosilicates with binding properties like that of Portland cement, is increasingly relevant. Geopolymers can become a green alternative to cement because its majority material can come from waste or tailings. In this work, the proposal is to present some of the precursors rich in aluminosilicates most studied by researchers today, showing promising results and opportunities for reuse of industrial waste often discarded by companies, harming the environment.

Abstract:

Sustainability is a widely discussed topic in civil construction, because this industry is one of the biggest polluters in CO2 emissions, which has aroused the need to seek more sustainable alternatives in relation to the environment. Thus, one of the advantages found in this industry is the ability to incorporate waste into its materials, resulting in reduced environmental impacts. In this scenario, this study evaluates the potential of treating natural fibers in coating mortars, checking the consistency index, mass density in the fresh state, incorporated air content and viscosity. The mixtures were prepared with 1.5% pineapple leaf fiber, superficially treated with tannic acid in proportions of 5 and 10%, in addition to the reference for comparative analysis. The mortars were prepared using the proportion 1:1:6:1.5 (cement: lime: sand: water) and, although they showed a reduction in workability, only one of them was outside the standards established by the norm. The other evaluated properties indicated a reduction, resulting in benefits, in comparison with the reference. Therefore, the feasibility of applying this treatment and incorporating fresh natural fiber into mortars is evident.

Abstract:

Agribusiness is one of the most polluting sectors and its residues result in negative effects on the environment. However, these residues can be reused, as is the case with pineapple leaf fibers, which can be processed as reinforcing materials in cementitious matrices. Thus, this study sought to analyze the physical and mechanical properties of coating mortars with pineapple leaf fibers after surface treatment with tannic acid, evaluating the mass density in the hardened state, tensile strength in flexion, compression and capillary absorption. In this context, three types of mortar were produced, without adding fiber (reference) and the others with 1.5% fiber content, treated with 5% and 10% acid. Mortars with additions showed a reduction in density in all compositions in the 28-day period and a decrease in capillary absorption in the highest percentage of treatment concentration. Although the strengths have decreased, an increase in tensile strength in flexion and compression was observed at later ages, with a higher concentration of tannic acid. These results show the need for further studies to understand the performance of these mortars, in order to make their application feasible.

Abstract:

The present study aims to evaluate the effect of varying the ratio between the resin and the hardener on the compression behavior of an epoxy system. Epoxy resin is a thermosetting polymer widely used in the composite materials industry due to its excellent mechanical, chemical, and adhesive properties. The parts per hundred parts of resin (phr) ratio is often used to specify the amount of hardener in relation to the resin in a given process, allowing for more precise and consistent results in composite material production. However, it is important to note that there is a limit to increasing the phr ratio, as an excessive amount of hardener may not result in an increase in the mechanical strength of the polymer. In this context, four formulations were produced, combining the epoxy system with organic and inorganic particulates. The tests were conducted according to ASTM D695. The results showed that reducing the phr ratio is possible and did not significantly affect the stiffness of the materials. However, in formulations with higher amounts of particulates, a greater demand for hardener was observed.

Abstract:

The polymer matrix reinforced with vegetable residues forms composites that, when compared to traditional materials, offer significant advantages such as biodegradability and low emission of polluting gases. The strategic use of natural residues, such as corn stalks, helps reduce environmental problems. This agricultural byproduct is typically discarded or burned after grain harvesting. The objective of this study is to develop low-cost, environmentally friendly polymeric composites by utilizing the aforementioned residue. In this regard, the density and morphology of corn stalks were characterized, along with investigating the influence of their incorporation on Izod impact resistance. Test specimens were fabricated with volumetric fractions of 0%, 10%, 20%, 30%, and 40% of the residue in a vegetable-based polyurethane matrix derived from castor oil. Through this study, the morphology and density of corn stalks were characterized, with the latter being measured at 0.18 g/cm³, significantly lower than other materials such as the composite matrix. However, the incorporation of this residue led to a decrease in impact resistance

Abstract:

Epoxy resin is a versatile polymer widely used due to its excellent mechanical, electrical, and chemical properties, as well as its use in the manufacture of composites. However, the presence of bubbles during the curing process is a common problem that can negatively affect its performance, especially in the production of composites. Therefore, various techniques have been developed to reduce the porosity of materials, such as the use of vacuum and additives. In this sense, this article discusses the influence of the use of an anti-bubble on the compression resistance of particulate epoxy matrix composites. The evaluated epoxy system was DGEBA/TETA and the anti-bubble additive used was Siladit 53. Four formulations were evaluated, including the pure epoxy system, with organic, inorganic, and hybrid particles. The tests were carried out according to ASTM D695 and their results were analyzed through an analysis of variance (ANOVA). Such analysis indicated that the use of anti-bubbles reduced the stiffness of the composites but did not significantly increase the resistance of the specimens.

Abstract:

The incorporation of natural materials as a reinforcing agent in polymer composites is an area of scientific research that has gained widespread recognition in the manufacturing of new products that promote a lower environmental impact. Due to its mechanical properties and availability, corn stalk is a waste material that has shown potential to reduce costs and increase the sustainability of the final product. Various industrial sectors, such as aerospace and automotive industries, have shown interest in exploring this material. Therefore, the objective of this study is to analyze the mechanical behavior of 100 random corn stalk fibers, calculate their density, and observe their microstructure. The fibers were subjected to tensile strength testing, the method used for density determination was pycnometer, and scanning electron microscopy (SEM) was conducted. As a result, a relatively low density and high strength were obtained as the fiber thickness was reduced, indicating the viability of using this material to produce high-performance and lightweight composites.

Abstract:

Environmental changes and innovative production methods have made advanced composite materials essential to modern societies. Fibers of natural origin have emerged as a promising alternative to synthetic fibers due to their excellent mechanical properties and advantageous cost-benefit ratio. The purpose of this study is to observe the structural behavior, in view of their mechanical properties, of composites from natural fibers and synthetic resins. The main relevance of this research is to obtain epoxy composites with selected ramie fiber reinforcement working as a new material for high performance bicycles and other purposes. Characterization of the ramie fibers, as received, was done by tensile test and density by pycnometry. The results show that the ramie fibers as received have the inverse characteristic compared to the natural behavior of natural fibers, because the larger the diameter is, the tendency of the ramie fibers of this batch is to increase, evidencing that the density of defects caused during the processing of the fibers remains independent of the diameter.

Abstract:

The use of ceramic waste in epoxy composites has been a good option for replacing materials generally already used in the current market. With performances similar to the usual particulate composites; analyzes and tests are being worked on in the scientific area so that it can be implemented in the commercial environment with the possibility of replacing the already usual ceramic particulate materials such as: alumina, silica, carbonates, etc. An industrial ceramic waste usually found in quarries is granite, which when added in particulate form in composite materials with epoxy matrix, tends to improve: mechanical properties, increase in density, resistance to abrasion and impact. The mechanical compression test according to the ASTM D695 standard, which brought results that helped in the development of knowledge about this material. Specimens of different percentage variations were made, up to 20% in volume, to compare the performance in comparison with pure resin (DGEBA/DETA) with the composite reinforced with granite particles. The results demonstrate that the incorporation of granite particles increases the compressive strength of the composites, showing great potential to be used as an engineering material.

Abstract:

This study is part of a research that aims to create a protocol for dating Brazilian concretes based on advanced techniques for the characterization of materials. A viability assessment of detecting plasticizer admixtures in Portland cement mortars using the Fourier Transform Infrared Spectroscopy (FTIR) is presented in this study. For this, analyses were carried out: (i) in admixtures based on lignosulfonate and polycarboxylate; (ii) in mortars produced without admixtures and with the two types specified; and (iii) in the sand used in the production of mortars. The results showed that these substances leave a “fingerprint” on the hardened mortar, and the FTIR technique proved to be suitable in detecting the presence of these products in cementitious matrices. FTIR, combined with other characterization techniques, can provide clues about the age of existing concretes and make it possible to correlate the presence of admixtures with the matrices' hydration and carbonation processes.

Abstract:

SiC particles with different sizes and shapes are separated into distinct granulometric fractions to ensure the quality of the final product. High-quality SiC is achieved when the granulometry is in the nanometer range. The efficiency of the classification process is critical to the quality of the final product, with the market value of SiC reaching US$3.3 billion in 2022, Brazil is one of the largest producers of raw SiC, but the country needs to import carbide in finer granulometries for industrial use. The aim of this study is to develop an efficient method for nanometric fractionation of silicon carbide powders. The results showed that it was possible to obtain SiC with a diameter below 2 μm and increase the efficiency of the process by up to 68%. Multiple chemical dispersants were tested for the centrifugation process to disaggregate the solution and increase the yield, with sodium carbonate standing out.

Abstract:

The use of personal protection is increasing due to the recent increase in violence, domestic and international conflicts. This fact drives research aimed at the production of new materials for ballistic applications, focusing on the use of natural lignocellulosic fibers (NFLs) in polymer matrix. In this context, the hybrid composites of flax and aramid fabrics stand out in ballistic applications such as reinforcements in low-density polyethylene (LDPE) matrix. For this, composites were produced in five different configurations: 19A0L, 17A8L, 12A12L, 8A17L and 0A27L. Residual velocity tests were performed to verify its preliminary ballistic behavior. The 17A8L composite is capable of containing all projectiles, while the 19A0L, 12A12L and 8A17L composites have Class IIIA protection, which is above the standard specification. For pure flax condition (0A27L), as expected, there was not a satisfactory result in terms of ballistic armor. In this way, the possibility of using these hybrid composite materials for the manufacture of ballistic helmets is highlighted.

Abstract:

The replacement of synthetic fibers by natural fibers has been the subject of intense research, especially when applied to composite materials. In this work, the combination of flax fibers with aramid was investigated as reinforcement for a low density polyethylene polymeric matrix. Hybrid composites prepared with different configurations are characterized by their resistance to Izod impact. The results obtained showed that the composite containing only flax (0A27L) presented the best results in terms of average energy of impact Izod compared to the other investigated composites.

Abstract:

The use of graphene has been increasing over the years since its discovery, so several other materials have been produced from it, such as reduced graphene oxide (rGO), which has excellent physicochemical properties. The use of the ultrasonic bath has been studied, in order to be used in the reduction of several particles, as well as those of rGO. Therefore, this work aims to evaluate how the use of the ultrasonic bath influences the reduction of rGO particles during certain times. The results indicated the efficiency of the sonication process, being directly proportional to the exposure time, obtaining a reduction of more than 93% of the particles during 12 hours, so the use of this method can be applied to obtain reduced rGO particles.

Abstract:

The aim of the present work was to characterize ENDUR300 alloy in comparison with UNS S41003 alloy in a saline medium at different temperatures. The work methodology was performed in the following steps: preparation of samples; performance of electrochemical tests of open circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy; and characterization of the surface of the alloys after the electrochemical tests by scanning electron microscopy (SEM). The electrochemical tests were performed with UNS S41003 and Endur300 alloys in 500 ppm NaCl medium at 25 °C, 50°C, and 80 °C. The results showed that the main corrosive process mechanism observed was localized corrosion in both alloys due to the presence of pits after the polarization tests. The increase of the medium temperature caused a reduction in the corrosion resistance of both alloys, being observed a smaller passive region in the 80 °C condition. In general, it was observed that there was no significant change in the corrosion resistance of ENDUR300 alloy and that the thermomechanical treatment caused only microstructural and mechanical properties changes without adverse effects on the corrosion resistance.

Abstract:

Cement composites reinforced with vegetable fibers have been gaining prominence in engineering, as these fibers provide these composites with some advantages, such as decreasing density, reducing fragmentation and cracking of concrete, improving its performance and durability. Coconut fiber is one of these plant fibers. Cementitious composites reinforced with coconut fiber show an improvement in the behavior when subjected to flexural tension. The fiber content of 0.8% in relation to the concrete volume showed a gain of 12.6% in flexural tensile strength when compared to conventional concrete and 1.7% for concrete reinforced with 0.1% fiber.

Abstract:

In this work, the rheology of iron ore slurries was investigated in a rotational rheometer. The deleterious effects of particle settling and Taylor's vortices, both recurrent in such devices when used for slurries consisting of coarse or dense particles, were identified. The rheological data were adjusted by Power Law and Tscheuschner models. The behavior indices (n) for the slurries at 36.8 and 43.6% solids by mass showed values of 1.535 and 1.493 respectively, indicating a shear thickening behavior. The results showed that for shear rates lower than 400s-1, the rheological curves overlap indicating the occurrence of particle settling. Furthermore, the flow conditions of the slurries were evaluated using the Taylor number, whose magnitude (Ta > 41.3) indicated the existence of vortices. The results showed that the rotational devices are not the most suitable for rheological studies of slurries with the aforementioned characteristics

Abstract:

The flour obtained from the mesocarp of babassu is a biopolymer produced on a large scale in the North and Northeast of Brazil for food purposes and has been showing favorable properties in biomedical and pharmacological applications. In this work, membranes based on this biopolymer were obtained and the effect of adding glycerol, a plasticizing agent, with concentrations of 20%, 40%, and 60% was evaluated concerning the wettability, morphology, and degree of hydration of the membranes. During the manipulation of the samples, it was observed an increase in the membrane’s flexibility when the glycerol was added. The results from scanning electron microscopy (SEM) show that the membranes processed using the 325 mesh had fewer particles than those processed with 200 mesh. Moreover, an increase in surface roughness was observed as the plasticizer was added. The hydration and wettability degree of the membranes decreased as the concentration of plasticizer increased; however, its hydrophilic profile was preserved. These results suggest that the characteristics of the membranes are interesting for application as wound dressings.

Abstract:

The following work aims to show a methodology and digital tools used during the planning stages of the Repairs of Suspension Systems of Converters from Ternium Brasil. The purpose was to optimize the downtime and assertiveness of the project. After measuring the Trunnion Ring, Suspension System and Vessel Shell by Laser Scanner, it was possible to generate a digital twins model, with the real deformations of the set and then carry out Time and Motion Studies, simulations of rigid body movement and structural analysis by FEA.

