ABM WEEK 6ª edição | Schedule

Abstract:

The blast furnace sludge is one of the most difficult waste to manage. This, among other factors, is due to the impact on the handling, transport and storage process resulting from a poor separation between phases: liquid-solid. Thus, it is interesting for companies in the industry to monitor the efficiency of sludge treatment systems with regard to quality and operational safety. Therefore, the work compared the productive efficiency between a centrifugal machine and a vacuum filter, explaining all the issues that justified the replacement of the separation technology to obtain better results. The study navigated areas of knowledge, established granulometric profiles, chemical and mineralogical characteristics of the mud; analyzed the moisture content of the pies, in different scenarios, associating it to the results of concentration of solids in the filtered water; monitored the behavior of thickeners and determined the financial gain with freight resulting from the cost of transporting solids with lower moisture content. Thus, it was possible to verify that the centrifugation process generated a productive performance superior to that of vacuum filtration in the period analyzed for technical and financial reasons.

Abstract:

The traditional reduction process of graphene oxide (GO) is sometimes delineated by obstacles and socio-environmental problems that are mainly associated with the use of harmful chemical compounds such as hydrazine and sodium borohydride. To minimize the impacts and adversities caused by these substances, this study presents an alternative model for the production of reduced graphene oxide (RGO), in which naringenin from the citrus industry was used as a reducing agent for OG. It is important to highlight that the use of antioxidant substances extracted from agro-industry residues to obtain graphene derivatives is configured as an environmentally friendly, economical, and innovative alternative. To measure the antioxidant action of naringenin and to observe the particularities of the material, characterization techniques were used: Scanning Electron Microscopy (SEM); X-ray Diffraction (XRD); Fourier transform infrared spectroscopy; Raman spectroscopy; Thermogravimetry and Differential Exploratory Calorimetry. Based on the results, naringenin was shown to be effective in terms of the graphene oxide reduction process, thus being a viable and sustainable candidate for the production of OGR.

Abstract:

This contribution shows the development carried out to meet the needs of the Customer for a cold strip mill (TCM) in processing products for different production flows with only one type of rolling oil rather than two types. The application only one oil was necessary due to the operational restrictions imposed by the use of two types of oil, one oil for the main system (2nd to 4th stand) and another for the 5th stand. By the correct definition of the needs provided by the Customer, an appropriate product was developed by the rolling oil supplier based on scientific studies, as well as the development conducted by the same team in the process-product adjustments. The development of the product, since its formulation and simulation tests were carried out in the Laboratory of the oil supplier in Japan and the application of the product developed on an industrial scale in Brazil, began in August 2018, with the completion of the adjustments of the parameters of the resulting emulsion in December 2020. The results obtained were satisfactory in terms of production process, environment, oil consumption, safety and product quality.

Abstract:

This paper is dedicated to the challenges and solutions for machining tasks in roll shops of wire rod, rebar and long products mills around the world. Modern technologies available in 2021, which are required for succeeding in the coming decade, are being presented. Special emphasis is given to the automation of the process.

Abstract:

INTOCAST was founded in 1979, operating primarily in the non-moulded, casting materials and synthetic slag market. Through mergers and acquisitions, it began to operate in the molded refractories market since 2017. In July 2020, it sold its first converter lining in South America with Ternium Brasil. It surpassed the previous record by 16%, without restrictions operating and low-mass hot repair under 0,20 kg/t. In addition to the life record of the lining, it is emphasized that this result was obtained without applying restrictions of the steel mix and temperature, which were common in previous campaigns. Another significant result was the efficient operation of the combined blow until the end of the campaign. A key factor for the result achieved is the supplier and customer partnership, because the appropriate choice of refractories used, combined with the best practices of the client and management of key variables of the process, such as slag analysis, particularly the CaO/SiO2 ratio, MgO and FeO contents, level of oxidation of the bath, temperature, and maintenance techniques, provided this expressive result.