Abstract:

This paper reviews the literature on the use of biomass as a natural process for decarbonization of the steel industry, focusing on the Brazilian experience. Biomass, derived from sustainable forest plantations, is converted into biochar, bio-oil and biogas which are used as a renewable source of energy for iron and steel production. This process reduces net CO2 emissions, regenerates oxygen, and provides social and economic benefits for rural areas. The paper examines the environmental and representational aspects of biomass use in ironmaking and steelmaking, as well as the challenges and opportunities for its implementation and expansion. This also discusses the limitations of the current methodologies to assess CO2 emissions from biomass and suggests the need to consider oxygen depletion as a relevant factor. The article concludes that biomass is a viable and clean alternative for decarbonization of the steel industry and calls for more research and support from this sector for the development of the production and applications of biofuels.

Abstract:

Environmental concerns have become increasingly frequent, driving the development of alternative materials that use renewable resources. In this context, the composite materials of polymeric matrix with the use of vegetable fibers as reinforcement stand out. Vegetable fibers stand out for their abundance in nature, low cost, besides presenting satisfactory results when compared to synthetic fibers. Thus, it is possible to highlight the Guarumã (Ischnosiphon arouma), an abundant species of the Amazon region and widely used in the making of basketry handicrafts. Thus, this work aims to produce composites of polyester matrix, using Guarumã fibers as reinforcement. The process of making the composites began with the analysis of the fibers, the specimens were produced individually in a silicone mold with the incorporation of 10, 20 and 30% in volume of fibers. The tensile mechanical properties of the composites were evaluated according to ASTM D 638 guidelines. The results obtained revealed that the incorporation of Guaruma fibers in polyester matrix did not significantly change the values obtained in relation to pure resin, however, the Guaruma fiber shows great potential as reinforcement in composite materials

Abstract:

The purpose of this study was to evaluate the biocidal effect of the well-known disinfectant, peracetic acid (PAA), formula: CH3COOOH, in cooling water, in order to search alternatives to the use of chlorine (and its derivatives), which is corrosive and reacts with organic matter present in waters forming toxic byproducts. To achieve this goal, experiments using water samples taken from a basin of a chemical industry’s cooling tower were conducted following a factorial matrix. Experiments were performed using a commercial 15% w/w PAA solution. Aqueous concentrations of PAA were set at 1.0 mgL-1 and 2.0 mgL-1; at water’s pH values of 8.0 and 8.8. Each evaluated treatment condition was monitored for 5 days and total heterotrophic bacteria counts were made without biocide and after different contact times of the biocide in the water. The contact times were 5 min, and 1, 2 and 4 h per day, considering the application of the biocide in periods of 4 h per day. This methodology has allowed us to conclude that the two doses applied were efficient in controlling microorganisms depending on the water pH. Starting from a water with a natural microbial count of colony-forming units per milliliter (CFU/mL) of 106 to 107, the treatment led to a reduction in counts down to 102 CFU/mL. The results were 10 times more efficient under 2.0 mg/L of PAA in comparison with 1.0 mg/L. In addition, at set pH 8.0 the biocidal action was 10 times higher in comparison to pH 8.8 for the same PAA concentration.

Abstract:

Descaling of slabs exiting reheat furnaces prior to hot rolling is an important step to improve surface quality in the steelmaking process. An induction heating system with a controlled atmosphere that replicates the combustion atmosphere in a commercial slab reheat furnace was used to oxidize high Si, Mn, and medium C steels. High pressure water jet descaling was performed following scale formation using a laboratory setup that mimicked the industrial descaling process. Effects of nozzle impact factor (N/mm2) on scale removability for the different steels were investigated. The critical values of impact factor required for scale removal are discussed.

Abstract:

Abrasive cutting is the ideal cutting technology for upgrading existing rolling mills, espe¬cially for long products. An increased throughput and flexibility, a high degree of automa¬tion and an improved quality of the cut products are substantial advantages of abrasive cut-off machines. To produce value-added products, such as SBQ bars, the utilization of perfectly tuned, state-of-the-art abrasive cut-off machines is essential to achieve the required product quality. Based on different examples at several rolling mill modernizations and upgrades by installing a high-performance abrasive cut-off machine various challenges of these projects were successfully managed and the operational re¬sults achieved.

Abstract:

Herein, the applicability and performance of 22MnB5 steel sheets as protective masks over hot forging dies has been analyzed. Two masks were obtained following two different approaches; by heat treatment of flat sheets in cooling conditions similar to the process of hot stamping and hot stamping on the axial geometry of a cylindrical part. In both processes the sheets were austenitized at 1100° C for 7 min and to obtain bainite microstructure, they were maintained at temperatures higher than 700°C. The flat and axial masks have been subjected to 100 forging cycles for each geometry and positioned on the lower surface of hot forging dies. Surface integrity has been analyzed from microhardness profiles, roughness tests, thickness measurements, optical and electron microscopy. Wear mechanisms have been observed in both masks which was more expressive in the axial mask. Abrasive wear and plastic deformation have been actively observed in both masks; however, they have shown firmness for application as masks.

Abstract:

The hoods of the converters are responsible for the capturing and the primary cooling of the gas coming from the steel production process. Due to the high temperatures and high rates of heat transfer involved in this process, the equipment needs an adequate cooling to avoid overheating and/or corrosion that can lead to failures and the need for stoppages in the production process. The present work aims to introduce the methodology and results obtained after chemical cleaning and modification in the treatment of cooling water of ArcelorMittal Tubarão converter hoods. The previous treatment used an oxygen scavenger and was replaced by a nitrite-based program. The results showed that chemical cleaning was able to remove the oxide layer that was deposited on the pipes, without compromising its integrity. The use of nitrite favored the formation of a passivating layer, in addition to reducing corrosion rates by more than 75% and the iron concentration in the system by 40%. After the new chemical program, the ideal condition of the refrigeration process was reestablished, reducing failures, and increasing system reliability.

Abstract:

The continuous casting process aims to obtain slabs with high surface and internal quality. This happens by the controlled transformation of liquid steel into solid steel inside the machine. The solidification process begins in the mold with the formation of a solid steel shell, which, when leaving the mold, is supported by rollers until the liquid core solidifies completely, that normally happens in the horizontal part of the machine. For the solidified steel shell to resist the ferrostatic pressure and temperature of the liquid core at the mold exit, it is necessary that it has a minimum thickness. This safe thickness is related to a minimum heat flux in the mold that must be compatible with the casting speed to avoid shell breakage. Usiminas Ipatinga unit Breakout Detection System (BDS) received a new module that evaluates the compatibility of the heat flux with the process parameters. The most recurrent mold thermal reduction mechanism at Usiminas Ipatinga unit is associated with a deviation in the physical-chemical behavior of the slag film due to the presence of hydrogen content in liquid steel above the solid steel solubility. Therefore, the breakout prediction logic due to incompatible heat flux has the potential to eliminate one breakout occurrence per year due to this failure mode and indirectly indicate high levels of hydrogen in the steel.

Abstract:

Ladle nozzle clogging is a recurring problem in steel shops worldwide. This event may cause heat return to BOF, interruptions in the continuous casting sequence, decrease continuous casting speed, and remove the ladle from the production cycle, leading to productivity losses. The causes of clogging are generally associated with the deposition of non-metallic inclusions (NMI) on valve walls or the solidification of steel by low temperature. Several factors can affect the behavior of NMI during the process, from slag chemical composition, deoxidation, calcium treatment, and flotation time. Thus, based on an exploratory analysis of a database of industrial heats, this study aimed to determine which process parameters have the highest correlation with clogging events in steels treated in the CAS-OB route. Machine learning algorithms were used to select important variables and develop a model to classify clogging events. The model achieved a classification performance of 66% and was explained using the Shapley values method, which considered the influence of calcium content, valve life, desulfurizer weight and NMI removal mechanisms such as the use of argon lance and porous plug. Based on these results, it was possible to propose actions to reduce the incidence of ladle nozzle clogging

Abstract:

The civil construction industry has high global economic importance and is constantly expanding. Portland cement, the material most used on construction sites, has production processes that are harmful to the environment, emitting considerable amounts of greenhouse gases. As a sustainable alternative, geopolymer composites have been studied, with the addition of natural fibers as a reinforcement phase. This work aims to investigate composites of geopolymers with the addition of fibers from the leaves of the pineapple crown, generated in the economic activity of the municipality of São Francisco do Itabapoana-RJ, as agricultural waste, in order to point out a potential destination. An alkaline treatment of mercerization of the fibers was carried out, for a better interaction with the matrix. Compositions with 1.5% and 3.0% addition were prepared and the mechanical properties of resistance to flexion and compression were evaluated. Water absorption tests were carried out by immersion and an effective alkaline treatment was verified by means of SEM. According to the results and analysis of the specific strength, the mechanical properties evaluated were not compromised, reaching 14.2 MPa of compressive resistance with the addition of 4%. The results were positive, pointing to a possible, environmentally friendly destination for the waste generated.

Abstract:

This work aims to present the implementation of Coke Battery #4 at ArcelorMittal Tubarão, which aimed to bring gains in the environmental aspect with the implementation of new technologies that, in addition to providing less impact on the environment, increased the efficiency of production processes. Throughout this work, the main challenges faced during the implementation of the project, which mostly occurred during the pandemic, will be addressed, as well as the main solutions adopted and the excellent results for human safety. The main challenge was to build a new battery and integrate it into a plant already in operation.

Abstract:

The function of the limestone input in the pelletizing process to adjust the physical-chemical and metallurgical quality of the pellet first goes through the vertical roller milling process, where the necessary physical quality is acquired, the process is composed of a grinding plate, pairs of rollers that roll over it and the carcass with the static separator in its upper part. According to the operating time of the mill, a loss of efficiency is going expected, impacting productivity or the quality of ground limestone. It is necessary to monitor its indicators for a new setup vertical roller mill and thus ensure its quality and productivity level to meet demand.

Abstract:

In a mining activity, reducing the size of rocks is essential for the mineral treatment process, whether in the physical release of particles and size abilities or in increasing the contact surface for the use of reagents when necessary. Hence, the aim of the present work was to increase the performance of secondary and tertiary crushing in the Mineral Treatment Plant (ITM) Samambaia of Mineração Usiminas, increasing the use of the internal cover of the cone crushers. Its main goal was to reduce the rolling load, increasing the operating time of the internal cover through optimizing the crushing chambers level control logic. The results obtained with this work led to an increase of the feeding rate of the plant with a reduction of the percentage of rolling load, as well as the increase of the internal cover lining life of the cone crushers. It was also noted that there was even less maintenance downtimes to replace internal cover and therefore cost reduction.

Abstract:

Flotation kinetics refers to the amount of product or mineral to be floated as a function of the residence time elapsed in the process. Its objectives can extend from the definition of equipment sizing, optimization of operational parameters and consumption of reagents. The three basic mechanisms can influence the kinetics of the flotation process: (i) selective collision and attachment of particles to the air bubbles; (ii) shear resistance and particle transfer to the foam zone and (iii) resistance of the bubble-particle unit in the foam and transfer to the floated. Flotation collectors play an important role in various microprocesses involved in those mechanisms. Different kinetics have been observed through different technologies of collectors. Knowing the constant kinetics of the collectors can collaborate with several improvements in the process, such as: reduction of reagent consumption, higher recoveries or even a fewer number flotation stages, thus reducing CAPEX of the project and the OPEX of the operation. In this work, three ether-monoamines were studied in flotation kinetics tests using samples of friable itabirite and compact itabirite, in order to know their kinetic constants. Different dosages and stages of collector addition were investigated. Among the tested collectors Tomamine M-3513 seems to be the fastest collector for both ore samples.

Abstract:

In this work, a Machine Learning with Convolutional Neural Networks using Morphological Filters was modeled in a public dataset for Corrosion. 5 differents Convolutional Neural Network was tested and also 4 kind of Morphological Filters, in additional the test withouy any filter to compare. The results show a small improvement using morphological filters

Abstract:

This work focused on improving the reliability of the test results through the development of a laser marking system for recording Quick Response Code (QR Code) on specimens through the automatic recognition of samples for product certification tests at Usiminas' mechanical testing laboratory in Ipatinga. The marking was done manually, using industrial markers, which could allow the exchange of samples or specimens, approving unrepresentative tests, rework and decrease of service level agreement. The changes were both on sample receiving and preparing process and on manufacturing execution system (MES) from mechanical and metallographic testing laboratory (LEME). The positives results were traceability ensurement of samples and specimens, increase of productivity, automating and security of the process and, consequently, increase on reliability of tests results. The solution is innovative and scalable.

Abstract:

The technology known as Sequence Impulse Process (SIP) injects oxygen with high kinetic energy through the tuyeres on a regular basis. This method improves the local conditions within the raceway of the furnace and enhances its overall performance. In this paper, the principles and key components of this full-scale technology will be introduced, along with some impressive findings from operational results at the world's first blast furnace to use SIP technology, which is operated by thyssenkrupp Steel Europe AG at their Duisburg site in Germany. Previous reports have shown that the use of SIP technology results in a reduction of the total fuel rate and CO2 emissions, as well as enabling higher productivity and a stable use of increased PCI rates on the blast furnace. The current paper will focus on results from a period where low-quality raw materials were used and will provide new information about the performance of BF1 with SIP technology compared to the minimum fuel rate requirement and the performance of other blast furnaces at the same site during that period.

Abstract:

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Abstract:

Aiming in diminish the human impact on the environment scientist suggests the reinsertion of agricultural or industrial waste on the production chain among others solutions. In this scenario, this work aims to evaluate the potential use of the broom sorghum colm fibers as polymer composites reinforcement. These fibers have no known current use and are commonly discarded on the field after the harvest of the fibers from the panicle of this plant. For this study one hundred fibers were extracted from the plant colm and subjected to tensile test after is measures and weigh were taken. The density of these were also obtained by water picnometry. the results shown a surprisingly low density of around 0.3 g/cm3 with a god tensile strength that increases with the main diameter decrease.

Abstract:

Condition monitoring in rolling and finishing mills is state of the art, mainly based on vibration monitoring and evaluation of additional process and equipment data. In iron- and steelmaking condition-based maintenance is less popular. Due to much slower machines, methods of vibration monitoring are often missing, and only individual solutions for specific components, but no comprehensive system covering a whole plant, exist. Furthermore, traditional condition monitoring systems only provide warnings and alarms but no support in problem-solving. In this paper the main aspects of a comprehensive condition monitoring solution are presented using examples of ironmaking, steelmaking, and casting. It goes without saying that the mentioned principles are also valid for downstream process facilities.

Abstract:

This paper aims to present the planning, the technical and operational adjustments, in addition to the results obtained in the process of reducing the variation between objective basicity and actual basicity in Blast Furnace 2 at Aperam South America. The work was carried out in accordance with the Six Sigma methodology through the following steps: definition of the ideal basicity variation target for blast furnace operation, development of sampling processes and service in the raw materials laboratory, restructuring of control and formation of stacks, development of metallic charge suppliers and operational control during variations in basicity. Thus, for an objective of reducing the projected and real basicity variation of 30%, a reduction of 59.74% was achieved, which was maintained in the years 2021 and 2022, validating the methodology and the actions taken.

Abstract:

The objective of this work was to create a geopolymeric paste of metakaolin and residue from Porto do Açu (RPA), from the dredging process, to achieve structural reinforcement values. X-ray diffraction (XRD) and laser granulometry were performed to investigate the precursors. Subsequently, metakaolin-based geopolymers were prepared with RPA replacements in 8 compositions, varying the thermal cure time in 1, 3 and 6 days at 65 ºC and compression rupture in 7 and 28 days. The XRD of RPA showed a high crystallinity and low potential to act as a precursor, due to its low reactivity, resulting in compressive strength values below 1.65 MPA for 100% replacement of RPA. The granulometry showed that RPA has finer particles than metakaolin, being a good filling material. Thus, the compressive strength results showed that the replacements at lower levels, up to 30% of RPA, cured at 65 ºC for up to 6 days were effective and achieved strengths greater than 22 MPa, a fact that may be linked to the filling of voids in the samples due to the greater fineness of RPA compared to metakaolin.

Abstract:

Adding hydrogen, produced from renewable sources (H2-green), to existing natural gas pipelines is a useful short-term strategy to reduce industrial CO2 emissions. This approach allows for the wide distribution and application of hydrogen, accelerating the energy transition with a focus on decarbonization without major investments. The introduction of H2-Green in existing infrastructure requires careful analysis of gas interchangeability factors that, if not considered, can affect the performance of equipment connected to the natural gas network, as well as the safety of production processes. In this context, and in recognition of the potential of green H2 as a vector of industrial decarbonization, this work provides a review of the literature with an overview of the criteria used for the reliable standardization of interchangeability of fuel gases as well as the characteristics of the mixture of hydrogen and natural gas with focus on end-use application

Abstract:

Quality criteria in cold rolled sheets have been continuously increased due to a highly demanding and competitive marketplace. Driven by the Lean manufacturing movements and sustainable projetcs development, where the growing need for otimization of resourses, the steel sheet flatness effects plays an important role in meeting more robust quality requirements. Flatness is a requirement of cold rolled steel that guarante the final product aplicability. Futhermore, into finishing process, this feature is strongly attached to a good material performance during its processing, avoiding downtime and reducing scrap generation. Nonetheless, it’s presented a case into the flatness universe which motivated an investigation, due to a shape defect showed up as decentralized waves on metalic sheet. This events were correlated to work-roll assymmetry. It was shown throughout mathematic methods in MATLAB® software, how these assymmetries would reflect in rolling gap profile resulting in such flatness features. The analysis was embased comparing both, symmetric and assymmetric work-roll profile.

Abstract:

The strip guiding systemS serves to keep the strip, which shows tendency to run unevenly from the deflector rolls, in the centre of the line or in any other defined position. The strip guiding systemS thereby prevents damage to the product or the production plant and ensures that the strip runs evenly through the production process. The purpose of this paper is to present the principle of operation, characteristics, capacities, and the main types of strip guidance systems available for cold rolling lines.

Abstract:

Danieli's innovative approach to hot rolling, a critical step in the production of aluminum coils. Danieli's method integrates several technological packages, including a sophisticated thermal model that simulates temperature distribution, an invention called "Exstream Precooler" (Patent Pending) a cutting optimization system that minimizes the scraps, and a transfer bar temperature control system. The use of these technologies enables optimization of the rolling process parameters, resulting in improved product quality, increased productivity, reduced energy consumption, and minimized surface defects. These technological improvements are expected to bring consistent benefits to the user, as they provide a more efficient and accurate method for hot rolling.

Abstract:

The demand for higher steel grades has increased the need for improvements in the operation of production units and the implementation of automated processes, making viable functions essential for international steel producers. One critical aspect of achieving steel grade quality and reducing alloys is to prevent slag carry-over during secondary metallurgy processes. The automatic tapping procedure in BOF converters can significantly reduce slag carry-over, improve yield, reproducibility, working environment and safety, and minimize crew required. Historically, tapping in BOF has always been a manual function that heavily relies on operator expertise, making tapping time and quality dependent on their skills. However, the implementation of automatic tapping has shown that it can achieve shorter tapping time, low slag carryover, and improved yield. Therefore, implementing reliable measurements and automatic tapping in high-end steel plants can optimize production and enhance steel grade quality.

Abstract:

Multiple defects, such as slivers, laminations or surface inclusions, can occur during steel production causing losses from reduced quality and rejected production. The Cracs Preventer analyses data from the entire process chain with the goal of reducing losses due to those defects. It does so by combining metallurgical expertise with artificial intelligence. The defects are predicted before they occur and the necessary countermeasures to avoid the defects are suggested. The Cracs preventer can currently be applied to flat products and long products production.

Abstract:

Extremely low levels of sulfur in steel can only be achieved through secondary refining. Versatility and high productivity are sought, guaranteeing internal and surface quality of the steel, while keeping short treatment time and competitive costs. Physical and mathematical modeling are important tools used to improve the industrial operation, optimizing process parameters and finding the means of reducing sulfur levels in steel. The way the desulfurizing material is added significantly affects the desulfurization process. In this study, bottom tuyere reagent injection into the ladle was evaluated using a physical model and fluid dynamics simulation (CFD). The effect of the carrier gas flow rate on bubble size, velocity profile inside the ladle, and mixing time in a 215-ton ladle model at a scale of 1:8 were evaluated. The velocity profile was determined in two central plans of the ladle using the Particle Image Velocimetry (PIV) technique and the mixing time at two points using conductimetry technique. Good agreement was observed between the experimental results and the predictions obtained by CFD. Shorter mixing times are obtained when higher gas flow rates are applied, providing greater stirring energy to the system. In addition, the analysis of the trajectory of oil droplets that simulate the material injection into the ladle and the eye opening in the surface layer of slag suggest a strong influence of the flow rate on the material dispersion.

Abstract:

Most magnesia-chrome bricks, which are typically applied as relining material in various industrial furnaces, are fired bricks, roughly 90% of which are produced through a high temperature firing step in the case of our production plant. On the other hand, the fuel consumption of unfired magnesia-chrome bricks in the production process is approximately 1/9 that of fired bricks. Substitution of fired magnesia-chrome bricks with unfired products, therefore, directly contributes to reducing environmental impact. Historically, unfired magnesia-chrome bricks were commonly used as a metallic case combined with bricks that could be suspended from the ceiling of open hearth furnaces. Even today, they are produced in small quantities for limited applications such as copper smelting furnaces with a similar furnace structure. Taking into account the above-mentioned advantageous energy-saving aspect, new unfired magnesia-chrome bricks were developed by introducing several modern technologies for expanding its applications. With use in the lower vessel of RH vacuum degassers, as one of the potential applications, a series of laboratory evaluation tests were conducted. The newly developed unfired magnesia-chrome bricks exhibited an equivalent level of thermal spalling resistance as well as FeO corrosion resistance to that of currently used direct-bonded magnesia-chrome bricks.

Abstract:

Tar is a byproduct of the dry distillation of coal when producing coke for blast furnaces. Its generation occurs during the cooling of the coke oven gas and is definitively separated when passing through the downcomer. The condensed phase is directed to decanters via gravity to separate the tar from the ammoniacal liquor based on the difference in density. However, this natural separation does not meet the required moisture percentage for tar sales (<10%). Therefore, tar with high moisture content is directed to a centrifuge to meet this parameter. Nalco Water used its product Nalco 71700 to break the emulsion of ammoniacal liquor and tar, allowing for greater efficiency in the separation process, reducing or even eliminating the need for the centrifuge at times. A test was conducted at a Brazilian steel mill where the average moisture percentage of tar was 19.42% (2022). With the application, this moisture was reduced to 11.72% (average), a 40% reduction. This resulted in energy savings in the centrifuge and reduced man-hours, totaling approximately R$ 2,580,000.00, enabling the application and enhancing operational reliability for the unit

Abstract:

Iron ore pellets used in direct reduction reactors must receive the application of a solution on their surface to avoid sticking during the production process in the steel plants. There are several studies regarding the types of solute, its characteristics and the specific target consumption to obtain the optimal mixture for application in the pellets. Through the specific "standardized" consumption, sets points of the industrial plants defined to allow the proper addition of the solute to the solvent occurs. An important process variable should be checked is density. However, density as control variable is few disseminated in studies in the literature. This article aims to show the results obtained in the industrial tests considering the density as an additional control variable in the preparation of the solution for application of the coating in IRON ORE pellets.

Abstract:

The global mining industry faces surmounting technical and financial challenges, and with a growing push for environmental sustainability, it has become more important than ever for operations to mitigate risks and optimize operations to ensure maximum profitability and productivity over the life-of-mine (LOM). Hatch’s integrated efficiency solutions address difficult challenges to achieve high-end results. Holistic Mine-to-Mill optimization, as opposed to vain attempts to optimize unit operations in isolation, ensures interconnected processes operate at levels which provide the best overall efficiency. An initial comprehensive ore characterization program lays the groundwork for mechanistic drill and blast and comminution models, which provide short-term optimization opportunities for the whole operation. Sustaining the maximized operational efficiency that the Mine-to-Mill methodology delivers requires an appropriate throughput forecast model which predicts plant performance throughout the LOM. Hatch integrates mine planning, geological, and plant feed and equipment specifications into a geometallurgical model which forms the basis of proactive operating strategies. Lower grade deposits particularly can be benefitted by Hatch’s pre-concentration initiatives that promote an efficient use of resources. Removing coarse size waste in early mineral processing stages has the potential to increase production and reduce transport, processing, water, and energy costs. Technologies which provide such benefits to operations include pre-screening, bulk ore sorting, gravity and magnetic separation, and coarse particle flotation. This paper provides an overview of the aforementioned optimization strategies’ methods, potential benefits, challenges and case studies with actual results

Abstract:

Like frothers and collectors, depressants play a decisive role in the performance of cationic quartz flotation, also called Reverse Cationic Flotation of Iron Ore (RCFIO). Being structurally similar in terms of amylose (20-30%) and amylopectin (70-80%) content, the difference in performance between unmodified starches in hematite depression and in the flotation process as a whole is subtle and sometimes inverse, i.e. , for certain ores, corn starch is more efficient than cassava starch and vice versa. The final evaluation becomes more evident when applied and compared in a real industrial process, considering its operational peculiarities, and supported by statistical tools for an appropriate context. In this article, the differences between corn and cassava starches, used in a concentrator, were evaluated, restricted in terms of the low quality of the processed iron ore and the high final quality of the required pellet feed. The results showed that the use of cassava starch improved the productivity of the concentrator through higher production capacity, associated with better concentrate quality (lower %SiO2), and lower specific collector consumption, ensuring a better cost-benefit of the reagent system.

Abstract:

The implementation of state-of-the-art control systems solutions in material handling equipment in the Iron and Steel Industry is challenging due to the harsh environment, safety and availability requirements in the industry. Logistics and safety applications by indirectly measuring the position of the equipment used for material handling (cranes, trucks, forklifts, etc.) have gained a lot of momentum in the recent years. New technologies for position measurement able to work and survive in the long term within Iron and Steel facilities have greatly contributed to this trend. Benefits like production volume increase, better quality assurance, reduction of rejected material, reduction of costs associated with searching material throughout a yard or warehouse, which in the past used to be just wishes, are now a reality. This paper will present several cases where the implementation of position measurement systems have allowed obtaining additional benefits or side effects which help to compose a blend of benefits in addition to the original purpose which justified the original investment. Specific examples of actual implementation and the problems typically found during the implementation and the solutions will be discussed.