Abstract:

TENOVA'S INTELLIGENT EAF TECHNOLOGY (I EAF®) IS A PROCESS CONTROL PROGRAM FOR THE OPTIMIZATION OF ELECTRIC ARC FURNACES (EAF) AND IS BASED ON THE REAL-TIME MEASUREMENT OF EAF OFF-GAS AS WELL AS THE APPLICATION, IN REAL-TIME, OF PROCESS MODULES AND CONTROL ALGORITHMS FOR THE DYNAMIC CONTROL OF THE MELTING PROCESS. THIS TECHNOLOGY IS PART OF TENOVA’S PROCESS CONTROL SOLUTION THAT IS DESIGNED TO MEET THE NEEDS AND REQUIREMENTS OF THE DIGITAL TRANSFORMATION ERA AND INDUSTRY 4.0 FOR MANUFACTURING. THIS PAPER WILL OUTLINE THE PERSPECTIVE OF TENOVA'S DIGITAL PLATFORM FOR EAF PROCESS CONTROL, INDICATING THE INTEGRATION OF THE I EAF® SOLUTION, BOTH HARDWARE AND SOFTWARE AND DIGITAL CONNECTIVITY OF EACH ELEMENT. RESULTS ACHIEVED FROM RECENT INSTALLATIONS USING THE DIGITAL PLATFORM ARE ALSO DISCUSSED.

Abstract:

In the context of advancing digitalization, certification is playing an increasingly important role. It is often a prerequisite for steel producers to be able to sell their slabs to automotive manufacturers. To obtain such certification, a continuous process for the production of high-quality slabs and their subsequent treatment must be established. Usually, the various processing steps take place at different locations within the mill. With the fully automatic inline slab inspection system, SMS group has developed a new concept for this treatment process and brought the different processing steps together in one line: the slabs pass through a consistent process, which essentially includes the scarfing, descaling, three-dimensional inspection, and grinding of specific areas of the slab surfaces. In the scarfing process, all four surfaces – the two broad and the two narrow faces – are treated. This can be achieved by turning the slab 180°. The top and bottom faces of the slab are then automatically inspected by two and three-dimensional systems. Any defects detected in the process are eliminated by grinding the two broad faces, which can also be performed thanks to a 180° turn. In a final step, the slabs are provided with an identification mark and transported to the slab yard. Using an interface with level 2 of the X-Pact® electrical and automation system, feedback can be given on each slab leaving the line after treatment. This allows for continuous documentation of the entire process.

Abstract:

The Ni-Ti system alloys have properties that are extremely interesting for the market, which combine the characteristics of shape memory effect (EMF) and superelasticity (SE). However, it is observed that these alloys have great behavioral sensitivity in relation to their composition, thermomechanical conditions and the presence of impurities, giving rise to the processing of alloys with different types based on NiTi intermetallic. In this context, the addition of niobium maintaining an atomic proportion of 47Ni-44Ti-9Nb causes an increase in its thermal thermal, without extinguishing, however, its EMF. In the present work we sought to produce an alloy of the Ni-Ti-Nb system via powder metallurgy, via conventional sintering (SC) and an end of observation microstructural evolution of the 47Ni-44Ti-9Nb alloy. As they were analyzed via optical microscopy, scanning electron microscopy and X-Ray diffraction, where the collected results indicated that the temperature was insufficient for the formation of a formation mainly of NiTi-B2, despite having evidence of its presence in the samples. In addition, there was little difference in porosity comparing the pressed at 6 ton with the pressed at 9 ton, despite an increase in density.

Abstract:

The blast furnace trough is an important equipment in the blast furnace manufacturing process. One of its functions is to promote separation between the hot metal and the slag. However, due to turbulence during tapping, metal droplets can be trapped in the slag layer leading to important losses. The economic impact of metal losses is important since large tonnages are involved. The flow pattern inside the blast furnace trough is understudied due to its complexity as it is highly dependent on the physical properties of the fluids, variables of the casting process and geometric characteristics of the blast furnace trough itself. Metal losses can be traced to the flow pattern. This aspect is discussed using computational modeling. The focus of this work is to evaluate the separation efficiency in blast furnace trough of different geometries. Improving slag-metal separation can provide significant economic gains in an operation that is often neglected in integrated steel mills.