Abstract:

The objective of this project is to reduce CO2 emissions and energy consumption through hot charging, improving coordinated/synchronized between continuous casting and hot strip mill (LTQ), at the line sequencing level, seeking to increase the productivity of the Hot Strip Mill at ArcelorMittal Tubarão, in line with the drivers to increase production at the Hot Strip Mill, by changing the sequencing process of the Hot Strip Mill with optimization of the slab reallocation process (reduction of time and movements in the LTQ yard) during and after the formation of the sequência/Line-up of lamination with a focus on the temperature of slabs reheating furnaces. The work began with a review of metallurgical rules for reallocating materials, mapping processes (As Is), reviewing the objective function and constraints of the mathematical model for optimizing LTQ sequencing, opportunistic evaluation using Virtual Slabs( slabs still not produced, but already planned to be casted). With implementation of the process/system it is expected to achieve a potential increase in temperature slabs reheating furnaces, 10% reduction in fuel consumption in the furnace (relative to the material that is hot relocated), a 10% reduction in CO2 emissions, an increase in metallic yield, a reduction in lead time, a reduction the risk of material breaking during reheating (important for new generation AHSS steels, in addition to the increase in annual production of 40kt at the Hot Strip Mill at ArcelorMittal Tubarão

Abstract:

The Service Life Extension (SLE) project, started in 2013, is a strategy adopted by ArcelorMittal Monlevade, with the goal of extending the Blast Furnace A campaign through careful actions, with emphasis on: critical equipment for the operation, planning and execution of their repair, monitoring and temporary inspections in different components, implementation of new equipment and instrumentation, aiming greater control and operational robustness, among others. The start-up of Blast Furnace A took place in 1999, with a 15-years planned initial campaign. Currently, its complete repair is scheduled for 2027, when it will total 28 years of operation. Among the main justifications for this result are: Rigorous raw materials quality control, culture of operational excellence and process control, proper maintenance of equipment and implementation of the SLE project. The creation of the SLE has so far brought significant gains for the steelmaker by: Postponing the complete repair of Blast Furnace A, increasing control and monitoring of the main equipment, generating greater personnel and operational safety, avoiding unscheduled downtime, which impacts positively on operational stability and consequently on the hot metal cost of production and quality, thus improving the company's efficiency, productivity, and competitiveness.

Abstract:

Acrylonitrile Butadiene Styrene (ABS) is one of the most common materials in 3D printing, this polymer supports high temperatures, and its greatest advantage is due to its high availability and relatively low cost for 3D printing. The objective of the study is to analyze the mechanical properties between the SLA (using a photo-polymeric resin) and FDM processes (using ABS) through the tensile method, shore D, and IZOD hardness. Results showed an average elastic modulus of 482 Mpa for SLA and 114 0Mpa for FDM. The impact strength was 1.7 kJ/m² for SLA and 7.7 kJ/m² for FDM. Shore D hardness was 75 in both. It was concluded that ABS has the same hardness in both manufacturing methods, but the FDM process results in significantly higher impact and tensile strength compared to SLA

Abstract:

Asset Performance Management is an area that can be greatly improved with the adoption of digital solutions. One of the most relevant challenges for mining and metals operators continues to be equipment failures and the subsequent repair costs and production losses. New digital technologies can elevate preventive maintenance processes to unprecedented heights. Artificial intelligence, digital twins and computing resources are increasingly accessible and widespread. Although Predictive Analytics technology has been available for some years and has been used with great success by some companies, many other companies are still unaware of or have difficulty incorporating Predictive Analytics into their Asset Performance Management programs. The objective of this article is to present basic concepts, propose good practices for adopting Predictive Analytics of technology and exemplify how mining and metals companies are obtaining value from these solutions.

Abstract:

This work aims to show the equivalence of reduction in iron ore consumption in the sintering of ArcelorMittal do Pecém with the use of ferrous waste via a mixing plant that has the role of transporting, benefiting all the characteristic wastes of recirculation approved for consumption internal. The processing plant project was created to meet 3 sustainable pillars (environment, quality and cost). Since then, the sintering plant at ArcelorMittal Pecém, at the beginning of its operations in 2016 until 2023, has already consumed more than 1.5 million tons of processed residues that were generated at the plant and which, after being mixed, are called By-product, “mixture made up of all waste”. In the operation of the processing plant, procedures were developed to improve processing to ensure full consumption of all waste according to its generation, that is, a philosophy of consumption equal to what is generated in the plant without the need to dispose of it in landfills and collapse the system due to lack of By-product for sintering. With the integration processes between the beneficiation plant and the sinter mixing line, it is possible to correct demands in the By-product consumption, aiming at the best quality of the sinter product, since the sinter mass balance includes the theoretical calculation of the By-product quality, which in turn within the crude sinter production process, needs corrections in its absence or increase in waste consumption. With the use of residues systematically and constantly mixed through the processing plant of the supplier Phoenix do Pecem, it is possible to achieve an average reduction of 32 kg/tons for the production of raw sinter. Calculation base with the mass balance of Mar/23 of the sintering at ArcelorMittal Pecém. The beneficiation plant has a robust system of processing in the systemic mixture with load weighing scale and conveyor belts that is managed by the supplier Phoenix do Pecém, which send the residues for sintering. The nominal capacity of the plant is 100 t/hour. The process requires the use of water with concentrations of 8% for the purpose of agglomeration and mitigation of fugitive emissions on conveyor belts. All dosing scales have a system integrated with the mixer to ensure that the mixture has a By-product formation capacity equal to the specific projection of the sintering technical management.

Abstract:

Proper management of material resources is one of the biggest challenges facing humanity. This has relied on the use of waste to create new materials, which reduces the amount of waste deposited in landfills and the demand for material resources. However, the presence of moisture in the waste can affect the performance of composites. The objective of this work is to evaluate the influence of particle moisture on the compressive strength of polymer matrix composites. In this work, the matrix used was an epoxy system and the dispersed phase was chamotte and/or coconut shell powder. The formulations were evaluated in two configurations, using particles with and without oven drying. The compression test results from this work, through variance analysis, did not indicate a significant variation in the stiffness and strength of the materials, although greater porosity was observed in the test samples using particles that had their moisture removed. However, the manufacture of larger test samples may result in a greater influence of moisture on the creation of defects and consequently on mechanical properties.

Abstract:

The ArcelorMittal Pecém cogeneration Power Plant is responsible for producing process steam and electricity used in steel production, using the steel gases supplied by the process as fuel. With the capacity to produce enough electricity to supply the plant and sell the surplus, there is always a search for the maximum use of steel fuels to increase the levels of generation of electricity produced. By identifying the BFG blast furnace gas burning scenario in the flare due to design limitations for burning BFG and COG in burners, which allowed the burning of one or another of these fuels, this work was carried out to optimization the burning of BFG gas simultaneously with COG gas, ensuring the reliability of the boiler burners, minimizing BFG in flare, increasing the generation and promoting financial gain in the operation of the AMP Power Plant.

Abstract:

Standard roll printing technologies are no longer able to satisfy the requirements of the pre-painted coil business and comply with the more and more sophisticated market demands coming from the architectural/building and white goods industries. Digital printing technology, with its higher printing resolution and production flexibility is the state-of-the-art answer to meet these new requirements. The Danieli Digital Printing Solution also provides the possibility for bespoken limited production lots, guaranteeing the more frequent need of on-demand printing that standard roll printing technologies cannot satisfy. Danieli, thanks to a joint venture with Helios Kansai, provides the market with a complete solution for digital printing that overcomes the limits of other digital printing technologies.

Abstract:

Realistic material simulation is becoming increasingly important in the mapping of forming processes. The more accurate the material data and models are, the better the match between the simulation and the results of the production process will be. Thus, AI methods are also increasingly used in material simulation, which leads to further improvement of the simulation results. The paper demonstrates the use of AI in the form of neural networks for the simulation of phase transformation processes in steels during cooling from the forming heat. In this context, new possibilities arise compared to the usual use of CCT diagrams: On the one hand, the influence of changes in chemical analysis and austenitization condition can be gleaned. On the other hand, temperature-time histories with variable cooling rates can be better understood. The results significantly improve the representation of the forming process in simulation programs. Two application examples show the influence on the development of microstructures in long products.

Abstract:

Induction technology is a compact, clean, easily controllable and reproducible heating technology up to very high application temperatures with small space requirements. Nevertheless, conventional furnace concepts with fossil fuels are always used when a high geometric variety of workpieces has to be heated. Unless high process dynamics and smooth operation are required, lower primary energy consumptions and reduced CO2-emissions may be of interest. This article shows how the two often competing concepts can be advantageously combined to create an overall process that allows significant energy and cost savings. In hybrid heating, the induction is operated in the high temperature range.

Abstract:

For the development of the computational fluid dynamic (CFD) simulation of the ladle desulphurization process with reagent injection through a submerged lance, the calibration of interphase forces is essential to obtain a reliable prediction, which allows the distribution of gas and reactant particles throughout the domain to be known. In this work, using numerical simulations via CFX, the effect of lift, and turbulent dispersion forces in a 1:7 scale physical model of a 245ton industrial ladle was investigated. The distribution of gas predicted via CFD was assessed and validated with physical modeling results. The best combination of interphase forces was found by taking in account a virtual mass coefficient of 0.3, the turbulent dispersion force and a lift coefficient of 0.5. Mixing time was well predicted by the CFD simulations. The gas flow showed a great influence on the mixing time and off-centering the lance also reduced the mixing time.

Abstract:

A novel electromagnetic stirring technology (EMS) is introduced into a four-strand billet caster tundish. The purpose is to increase mixing zone volume and average flow speed, and eliminate dead zones, while the melt surface speed is kept low to avoid slag entrapment. From a metallurgical perspective, strand temperature is homogenized, inclusion aggregation and removal are improved, and the number of sequence casting heats increased. Water modeling was carried out to investigate the flow characteristics, as well as numerical simulation on both fluid flow and inclusion behavior. Pilot testing was carried out at Zenith Steel Co. Ltd, China. The results show that this technology is particularly useful for improving temperature stabilization and steel cleanliness in multi-strand billet caster tundish.

Abstract:

Manganese alloys are produced by reducing manganese ores in electric reduction furnaces. The electric reduction furnace is a device that uses electricity as an energy source to heat and melt the load and the reducing agent. In this type of furnace, electrical energy is supplied by electrodes inserted into the furnace. In addition to the influence of furnace geometry on its performance, several control parameters are important to ensure good production rates. The present work aimed to evaluate the increase in productivity of an electric furnace to produce manganese alloys after reforming and redefinition of some furnace parameters, changing its dimensioning, in order to obtain a greater productivity. The result of this project shows a productivity improvement of 33%, demonstrating the importance of the oven's geometric parameters in its performance.

Abstract:

In the study of nanoparticles in the area of biomedicine, more specifically to combat cancer, in many cases, it becomes necessary to search for small particle sizes and low values of saturation magnetization and magnetocrystalline anisotropy. In this work, we synthesized, using the sol-gel/combustion method, five mixed cubic manganese and zinc ferrites doped with different percentages of cerium. In the reaction, we used citric acid as fuel. The samples were characterized by X-ray diffraction, magnetization, and ferromagnetic resonance. The results showed that the ferrite with 3% Ce had the best values of magnetization and anisotropy for biomedical applications such as the treatment of cancer.

Abstract:

TODAY, THERE ARE MANY OPERATING COKE OVEN BATTERIES WORLDWIDE WITH A LIFETIME OF MORE THAN 40 YEARS. WHEN THE END OF LIFETIME IS UNAVOIDABLE, EARLY PREPARATION FOR A PAD-UP PROJECT SHALL BE STARTED IN ORDER TO CONTROL THE CAPEX. IN THE LAST DECADES, PAUL WURTH HAS EXECUTED A NUMBER OF PAD-UP PROJECTS FOR TOP AND STAMP CHARGED BATTERIES WORLDWIDE. THEREFORE, IN THE FOLLOWING PAPER WE WOULD LIKE TO GIVE YOU AN OUTLINE OF OUR APPROACH AND RELEVANT TECHNICAL SOLUTION.

Abstract:

Advances in mathematical modeling of HPGRs achieved a prominent position in the minerals industry in the last thirty years. Even though these modeling approaches have been used worldwide for improving HGPR operation for several different applications, their use is still limited to the description of steady-state operation, being unable to capture real-time process variability. The present work takes advantage on recent advances in HPGR phenomenological modeling to use it as a pseudo-dynamic approach describing an industrial HPGR pressing iron ore concentrates coupled with real-time information. Model is validated by capturing real-time variabilities in operating conditions to predict HPGR power, throughput and product Blaine specific surface area (BSA) along a period of twenty four months of operation. Investigation of the model as an online digital assistant showed potential scenarios to reduce the variability of the HPGR product BSA and increase the process efficiency in 19.2%, besides demonstrating feasibility to transfer work from ball milling (upstream process) to the HPGR.

Abstract:

Important advances and developments have been made in the last decade in the mathematical modeling of the high-pressure grinding rolls. However, performance prediction considering design variables, such as different roller geometries, or roller wear conditions, is still an engineering challenge. The simulation using DEM coupled to the multibody dynamics (MBD) in the movable roller is shown to be a viable alternative in understanding this operation. However, few studies demonstrate its validity. In the present work, the methodology proposed by the research group was used to assess the effect of using spring-loaded cheek plates, a novel development in the technology. The results open the black box of this technology, showing the potential improvements that could be reached with the application of the spring into the cheek plate. According to the simulation, the spring-loaded cheek plate contains the material between the rollers even with severe wear included in the confinement system, besides increase power and the reduction particle size.

Abstract:

This article presents a technological characterization and a statistical study on the influence of minerals with different textural types, such as martitic, specular and granular, on the performance of inverse cationic flotation to concentrate them. This study was carried out due to the need to understand the reason for the variation in the behavior of column flotation on an industrial scale. After the analysis, it can be proved that the specular hematite, due to its lamellar textural type, directly influences its floatability, even when dealing with an iron oxide it becomes floatable. Negatively influencing flotation, decreasing its mass recovery and increasing the iron content in the tailings

Abstract:

A Vale está mudando a forma de atuar em três temas interligados: segurança e gestão de riscos, gestão e organização de ativos, processos e cultura. Assim, o projeto desenvolvido com a Siemens, de Maintenance Digital Twin está alinhado com estes três pilares, uma vez que as diferentes fases deste projeto estão apoiando a Vale nestes desafios, além disso, hoje, a arquitetura do Digital Twin da Vale também permite redução de custos no processo de manutenção, melhorar a segurança e a excelência operacional e também reduzir o tempo de parada para manutenção. Na evolução deste projeto, com a implantação do xDT além de atingir a excelência operacional o projeto poderá prever falhas visando melhorar a segurança e o processo de manutenção.

Abstract:

The MES manual allocation process used to rely on excel spreadsheets, so the user was able to check only 10% of the slab inventory, as well as 10% of the order book at each execution. The new system allows searching 100% of the inventory and order book, substantially increasing the possibilities of allocation in “prime” orders. Besides that, operations that were performed manually by humans, such as order book overweight analysis, has become automatic, increasing the productivity of the entire process, reducing inventories, increasing OTIF, among others.

Abstract:

Ternium Brasil Blast Furnaces had their Blow-in in 2010, starting a stage in which Brazil received one of its newest integrated plants, being a milestone in the optimization and installed capacity (5 million tons per year). A regularity regarding the availability of equipment as well as process/operational strategies tends to guarantee a satisfactory result regarding the production continuity and fuel consumption in the AltosFurnaces that need to demonstrate the optimal connection between performance and cost savings. This work shows the evolution of controls and operational practices of the Ternium Brasil Blast Furnaces that allowed the improvement in results

Abstract:

The umbilical cables of oil platforms are a set of hoses and electro-hydraulic cables responsible for connecting energy, data, fluids, chemicals and monitoring operational parameters. As they are submerged in the sea, they are susceptible to compression. Thus, the objective of this paper is to analyze the impact of different fabrics when subjected to compression efforts, in order to find solutions for failures in umbilical cables when installing them on oil platforms. Several specimens were made with different types of weaves and were subjected to compression efforts by means of a hydraulic press, using microscopic analysis to understand the behavior of aramid fibers. It was possible to verify that the use of three-dimensional plots presented better results in the studied conditions when compared to flat plots. The main reason for the better performance is the greater ability of three-dimensional fabrics to dissipate tensions in space and their greater structural mobility

Abstract:

Overhead cranes with electromagnet lifting systems are widely used in different industries. However, it is essential that these equipment be operated safely and following the proper procedures. Preventive maintenance is critical to ensure operational performance and avoid possible system failures. To ensure operational safety, it is necessary to implement a robust protection system. Analytical tools such as Pareto charts and graphs can be used to identify which overhead cranes and sub-equipment have the most critical and frequent problems. This article presents the analysis and implementation of protection systems for overhead cranes. The systems of radar mounted between the cranes that assist operators to avoid collisions between cranes working simultaneously in the same hall will be addressed. Additionally, improvements in the lifting and electrical systems, such as the replacement of support shackles for electromagnets, identified through laboratory studies, and adjustments to wear component maintenance plans obtained through FMEA analysis, will be discussed. The results obtained were consistent, reducing system failures and ensuring plant reliability and the safety of operators and transported materials. It is concluded that the adoption of preventive measures and the use of analytical tools are fundamental to ensuring operational safety and efficiency of material handling equipment in different industries

Abstract:

This article reports the project of the use of DustControl technology in unpaved roads. The objective of the application was to minimize the emission of suspended particles in the atmosphere in the region of the Coal Yard and consequently reduce the risk to Health and Environment. To this end, wetting tests of the pathways were performed with application only with water and with the use of the chemical HaulageDCLA. After the analysis of the indicators, it was evidenced that the wetting of the roads with the use of DustControl Technology reduced by 3.6 times the number of trips of the truck in relation to the wetting only with water.

Abstract:

In order to reduce the use of raw materials and also reuse the sediments from port dredging, this research aims to partially replace the hydrated lime present in the production of mortars for coating walls and laying blocks by Dredging Waste Port of Açu (RPA). Replacements were made at 10, 20 and 30% by weight. The properties of the mortar in the fresh state were analyzed, such as consistency, mass density, incorporated air content and water retention. The replacements have properties similar to those of the reference mortar, making it possible to use the highest percentage studied in this research for application in the civil construction industry.

Abstract:

This paper presents a detailed case study of two photovoltaic systems, one fixed and one mobile, each with twenty photovoltaic modules, aimed at analyzing the factors that influence the electricity generation in these two types of systems. This will provide an overview of the proposed systems' efficiency and practical possibilities. To achieve the research objectives, a simulation of both models was performed using the PVsyst software. PVsyst has an extensive database, enabling designers to import meteorological data and utilize information from various sources. It also allows for simulating grid-connected, standalone, or pumping systems and provides detailed simulation reports, including scaling up to an hourly basis. The simulation results showed that the efficiency gain of a solar tracker can reach up to 24.7% during the day and an additional 28.1% per year compared to a fixed system. And the average annual yield performance is 80.6% for the tracking system, compared to a fixed-axis system which was 78.6%.

Abstract:

Actual market, specifically the automotive industry, demand day after day better quality and mechanical properties of the steel strips, as ductility and strength. With these requirements, there is a growing demand for AHSS steels that presents high levels of alloying elements, requiring new technologies to process this type of material in the Processing Lines. One of the main developments in recent years to process this type of material on the Processing Lines is the Furnace Rolls coatings, using the thermal spray method, promoting longer life and better surface quality in these rolls. However, after a certain operation time inside the furnace, conventional coatings chemically interact with high strength steels alloying elements generating defects on the roll surface and consequently on the processed strips.Focused on avoiding strip quality problems and also monitoring the condition of furnace rolls surface, SMS Brazil periodically performs a technical and precise inspection of all furnace rolls at customer's site, providing a preventive maintenance plan in a clear manner and promoting reliability gain of the product and the production process. Thus, through a complete final report, SMS guides the customer on decision making by pointing out predictions of when the rolls should be replaced or repaired and what coatings solution can be applied to prolong the Rolls life

Abstract:

Danieli FATA Hunter, a division of Danieli Group, has developed a new curing oven design (patent pending) for the coil coating industry. The new design introduces several advantages and benefits compared to the standard oven solution: a reduction in erection costs, times and risks, improvements of the fans lifetime as well as an improvement of the energy consumption performances. Several recent installations are demonstrating that this new curing ovens solution is the benchmark for highly demanding coated coils producers

Abstract:

In integrated steel plants, large quantities of blast furnace gas (BFG) with a lower heating value of 3.1-3.3 MJ/Nm3 are available. Due to high nitrogen content, an efficient use of pure BFG in high temperature processes represents a technological challenge especially for reheating processes in hot rolling mills. In order to overcome the issues of BFG utilization as a fuel in large reheating furnaces, Tenova has developed a double regenerative burner technology. The development of Tenova TRGD burners was conducted through Tenova’s typical R&D approach. Using computational fluid dynamics (CFD) modelling the burner design was optimized, while laboratory tests allowed to validate the prototype phase. Long term industrial pilot tests were carried out to validate the final burner design. By means of preheating BFG with the waste heat content from the flue gases stream, the typical operating temperatures of reheating furnaces (1350 °C) can be achieved without any fuel enrichment.

Abstract:

IN THE LIGHT OF THE INDUSTRY 4.0, THE ROBOTIC PROCESS AUTOMATION (RPA) IS BEING CONSIDERED AS NEW WAVE OF THE FUTURE TECHNOLOGIES, CONNECTING SEVERAL FIELDS OF ENGINEERING AS MECHANICAL, ELECTRONIC AND AUTOMATION. FOLLOWING THIS TREND, THE HUMAN PROCESSES IN THE STEELMAKING PLANTS, WHOSE LEVEL OF DANGER IS ONE OF THE HIGHEST IN THE INDUSTRIAL SECTOR, ARE BEGINNING TO BE ORIENTED TOWARDS BEING AUTOMATED. THE MAIN ADVANTAGES IN THE USE OF ROBOT MANIPULATORS IN THIS INDUSTRY ARE THE INCREASE IN THE SAFETY OF THE OPERATORS, IN THE QUALITY OF THE PROCESS AND IN THE PRODUCTION. HOWEVER, THE IMPLEMENTATION OF ROBOT MANIPULATORS IN THE STEEL INDUSTRY HAS SEVERAL CHALLENGES THAT RESULT IN THE LOW RATE OF USE OF THIS SYSTEM IN THIS SEGMENT OF THE INDUSTRY, AS AN EXAMPLE, EXPOSURE TO HIGH TEMPERATURES, HIGH CONCENTRATION OF DUST AND PARTICULATES AND ADAPTATION TO THE ORIGINAL LAYOUT OF THE MACHINE, WHOSE SYSTEM WILL INTERACT. IT'S SHOWN THE INCREASE OF PRODUCTIVITY, SAFETY AND PRODUCT QUALITY OF ROBOTIZED TUNDISH OPERATIONS IN CONTINUOUS CASTER OPERATION1. THE OBJECTIVE OF THIS PAPER IS TO PRESENT THE IMPLEMENTATION AND THE RESULTS OF THE ROBOTIZED TUNDISH OPERATIONS FOCUSED ON THE LADLE EXCHANGE OPERATION, IN WHICH IT IS NOTABLY THE MOST CRITICAL MOMENT OF THE CONTINUOUS CASTING.

Abstract:

Every year, industries, especially automotive, aeronautics, metallurgy, and civil construction, face losses generated by the oxidation process. This problem generates a financial loss of products, machinery, etc. The lead metallurgy industries face problems of tin oxidation caused by the addition of this metal in the alloy. This fact causes a significant financial loss, given that tin is used for this procedure and its current cost is (R$ 135,625.00 per ton). In the present work, a case study of this problem was carried out in a lead metallurgical industry of Acumuladores Moura S/A. To find the root cause, the PDCA analysis tool (Plan, Do, Check, Act) was used, following the philosophy of continuous improvement (Kaizen). For the analysis of the metal, a solid spectrophotometer was used to observe the concentrations of metals in the alloys. An experimental design of tin addition forms was planned, aiming at the influences of the addition form, mechanical agitation and temperature on the oxidation losses during the process. With the support of the industrial production, it was possible to do the experiments. With this, it was possible to conclude which the most efficient way to add tin is the one with the shortest mechanical agitation time.

Abstract:

In this work, a ceramic composite based on hydroxyapatite (HA) and bioglass (BG) was produced, aiming to verify the influence of the latter on the sinterability of HA. For this, the fraction of 4% by weight of this bioglass was chosen as an additive to hydroxyapatite, at two distinct sintering temperatures, with reference to pure HA. The materials were characterized by scanning electron microscopy (SEM) for morphological analysis, X-ray diffraction (XRD) to determine the phases formed and by energy dispersion spectroscopy (EDS) for a qualitative analysis of the chemical composition of the samples after sintering. In addition, for a better study of the effect of this addition on sinterability, the materials were evaluated for densification. The results show a decrease in porosity, but also a decrease in the density due to the decomposition of hydroxyapatite in whitlockite phases, at the same sintering temperature, when bioglass is added.

Abstract:

Anhydrous ammonia has high toxicity (tolerability ≤ 20 ppm) and flammability, and is generally transported on ships, trains, tank trucks, and pipelines. It is raw material to produce fertilizers and an effective coolant used in industry. Supplied in liquefied form, vaporizes immediately at atmospheric pressure forming a floating cloud. At Usiminas Steel plant, in Ipatinga city, anhydrous ammonia is generated as a subproduct of the metallurgical coke manufacturing process and is stored in pressurized liquefied form (15 bar) in seven tanks of 123 m³ each. An automatic ammonia neutralization system, with a 5 s response time, was developed and built in the storage tank and truck loading area to neutralize 100% of the worst scenario of leakage (7,668 kg/h – 12 m³/h). Thus, ensuring safety and low risk for the industrial plant. Ammonia leak neutralization tests were carried out to demonstrate the spray nozzle efficiency.

Abstract:

During the iron ore beneficiation process, ultrafine tailings are generated, which it has a chemical composition (typically 35% Fe) and very fine granulometry, which are discarded in piles of tailings or dams. In this way, the use of this product generates a sustainable appeal, mainly in the “in natura” condition, where the entire product can be used without the generation of secondary tailings or investments in ore concentration equipment. Depending on the application, there may be a requirement for high concentration material (typically with 60% Fe) two Fe contents will be studied in this article. Thus, the focus of this work is the production of agglomerates for use in electric arc furnaces, since the cold agglomeration process is also aimed at products with low mechanical compressive strengths, resulting in a lower environmental impact for the product due to low emissions of CO2 and also a lower cost than pelletizing process. Thus, the objective of this work was to produce iron ore agglomerates from the ultrafine, using cement as a binder. The study compared two agglomeration processes (briquetting and extrusion), and different amounts of cement and iron content. The best process was extrusion, requiring 8% of cement and reaching 299.9Kgf of compressive strength for high Fe concentration agglomerate.

Abstract:

Reliable data is essential for metallurgical production accounting. However, in large production chains, it is common to have material flows or stocks not measured properly, or even that are unknown, causing an inaccurate indication in the mass balance. This work presents the requirements for a tool compatible with the AMIRA P754 code for metallurgical accounting. Initially the data are validated and pre-processed to remove gross errors and anomalies. Then, data reconciliation is performed using two mechanisms that distribute uncertainties between measurements, losses, and accumulated masses. The system was tested at Samarco S.A. using the Nexum® Digital Platform, Balance and Health modules, following technical specifications proposed by the mining company and proved to be successful in consistently attesting the total production, losses and accumulated mass throughout the entire chain.

Abstract:

Physicochemical variations in iron ore reverse flotation collectors are usually observed in industrial practice. In addition to the molecular and structural characteristics of amines, some physical parameters also influence the flotation process, such as density. For this application, this parameter ranges from 0.87 to 0.91. However, values close to 1.0g/cm³ can also be observed. Industrial testing at the tailings flotation plant in Mineração Usiminas was carried out with the Tomamine M-4713 collector manufactured by Evonik. Difference in collector density was observed in the performance of the test and correction of this parameter was made in the PLC of the processing plant. This factor, along with other characteristics intrinsically related to Tomamine M-4713, proved very favorable during the test. The results showed a reduction of 12% in amine consumption and a decrease of up to 0.63 percentage points in %SiO2 in the concentrate, compared to one of the periods tested. In addition to the production indicators, a reduction of 12% could also be observed in the consumption of new water for the preparation of the reagent plant, highlighting the value from the sustainable point of view of the tested product.

Abstract:

The road maintenance process impacts the efficiency and life of mining equipment, fuel consumption, and tire cutting. The project used RAC technology to monitor road quality, and Cascadia Scientific's heat map and machine learning tools to measure gains. The work carried out resulted in improvements in transport efficiency of 8.69% in liters per ton transported, and a 36% reduction in the cost of tires per ton transported, both compared to 2021 and 2022. The reduction in consumption represents savings of more than 14 thousand tons of CO2 emissions at Mineração Usiminas.

Abstract:

The use of Artificial Intelligence (AI) in industrial communication networks has been shown to be a growing trend. AI can be applied in various areas, such as data analysis, process control, predictive maintenance, and production optimization. Integrating AI into industrial communication networks allows for greater operational efficiency, cost reduction, and improvement in product and service quality. However, aspects such as information security and user data privacy must be considered. Through literature research, this article seeks to discuss the benefits and challenges of using AI in the context of industrial communication networks, as well as examples of its application for optimizing systems and processes.

Abstract:

The technology of using co-injection of natural gas and pulverized coal in the tuyeres to produce pig iron was applied in Blast Furnace 3 at ArcelorMittal Tubarão with the aim of reducing fuel consumption and reducing GHG. The present paper demonstrates the operational results in the period from September 2022 to January 2023 where up 33 kg/t of natural gas was injected in parallel with the reduction of pulverized coal and of the coke rate compared to the previous period only with coal injection. This action supports ArcelorMittal´s initiative to achieve its GHG net zero commitments by 2050 through products and processes with low CO₂ emissions.

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Convergent-divergent nozzles are widely used in Basic Oxygen Furnaces (BOF) to accelerate oxygen to supersonic speeds, allowing the process of decarburization of the hot metal. Different flow conditions, including overexpanded, underexpanded, and near ideal flows, exhibit distinct flow characteristics. The complex structure of the flow inside supersonic nozzles in the startup process includes shock waves, recirculation zones and expansion waves, factors that will affect the efficiency of the hot metal mixing process, due to the change of the potential core size. In this study, ANSYS Fluent® 2022 software was used for a 2D axisymmetric simulation of a trapezoidal converging-diverging nozzle similar to that used by ArcelorMittal Tubarão. The SST k-ω turbulence model was employed, and the analysis was performed in the transient regime. Schlieren pictures were used to analyze the phenomena that occurred in the startup of the supersonic jets. The results indicate that high nozzle pressure ratios (NPR) lead to high density gradients at the beginning of the flow in the nozzle, with the presence of incident shocks, contact discontinuity, and vortices. For low NPR values, early separation of the jet boundary layer is observed, causing a backflow that allows ambient air to enter the nozzle, reducing its lifespan. The size of the potential core also varies with NPR, and nozzles with higher pressure ratios present larger potential cores, which contributes to generating the turbulence required to induce steel refining reactions.

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One way to stimulate oil wells is to inject hydrochloric acid (HCl), but this fluid is very aggressive for most of metals used in oil & gas industry. This work evaluates the super duplex steel UNS S32750 degradation under similar acidizing wells conditions. It was found that stress levels influence degradation rate as follows: corrosion rate is higher on tensile surface, followed by the compression surface and finally neutral line. The corrosion rate ranged from 10.12 to 32.32 mm/year. The complex degradation rate and complex geometry of corrosion propagation, low MASS loss could be misinterpreted and lead to an accident.

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Hydraulic oil leakage is a common problem in industries. Excessive leakage is an environmental and safety risk, increases waste generation and oil consumption. The work proposed here refers to the reduction of hydraulic oil consumption, through good maintenance practices for detecting and eliminating leaks using analysis and troubleshooting methodology, technical training of maintenance teams and monitoring through reliable and consistent indicators

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Workplace safety in the mining industry is an extremely important discipline, given the potential for accidents to occur. A significant portion of the accidents that occur in this sector are directly related to maintenance activities, whether they are preventive or corrective. During these activities, equipment must be stopped before the start of the activity. However, some actions must be taken to ensure that the equipment does not return to operation before the activity is completed, involving the set of lockouts and tagout procedures and devices (LOTO). This work illustrates a solution for digitizing the LOTO process, as well as some control barriers, such as the need for field confirmation of the source to be blocked, preventing intervention in equipment that differs from the original. A conservative approach was adopted, with activities added gradually and training provided to employees working in the testing area. After implementation, a significant gain in safety and productivity was observed

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This work reflects on the implementation and predictive maintenance techniques in a medium-sized metalworking company. The goal is to contribute to the discussion of this topic in growing companies, due to the availability of more automated equipment, sensors with lower acquisition costs and the horizon for an industry 4.0. The study was developed from a review of technical literature in articles, books and the collection of information from reports and monitoring of activities at the company’s facilities during 2021 and 2022. The techniques studied were vibration, thermography, ultrasound and oil analysis. The research results confirm the benefits of failure prediction through systematic monitoring of machine condition and achieving the goal of 95% availability. However, it is suggested that the company analyze the possibility of real-time monitoring to reduce unplanned corrective actions.

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This study aims to analyze the state of aggregation and dispersion of charcoal, evaluating the influence of pH and a pre-defined reagent. In this context, the samples were initially characterized chemically and mineralogically, aiming to identify its main constituents and justify the phenomena observed. To achieve these objectives, sedimentation tests were carried out in the Galery tube, under different pH conditions and reagent dosages, analyzing the sample’s dispersion degree for the proposed variables. The results indicated that the charcoal presented a stable behavior only in the alkaline pH range and that the increase in pH and in the dosage of the reagent employed resulted in an increase, although not as expressive, in the sample’s dispersion degree. The sedimentation tube used proved to be efficient for the study of aggregation and dispersion of charcoal, enabling the understanding of the behaviors and phenomena associated with this material.

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The demand for car weight reduction obtained by reducing the steels thickness has led to the intensive use of high strength steels. In order to obtain parts with complex geometries using these steels, the process in which stamping occurs at high temperatures, called hot stamping (HS), was developed. Zn-Fe (GA) coated boron steels developed by Usiminas have been showing good results in tests conducted by the automotive industry. In this study, the corrosion resistance of three GA coating layer thicknesses (6 µm, 8 µm and 11 µm) was evaluated after HS, phosphating and painting processes. Regardless of the type of corrosion test performed, the results indicate that a higher initial coating thickness leads to lower rates of corrosion and/or peeling. Although the values obtained are lower than the typical requirements set by the automotive industry for e-coat-painted steels, the findings suggest that the three conditions evaluated could still meet the demands of this segment.

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Among the most varied types of materials, the study of basic alloys does not lose its significance; they form a group of fundamental value to industry, not only due to inherent process characteristics but also due the fact they are daily used in more varied industries. However, these materials also present some major challenges even though they are widely studied, once due to their wide applicability, they are subjected to various processing and applied in various systems. In this work were investigated the wear caused by the contact of nodular cast iron and SAE 1045 and the influence of different speeds using the same load and time. The mechanism of wear and the coefficient of friction were evaluated during the process.

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Lean duplex stainless steels (LDSS) are a new subgroup of duplex stainless steels (DSS) and were developed to be cost-effective alternatives to well-established steels such as DSS 2205. During severe deformation operations, the metastable austenite is partially transformed into martensite. After annealing, this transformation is reversed. This work aims to evaluate the effect of the formation of induced martensite and subsequent annealing at lowtemperatures on the mechanical and electrochemical behavior of LDSS 2304. For this, the hot-rolled and annealed LDSS was cold-rolled with a 74% reduction in thickness. Subsequently, isothermal annealing was carried out between 400°C and 600°C for 0.5 h. Microstructural, electrochemical and Vickers hardness analyses was carried out. The results indicated that cold rolling led to the formation of martensite induced by deformation and its reversion starts at temperatures between 500°C and 550°C. Hardening of the annealed specimens at 400°C and 500°C was noted when compared to the cold-rolled sample. Corrosion resistance was not impaired by martensite formation, but its reversion at temperatures higher than 500°C led to a large decrease in the pitting potential and an increase in the degree of sensitization.

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Additive Manufacturing (AM) is a set of techniques to produce components based in the continuous addition of raw materials, following instructions from a computer software. AM has 2 advantages compared to conventional techniques: its capability to produce components with complex geometries, feature extremely desirable in aerospace and biomedical industries, for example the fabrication of orthopedic prosthetics; and its saving of raw materials. Among the techniques, laser power bed fusion (L-PBF) is highlighted for its great number of parameters which influence the component’s properties, such as the laser power and the scanning speed. Studying those effects is a very important for the prosthetics need to satisfy certain conditions such human compatibility, and a Young’s modulus similar to the human bones in order to reduce injuries in the implant’s region. Results showed scanning speed proved to be is a parameter more determining than laser power for its greater influence over the pool depths and porosity morphology

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The present work brings an approach related to the reduction of the rolling load to perform the strain hardening of rolled strips through the change of shape of the working rolls by the implementation of a crown through the process of cylinder grind. To carry out the study, strips of 2.25mm thick and 1200mm wide SAE 1010 steel were skin rolling while the intended strain hardening was 0.8%. Skin pass occurred in a four-high strip mill that has bending and tilting controls. The rolling whose work was carried out is an integrated rolling and the steel strips used for this study were manufactured by the unit itself. The cold rolling of this unit until then worked with flat rolls (without crown), thus, the data obtained in the test rolling were compared with already known data and there was a significant change in terms of force required to generate the same degree of strain hardening of the material

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Expanded plates are meshes made from the opening of flat steel, providing a lower cost per area of ​​the final product, since the material often exceeds its original dimension. These materials are used as industrial partitions, machinery protection, various grids, floor plates, filtering elements, among others. The use of expanded stainless steel sheets for non-structural projects has become more and more comprehensive and for these applications smaller thicknesses are demanded, with corrosion resistance and aesthetic quality being the great advantage of stainless steel. For structural applications, such as industrial walkways, the material must also have outstanding mechanical properties. The behavior of corrosion resistance and mechanical properties of expanded plates was mapped and compared to carbon steel. Expanded stainless steel sheets were processed with thicknesses around 25% lower compared to carbon steel, given the greater mechanical resistance and aiming at cost reduction. Even with the difference in thickness, the stainless steel sheets presented limits of mechanical resistance and bending superior to those of the carbon steel sheet. The supremacy of corrosion resistance of stainless steel remained for expanded sheets.

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Cross wedge rolling is a complex and widely applied process to produce stepped shafts and preforms for the forging industry. The design of process tools represents a considerable challenge, and their geometric parameters control the tendency to generate defects. In this work, numerical simulation was applied to expose the specificities of the cross-wedge rolling tool designed. Finite element analysis was employed to define the optimum parameters for generating an axisymmetric preform for the forging process. In addition, the effects of the tool geometry parameters on product qualities was extensively discussed.

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The SAE 1080 steel, contains 0.79% to 0.82% of carbon, has greater mechanical resistance and lower ductility compared to low and medium carbon steels. It is a flat steel classified as high carbon and has a predominantly pearlitic microstructure. Some possible applications of this steel are: marble and granite saws, band saws, circular saws, handsaws, among others. The cost of customer complaints for this type of product tends to be relevant. In December 2017, SAE 1080 steel production began, intended for application in granite saws. The saws used in the looms are taken directly from the sheets of hot-rolled coils without the use of any subsequent heat treatment, being mounted on looms that vary between 80 and 140 blades. The variation in the microstructure is a critical issue that alters the hardness of the blades, which can cause breakage (in case of high hardness) or severe wear (in case of low hardness). Using the six-sigma methodology, variables that can influence the variation of the microstructure and, as a consequence, the variation of hardness of hot-rolled SAE 1080 steel were analyzed. After the analysis and implementation of actions, it optimized the length of the slabs in the melt shop and the coiling temperature in the hot rolling mill to optimal ranges, meeting the customer's SAE 1080 hardness requirements in this application

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Brazil has continental dimensions, making it a potential world producer of lithium, specifically, because it has two reserves of this element in the country, one in the southeast region and another in the northeast region. In this way, it is necessary to carry out studies to know their economic viability, enabling greater efficiency in the mineral sector of strategic minerals, mainly because lithium has essential properties for the development of the industry in the 21st century. Therefore, this work aims to produce a review of the literature on the processes of extracting lithium from the spodumene mineral. Therefore, the main processes used to obtain lithium, such as leaching, were researched in academic literature. In this process of mineral concentration there are two main ways to obtain the mineral: aqueous leaching and acid leaching. In this way, both were studied and presented, showing the advantages and disadvantages of their use and, especially, pointing out which would be the most appropriate method to be used in the extraction of lithium found in rocks in the Potiguar territory, especially in the Seridó region of the State.

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Mine Closure seeks to presume the last scenario of the mine, that is, the final years of the operation. Closure planning is carried out based on the final configuration planned for the assets in accordance with the mine's master plan. The closure of a mine, due to the impossibility of continuing mining activities, involves several environmental and socioeconomic aspects that require planning, management and provision of resources. It is important that, from the beginning of the project implementation activities, technical projections and budget forecasts are made for the closure of the structures that make up the mine project. The objective is to establish procedures and identify the activities necessary for the area to have desirable conditions for the implementation of the predetermined post-closure use. This closure planning involves the search for solutions to minimize negative impacts in the long term and includes the formulation of transition strategies for socioeconomic issues with a high focus on sustainability. The scenario here considers the planning of the closure of the tailings disposal program in Timbopeba, in the case of an enterprise belonging to the company Vale S.A, located between the municipalities of Ouro Preto and Mariana in the state of Minas Gerais.

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Dewatering processes are largely applied in mineral beneficiation. Filtering is among these technologies and allows for obtaining low residual moisture levels in solids; because of that, this method is commonly used for removing water from beneficiation concentrates and tailings. Currently, tailings disposal is a growing challenge for the mineral industry. Previously established solutions rely on tailings dams and these structures have been generating major social and environmental impacts, mainly in the iron ore field. In this context, dry stacking disposal becomes an interesting alternative. In order to meet this demand, press filtering has been regarded as the preferential technology. Therefore, understanding press filter selection methodologies is fundamental for those who intend to help developing more efficient solutions for iron ore tailings disposal. This paper presents important aspects related to press filter sizing, including testing equipment description, process parameters discussion, sizing procedures and a case study.

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In this article studies of several types of sceneries are presented. Firstly, we will consider the used variables and the methodology maid in this analysis. The simulation is one of the generalizations of the Operational Research (P.O), that comes growing with the current modernization. The analysis of sceneries through simulation allows a verification of the data and the summarization of a variety of reports for support to the management of a mine. The work contemplates a case study accomplished in the mine of Tamanduá, of MBR - Minerações Brasileiras Reunidas, in the Ferrous Quadrilateral. The objective of this study is to show and to compare through you analyze of sceneries using the simulator SIMIN, the shipment operations and transport of sterile of this mine.

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Due to the long period of exploitation of iron ore deposits in the Brazilian region of the Iron Quadrangle, there have consequently been changes in the mineralogical characteristics of the mineral deposits in this region over the years. When iron ore production began in Brazil in large volumes, around the first decades of the 20th century, the mineral deposits contained a high iron content, requiring only fragmentation and classification steps. However, over the years, these deposits became impoverished, thus requiring the adoption of new processes to ensure quality production. Currently, this region is preparing for yet another change that will occur in the characteristics of its mineral deposits, as the reserves with the presence of friable rocks are increasingly close to being depleted, starting the exploration of deposits containing compact rocks, thus requiring the readjustment of its processes so that the continuity of iron ore production is feasible. Due to these mineralogical changes, companies increasingly seek to study new process routes, where it is possible to reduce operating costs in these readjustments. Therefore, the route with the adoption of AG/SAG milling for the comminution stages of this new type of rocks present in the next nearby reserves, demonstrates great economic potential.

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The construction industry consumes large amounts of energy and raw materials and is a considerable source of air pollutants, mainly greenhouse gas emissions. An alternative under development to mitigate these problems is the use of pozzolanic materials developed from waste. This article aims to carry out a bibliographic review regarding the incorporation of pozzolanic materials derived from agro-industrial residues in mortar, highlighting processing and resulting effects. Studies indicate the feasibility of using pozzolans from the agricultural industry, using biomass such as rice husk ash, palm oil ash, bamboo leaf ash, sugarcane bagasse ash and ash of corn waste, including cob, stalk and straw. These ashes, containing a large amount of silica in amorphous form, have the potential to be used as pozzolanic materials to replace cement. The analysis of the cementitious properties of these ashes can contribute to the production of eco-efficient cements with lower costs, in addition to their safe disposal. It can be stated that the use of these residues as a pozzolanic material with adequate processing and percentage of cement replacement leads to a gain in mechanical strength and encourages the reduction of construction costs

Abstract:

The iron ore produced in Brazil is basically extracted from open pit deposits, whose main lithologies are hematites, itabirites, in addition to several variations. Low-grade itabirite ores are normally submitted to two processes responsible for the generation of tailings from the beneficiation process. Flotation is the concentration process whose sandy tailings are basically composed of silica, while desliming is responsible for the removal of a large part of the secondary deleterious minerals such as Alumina, Gibbsite, Kaolinite, etc., making up the ultrafine tailings. The mixture of sandy and ultrafine waste makes up the total process waste. For some current operations, the disposal of the total tailings is carried out in tailings dams, however, for new plants, in addition to some suitable plants and in favor of the integrity of people and the environment, the way of stacking was changed from hydraulic launching in dams for vertical stacking in piles known as PDR (Tail Disposal Pile) or even PDER (Sterile and Waste Disposal Pile). In order to dispose of it in piles, the material is drained in filtering installations that use conventional disc filters and in some cases also the filter press. The work in question aims to fill some gaps related to the filtering of tailings, presenting some concepts and learnings with this type of operation during the last years. Process aspects related to sizing, operation, filters and their subsystems will be highlighted, such as vessel separators, cleaning circuits and process tests, in addition to pointing out some important points related to good maintenance and operation practices to ensure satisfactory operation of the tailings filtration using conventional disc filter.

Abstract:

The use of natural lignocellulosic fibers as reinforcement in polymeric composites to produce low-cost engineering materials has generated much interest in recent years. One of the main challenges of eco materials lies in the fact that both polymers and natural fibers are prone to degradation when exposed to different environmental conditions. In the accelerated aging process, natural light is replaced by a xenon arc lamp, as ultraviolet light can cause partial degradation of macromolecules in the polymeric matrix, as well as aging and failure of the polymer. The dynamic-mechanical analysis, also known as thermodynamic-mechanics, was performed in the present work to obtain information on the viscoelastic behavior, such as storage modulus (E'), loss modulus (E") and the ratio between these modules, tan δ, and also the glass transition temperature (Tg) of the samples from the evaluation group. As a result, it was observed that there was an increase in the Tg of the aged composite compared to the control group, as well as a decrease in the peak of tan δ, indicating the greater elasticity of the material. The modulus of loss substantially reduced in relation to the control group, in the order of 43, 56 and 73% for exposure for 250 h, 500 h and 750 h, respectively.

Abstract:

Ferrites are ferromagnetic materials with several applications in the form of nanoparticles, such as in the manufacture of supercapacitors and in the treatment of cancer. This work aims to synthesize nickel ferrite nanoparticles by two different methods, direct combustion and sol-gel/combustion, and characterize these particles using X-ray diffraction and ferromagnetic resonance.

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The objective of this work was the incorporation of a so-called combustible waste (cocoa husk) in ceramic mass, evaluating the properties of fired ceramics. The raw materials were evaluated by FRX. Formulations were made with different percentages of the waste, which were burned at temperatures of 850 and 950ºC with a rate of 3ºC/min and kept at the plate temperature for 180min. Afterwards, the following properties were evaluated: water absorption, linear shrinkage, and flexural rupture strenght. The thermal behavior was evaluated by linear dilatometry. With the results obtained, it was observed that because it is a waste with a large amount of organic matter, the amount must be evaluated in order not to impair the properties of ceramics. With this, it is possible to conclude that the incorporation of this waste in ceramics is a very advantageous alternative for the ceramics industry, where there is energy saving in the burning process

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Waste from industrial processes has grown in number and volume. Finding sustainable alternatives for the disposal of this waste is an increasingly necessary and urgent task. One of these waste is obtained in the lactic acid purification process, through the reactive distillation process, where calcium lactate precipitates. In this process, a large amount of gypsum is generated, which is considered an environmental contaminant. Thus, the present work aimed to characterize and incorporate in red ceramic a residue from the lactic acid production process, known as industrial gypsum. The raw materials were characterized in terms of chemical composition (FRX). , 2.5, 5% by weight of waste to a traditional ceramic mass from the Campos dos Goytacazes region. Ceramic pieces measuring approximately 120x30x20 mm were produced by extrusion, dried at natural temperature and in an oven, and fired in a laboratory oven at temperatures of 700, 800, 900 and 1000ºC. Physical and mechanical properties were evaluated. The results show that the incorporation of the waste in red ceramic is feasible and that there is no loss of properties. It was also possible to verify the appearance of efflorescence for all percentages of waste incorporation

Abstract:

As the process generates some waste, the recycling market has been growing, as environmentally correct forms of disposal are needed. Given the above, it is essential to find ways to reuse waste, and an alternative would be incorporation into the ceramics industry. Thus, the objective of this work was the incorporation of a so-called combustible waste (jabuticaba peel) and a flux waste (packaging glass) in a ceramic mass, evaluating the properties of fired ceramics. The raw materials were evaluated by FRX. The raw materials were dried and sieved so that formulations could be made with different percentages of wastes, which were burned at temperatures of 750 and 850ºC with a rate of 3ºC/min and kept at the plate temperature for 180min. Afterwards, the following properties were evaluated: water absorption, linear shrinkage, and three-point bending stress. The thermal behavior of the formulations was evaluated by linear dilatometry. With the results obtained, it was observed that because it is a waste with a large amount of organic matter, the jabuticaba peel alone would harm the properties of ceramics, and should only be used in small quantities. When blands were made with the two wastes, even burning at lower temperatures, there was a significant improvement. With this, it is possible to conclude that the incorporation of the mixture of the two wastes in ceramics is a very advantageous alternative, both from the environmental point of view, for the disposal of these wastes, and for the ceramic industry, where in addition to improving the quality of the pieces, it has savings energy in the burning process

Abstract:

The mass loss causes low density of the sintered SiC via liquid phase, compromising its thermo-mechanical properties. The objective of this work was to develop a new route for sintering silicon carbide (SiC). Having as specific objectives: (i) to study the behavior of SiC with Al2O3 and Y2O3; (ii) examine the structures, phase evolution and mass loss of pure SiC, SiC − Al2O3, SiC − Y2O3 and SiC − Al2O3 − Y2O3 compositions, at increasing temperatures (500 to 1400°C ); (iii) investigate the encapsulation of the samples using a carbon source (SiC or graphite), in an oxidizing and inert atmosphere; (iv) Compare the new processing route with the conventional route (high temperatures and inert atmosphere). Thermal analysis (TG) up to 1600ºC, in argon atmosphere and SEM AND XRD of the powders as received. SiC presents a mass gain that is not very expressive at approximately 900ºC. SiC with the addition of Al2O3 and Y2O3 also shows little expressive gain.

Abstract:

Different composite materials with polymeric matrices have already presented the minimum performance as an individual protection required with cheaper and lower density, such as those reinforced with natural lignocellulosic fiber (NLF). However, with the huge variety of vegetal species around the world, unknown fibers might present promising mechanical behavior. Thus, the present work aims to investigate the ballistic performance of a composite with epoxy matrix reinforced with a novel Cyperus malaccensis (CM) fibers. The tests explored the limit and residual velocity of composites in three different conditions, 10, 20, and 30 vol.%. Afterwards, fractured surfaces were analyzed in a scanning electron microscope (SEM) for a deeper investigation of the failure mechanism. From the tests, it could be observed that the composite plates reinforced with 20 vol.% of CM fibers presented the highest value of energy absorption (222.11 J) and limit velocity (231.34 m/s), although the ones reinforced with 30 vol.% showed a more complete physical integrity. For this group, the SEM micrographs presented the mechanisms of failure related to delamination and fiber rupture. The 10 and 20 vol.% reinforced plates presented a slight difference in residual velocity (810.27 and 808.37 m/s, respectively).

Abstract:

The sedge fiber extracted from the Cyperus malaccensis (CM) plant has recently been found as a promising reinforcement of polymer composites. Incorporation of 30 vol.% CM sedge fibers improved the impact resistance, tensile and elastic modulus of epoxy composites with only slight differences in their thermogravimetric parameters. However, dynamic mechanical viscoelastic behavior is still needed to complete these composites characterization for possible engineering applications. Therefore, this research aims to investigate to dynamic mechanical (DMA) and thermal mechanical (TMA) analysis for GO-incorporated epoxy matrix nanocomposites incorporated with 30 vol.% of CM sedge fibers. In comparison to basic epoxy (control sample) the damping factor (Tan δ), as the ratio between DMA loss and storage moduli, is significantly increased from 0.45 to 0.75 for 30 vol.% CM fiber composite. TMA findings disclosed only slight variations in the glass transition temperature (119 to 124 °C) as well as in the thermal expansion coefficient (168 x 10-6 to 220 x 10-6/°C). These DMA and TMA results reveals the promising CM sedge fiber reinforcing effect on GO-incorporated epoxy nanocomposites and its mechanical / thermal viscoelastic contribution.

Abstract:

Increasing awareness around the world of the urgent need to reduce the use of non-degradable synthetic materials, and the problem of disposing of personal protective vest and helmet have driven research into new more environmentally sustainable materials for ballistic applications. In this context, natural lignocellulosic fibers can be promising options because they are non-polluting and have specific mechanical properties comparable to those of commonly used synthetic fibers, in addition to being significantly cheaper. Thus, in order to evaluate the hybridization of curaua fibers (Ananas Erectifolius) with aramid fibers in epoxy composites for ballistic helmets, thermogravimetric analysis (TGA), derived thermogravimetric analysis (DTG) and differential thermal analysis (DTA) were performed. From the obtained results, it can be inferred that the hybridization was positive in relation to composite thermal behavior, considering that there was no significant variation in the temperature at the beginning of the decomposition process.

Abstract:

Increasing awareness around the world of the urgent need to reduce the use of non-degradable synthetic materials, and the problem of disposing of personal protective vest and helmet have driven research into new more environmentally sustainable materials for ballistic applications. In this context, natural lignocellulosic fibers can be promising options because they are non-polluting and have specific mechanical properties comparable to those of commonly used synthetic fibers, in addition to being significantly cheaper. Thus, in order to evaluate the hybridization of curaua fibers (Ananas Erectifolius) with aramid fibers in epoxy composites for ballistic helmets, thermo-mechanic analysis (TMA) was performed. From the obtained results, it can be inferred that the hybridization was positive in relation to composite thermal behavior, considering that the glass temperature of the composites about 160°C was sufficiently high.

Abstract:

Increasing awareness around the world of the urgent need to reduce the use of non-degradable synthetic materials, and the problem of disposing of personal protective vest and helmet have driven research into new more environmentally sustainable materials for ballistic applications. In this context, natural lignocellulosic fibers can be promising options because they are non-polluting and have specific mechanical properties comparable to those of commonly used synthetic fibers, in addition to being significantly cheaper. Thus, in order to evaluate the hybridization of curaua fibers (Ananas Erectifolius) with aramid fibers in epoxy composites for ballistic helmets, ballistic protection level test was performed. From the obtained results, it can be inferred that the hybridization was positive in relation to ballistic protection level, considering that hybrid composite obtained the maximum level according to the NIJ 0106.01 standard for ballistic helmets.

Abstract:

Increasing awareness around the world of the urgent need to reduce the use of non-degradable synthetic materials, and the problem of disposing of personal protective vest and helmet have driven research into new more environmentally sustainable materials for ballistic applications. In this context, natural lignocellulosic fibers can be promising options because they are non-polluting and have specific mechanical properties comparable to those of commonly used synthetic fibers, in addition to being significantly cheaper. Thus, in order to evaluate the hybridization of curaua fibers (Ananas Erectifolius) with aramid fibers in epoxy composites for ballistic helmets, residual velocity test was performed. From the obtained results, it can be inferred that the hybridization was positive in relation to ballistic limit, considering that the reduction in the amount of aramid was significantly greater than the reduction in this property.

Abstract:

The titica vine fibers (Heteropsis flexuosa) demonstrated great potential for use as reinforcement filler in polymer matrix composites. In the present study, were produced composites with epoxy titica vine the volume fractions of 0% to 40%, for the purpose of ascertaining the average Izod impact energies. For 40% v/v fibers composites, there was a more efficient performance of the reinforcement, with the predominance of mechanisms such as interfacial detachment with the epoxy matrix and fiber rupture, observed from the SEM. The Tukey test confirmed that 40% v/v fibers composites achieved better performance, reaching an energy absorption of 58.65 J/m. However, it was also found that the fibers acted as a weakening agent in composites of 10% and 20% when compared to the control group (pure epoxy

Abstract:

The titica vine fibers (Heteropsis flexuosa), when incorporated into an epoxy matrix, showed good potential as a reinforcing filler in these new materials. In this research, titica vine fiber composites were manufactured in volumetric fractions of 0% - 40%, with the objective of evaluating the average Charpy impact energies. For composites with 40% v/v fibers, the reinforcement was more efficient, with a predominance of mechanisms such as pull-out and fiber breakage, which could be seen from the SEM. The Tukey test confirmed that the composites with 40% presented better performance compared to the control group (pure epoxy), as well as the fractions of 20 and 30% v/v of fibers, reaching an energy absorption of 75.05 J/m. However, it was also verified that the fibers acted as an weakening agent in the 20% composites.

Abstract:

Artificial aging is defined as aging processes that are accelerated by simulating the external climate in the laboratory. For example, heat and oxygen are key factors in the aging process of polymers. The mechanisms of aging by oxidation can be investigated by monitoring the mechanical properties of a material exposed to aging in an oven/stove for a long time, which is called accelerated aging process by thermal oxidation. The dynamic-mechanical analysis, also known as thermodynamic-mechanics, was performed in the present work to obtain information on the viscoelastic behavior, such as storage modulus (E'), loss modulus (E") and the ratio between these modules, tangent δ, and also the glass transition temperature (Tg) of the samples of composites reinforced with 40% by volume of fiber fabric, with additions of 0.1, 0.5 and 0.9% by mass of graphene nanoplates, and thermally aged. As a result, it is noteworthy that there was an increase in the initial E' with the incorporation of graphene nanoplates. Regarding the composite control group, there was a reduction of up to 40% of the E', as well as a considerable reduction in the E peak" of GC C, of 56%, 48% and 49% for GC 0.1%, GC 0.5% and GC 0.9%, respectively. The appearance of a second peak in the tan δ graph for the 240 h aged condition for all nanoplate addition conditions.

Abstract:

Silicate-based bioceramics have been developed with the intention of being an alternative to calcium phosphates in the integration with biological tissues, as they have better mechanical resistance and thermodynamic stability[1,3]. In this context, this work aims to analyze the crystalline structure, bioactivity and morphology of samples of magnesium silicate with addition of zinc oxide. The characterization of the composites was performed using density measurements, linear shrinkage, X-ray diffraction, scanning electron microscopy with field emission source (FEG-SEM) and X-ray fluorescence spectrometry. in artificial saliva and analyzed using SEM in order to study its bioactivity. Finally, it was found that the addition of zinc oxide, in the right measure, enhances the bioactivity of the silicate, considering that increases in the deposition of calcium and phosphorus were observed in the samples with zinc.

Abstract:

Abstract:

A torpedo ladle car is refractory-lined wagon that transports liquid pig iron from the blast furnace to the steel mill and should undergo periodical maintenance. In this article, we developed an exponential smoothing model capable of estimating when each vehicle should be collected for refractory lining repair. The previously used method relied on a set transport rate based on the fleet's history of maintenance and human experience. The new method employs a unique dynamic rate for each vehicle, which is updated daily using the exponential smoothing technique, with parameters computed depending on the car's traveling history. The new method allows also for the calculation of confidence intervals for the forecasts. The results indicate that the strategy utilized here is capable of significantly improving forecasts of maintenance and repairs.

Abstract:

Knowing the importance of steel for the automotive industry in the manufacture of exhaust pipes and welding as the main means of joining metallic materials, a study was carried out in order to evaluate the factors that influence the occurrence and degree of sensitization in stainless steel AISI 409 and AISI 439, the Double Loop Dynamic Potential Test (DL-EPR) method is used, following the ASTM G108 standard to generate the polarization curves, it was observed that in the evaluation of the degree of sensitization of the parts the best performance of the steel 439 in relation to 409 and tubular wire in relation to solid wire, it was also verified that the pieces after going through a cycle of thermal and mechanical fatigue do not tend to increase their tendency to sensitization

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The effects of heat treatment leading to α phase formation during ageing were analyzed on the light of microstructural evolution and the mechanical propertie of a duplex stainless steel 2205 (DSS) and a lean duplex stainless steel (LDSS) 2304. For this, hot rolled samples of 4 mm thickness were heat-heated at 500ºC by 0.5, 2 and 24 h. The X-ray diffraction (XRD) was used to quantify the phases volume fraction. The texture was analyzed by means of the orientation distribution function (ODF). After the hardness tests, all samples had an increase in their values. For the temperature of 500ºC and times employed, beside an increase in the hardness, slight changes were observed in the EBSD maps obtained by backscatter electron diffraction images as well as in the X-ray diffraction patterns.

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This article presents a procedure for assessing the operational feasibility of two scenarios proposed by ArcelorMittal with the aim of increasing the handling capacity of its port terminal. The procedure was developed based on time and motion studies, simulations in Microsoft Excel software and in the Python programming language. It is capable of determining whether the scenarios are feasible within the terminal's operating time, as well as the increase they offer compared to the current scenario. The methodology adopted can be easily replicated for other logistics operations with different levels of conservatism in it analyses. The results contribute to a better decision-making process regarding the selection of different scenarios.

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Ferrite-Bainite (FB) steels are a somewhat neglected part of the first generation of Advanced High Strength Steels (AHSS). The combination of ferrite and bainite in the microstructure provides improved stretch flangeability of sheared edges when compared to steels such as Dual-Phase and High Strength Low Alloy (HSLA) steels, other viable candidates for the same applications. Therefore, FB steels are more suitable for parts with complex edges requirements. Furthermore, the production of this steels only uses hot rolling, with no need of cold work or further heat treatments, which makes them cheaper than other options. During an effort to produce a new industrial FB590, the effects of niobium and molybdenum addition in the microstructure distribution were investigated. Electron Backscatter Diffraction (EBSD) was used for the microstructural characterization. The influence of the microstructure on the mechanical properties of the steels was investigated by tensile testing

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3rd generation advanced high-strength steel (AHSS) grades are complex materials with special chemical compositions and multiphase microstructures. The annealing and galvanizing process of these grades is different and places new demands on the plant technology. One of them is the prevention of surface faults. Bare spots can occur due to a higher content of alloying elements like silicon or manganese. Prevention is possible with the PrOBOX®-technology for pre-oxidation. This technology is a proven solution for hot-dip galvanizing of high-alloyed steel grades without wettability problems, which normally occur during the conventional galvanizing process. Another important topic is a precisely controlled and very flexible heating and cooling processes. Crucial for the production of modern grades is an appropriate furnace technology. The highly-efficient radiant-tube furnaces are equipped with powerful heating and cooling systems and facilities for quench and tempering. The newly developed I-Furnace optimizes the heat treatment and production process. This paper presents concepts for modern galvanizing lines for the production of 3rd generation advanced high-strength steel grades

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The performance of a Steel Shop depends on the stability of its equipment, and the thermal balance of the BOF is essential to guarantee the thermal stability of liquid steel, reducing downtime for reheating, adjusting the tapping temperature, as well as avoiding thermal losses to the metallic shell. One way to improve the thermal balance would be the use of insulators in combination with the working refractory material. This work is unprecedented in the use of insulators in BOF, with implementation at the Usiminas Steel Shop in BOF#4. The results observed during the campaign increased BOF productivity, reduced downtime for reheating, improved refractory lining and increased shell life.

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The casting process takes place through the passage of steel from the steel pans to the distributor and this is responsible for conducting, controlling, cleaning and distributing this steel to each shaft, in these there are copper molds that are responsible for cooling the steel in the desired shape; The steel at this stage has temperatures in the range of 1550⁰c and the more process controls we have, the more security we will achieve in the system. In the preparation of the distributors, refractories of the working coating are applied to the walls and bottom, in this process an immense amount of water is used, which can reach 33% of the mass of refractory applied, the water in contact with the steel at high temperature vaporizes generating a great volumetric expansion which projects everything that is in the way generating serious accidents; In order to avoid accidents, a case of water dripping through the casing of a distributor was studied, detailing all the entrances and exits of water in the refraction process, in this way we will quantify the volume of water present in a distributor during its operation and methods to avoid accidents

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Since taking over operations at the Resende Plant, in 2018, the ArcelorMittal Group has promoted actions to reduce the consumption of electrodes in the Electric Arc Furnace (EAF). In the last quarter of 2020, a work group was created to analyze the possible causes of the high consumption of electrodes. This work group found a strong relationship between skull formation in some regions of the electric arc furnace (EAF) and electrode breakage. This paper aims to present the methodology carried out between Lumar Metals and ArcelorMittal Resende teams in the characterization of the problem, and planning and execution of actions to avoid the formation of skulls in the EAF and consequently to avoid electrode breakages. The result of the actions proposed by the work group was a considerable reduction in the consumption of electrodes and also greater process stability, due to the reduction in electrode breakage events.

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The demand for artificial stones has been growing a lot nowadays, as they have superior properties when compared to natural ornamental rocks, in addition to their aesthetic appeal, considering that they can present the most diverse colors and compose any environment. Brazil has been importing this type of material a lot, so research aimed at developing it is very important to economy of the country. The objective of this work is to produce an artificial stone from wollastonite powder agglomerated by epoxy resin, for this, a mixture was made and transferred to a metallic mold, under vibration and vacuum and, later compressed. The plates were subjected to density, water absorption and apparent porosity test, three-point bending tests and microstructural analysis. The developed stone showed high levels of water absorption and apparent porosity, confirmed by micrographs made by SEM, however the developed stone was considered to have very high mechanical strength

Abstract:

The steel industry has faced challenges with regard to the raw materials and fuels and hence economic and environmental restrictions. This paper is focused on searching alternatives based on biomass and gaseous fuels suitable for replacing the coke breeze fossil fuel. The iron ore sintering process is a key technology in the steel industry due to its possibility of recycling waste solids or powders internally produced during the raw materials handling or subsequent process of steel production. However, this process is also recognized as one of the most critical unit with regard to particulates and polychlorinated dioxins and furans (PCDD/F) emissions. The outlet gas treatment involves the cleaning with electrostatic precipitator and filter bags. New technologies, however, have been introduced in order to treat PCDD/F and SOx-NOx compounds, which introduce significant increase in the cost of the production. New process concepts and technologies have been proposed such as gas recycling, fuel gas injection and biomasses fuels besides recycling waste solids replacing natural raw materials. Nevertheless, testing these technologies are expensive. Therefore, comprehensive mathematical models based on transport phenomena are efficient tools to study and indicate new possibilities for designing operational conditions as well as resizing the machines for minimizing the hazardous emissions. In this study, the model principles and analysis cases are presented and discussed. A technological proposal for using waste solid biomass in the iron ore sinter process is analyzed using the specific hazardous emissions of PCDD/F, NOx, SOx and particulates as decision parameter. The results indicated that about 20% of the solid fossil fuels could be replaced by waste solid residue of biomass (processed as small pellets) generated during the charcoal production and handling and wood processing

Abstract:

Nickel has been widely used in the production of stainless steel and other metal alloys. Furthermore, the increase in the production of electric cars has led to the development of new technological routes for processing lateritic ores, which represent around 70% of the world's nickel deposits. Cobalt is a by-product of nickel production and due to its numerous applications in high technology products, and because its production is concentrated in a single country, it is considered a critical raw material for the European Union.The present study aimed to compare the performance of sulfuric acid and citric acid in the recovery of nickel and cobalt from a nickel limonite ore using atmospheric leaching. The results obtained indicated that within the limits established for the tests carried out, citric acid presented the best performance, with estimated recoveries of Ni and Co of 60% and 100%, respectively. While recoveries using sulfuric acid for Ni and Co were approximately 35% and 50%, respectively. .

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this work evaluated the performance of lab filtration tests (leaf tests) with different mixtures of iron ore tailings (flotation tailings - sandy, and desliming tailing - slime) with and without the use of a filter aid. Firstly, filtering unit rate results, moisture and percentage of solids in the filtrate were evaluated with sandy tailing (reference), 90/10 mixture (90% sandy and 10% slime) and 80/20 mixture (80% sandy and 20% slime), without the use and with the use of a dosage of 50g/t of a filter aid. Then, to deepen the results of the 90/10 and 80/20 mixtures, leaf tests were carried out with mixtures 80/20 (80% sandy and 20% slime) and 90/10 (90% sandy and 10% slime), in four dosage levels: without reagent, 80g/t, 100g/t and 150g/t. TUF results in the 80/20 mixture were less than 0.4t/h/m2, even with higher dosages of filter aid. For the 90/10 mixture, the addition of filter aid promoted increases in filtering unit rate, despite the increase in moisture in the mixture. The difference in worse filtration performance of the 80/20 mixture compared to the 90/10 mixture was remarkable.

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