Abstract:

During the sintering of iron ore pellets, the action of calcium oxide (CaO), obtained through the addition of limestone, is essential. Blocks of waste from marble mining have a chemical composition similar to that of limestone, and can replace it as a basicity corrector and flux during the sintering of the pellets. Pilot-scale tests were carried out for chemical and physical characterization, crushing and grinding tests on samples of marble residues and pellets produced using the residue as a basicity corrector and flux. Physical strength, microstructure and metallurgical behavior of the pellets were evaluated. The results show that the application of marble residue in the production of iron ore pellets maintained the same level of chemical, physical and metallurgical quality of the pellets when compared to those produced with limestone. Thus, the use in the production of pellets is a sustainable alternative for the destination of large volumes of marble waste generated in the production of ornamental stones. Keywords: Blocks; Waste; Marble; Pellets; Iron ore

Abstract:

INDUSTRY, ECONOMIC AND PUBLIC-HEALTH CONTEXT CHANGES, ALONG WITH TECHNOLOGICAL ADVANCEMENTS PRESENT A UNIQUE OPPORTUNITY TO REVISIT TRADITIONAL HAZOP SESSION TECHNIQUE, AIMING AT ITS CONTINUOUS IMPROVEMENT, SO UPCOMING RISK ASSESSMENT CAN CULMINATE IN MORE ROBUST AND TANGIBLE RESULTS. WE FIRST INTENDED TO GATHER PERCEIVED DEFICIENCIES OF THE WELL-KNOWN HAZOP TECHNIQUE, TO ULTIMATELY ENHANCE IT, BY PROPOSING AND TRIALING NEW MECHANISMS, AND COVERING GAPS BETWEEN THEORY AND PRACTICE. BASED ON EXPERIENCED HAZOP FACILITATORS’ AND ATTENDEES’ OPINIONS, RECURRING DEFICIENCIES WERE IDENTIFIED, NAMELY: PARTICIPANTS’ LIMITED UNDERSTANDING OF THE TECHNIQUE, LOW ENGAGEMENT, EXTENSIVE SESSIONS, UNPRODUCTIVE RISK CATEGORIZATION AND UNFRIENDLY PRESENTATION OF RESULTS. THIS ASSESSMENT OUTLINED THE BASIS FOR THE PROPOSED IMPROVEMENTS: FACILITATOR HIGHER ACCOUNTABILITY AND PREPARATION; VISUAL MEDIA TO PREPARE ATTENDEES IN PRE-SESSION, ALSO AN OPPORTUNITY TO COLLECT INDIVIDUAL ASSESSMENTS OF PERCEIVED RISKS THROUGH FORMS; OPTIMIZED SESSION TIME, USING DIGITAL TOOLS TO PRODUCTIVELY ACHIEVE CONSENSUS; RESULTS PRESENTATION IN A MORE INTUITIVE FORMAT, ALLOWING EASIER TRACKING OF FOLLOW UP ACTIONS. THIS MODIFIED HAZOP TECHNIQUE HAS BEEN PARTIALLY APPLIED TO AN FEL3 PROJECT IN MINING INDUSTRY, CONDUCTED REMOTELY. RESULTS SHOWED THAT PRE-SESSIONS HELPED PARTICIPANTS WITH LIMITED HAZOP KNOWLEDGE TO CONTRIBUTE, WHILE THE TECHNICAL REGISTER INDIVIDUAL FORMS ALSO LEVERAGED MORE CONTRIBUTION FROM EXPERIENCED COLLABORATORS. AS A RESULT, SESSIONS WERE MORE COMPREHENSIVE AND TIME-EFFICIENT. THE PARTIAL APPLICATION OF THE MODIFIED TECHNIQUE YIELDED SIGNIFICANT GAIN AND INDICATES THE POTENTIAL OF THIS TECHNIQUE FOR FUTURE STUDIES.

Abstract:

The Minas-Rio beneficiation plant was designed to concentrate low-grade itabirite. The flotation was designed to receive two flows that have different particle sizes. This difference in particle size between the 2 flows that make up the flotation feed increases the loss of iron by hydraulic drag. In this study, the alteration of the existing process route was evaluated. The studied proposal consists of making the flotation of coarse and the magnetic concentration of the fines and ultrafines feasible, eliminating the 2nd stage of desliming. Industrial samples were studied on a laboratory and pilot plant to show the gains of this proposal. The results showed that the proposed circuit is more efficient than the existing one. By implementing this circuit, the production gain is over one million three hundred thousand tons per year, resulting in a high financial return

Abstract:

Formation of a superficial oxide layer (scale) during the reheating of steel plates is inevitable. During the passage of the plate through the walking beam furnace, different variables can affect both the kinetics and the shape of the formed scale. The alloying elements present in the chemical composition of steel affect, through different mechanisms, the morphology of the generated scale, in general decreasing the kinetics of its formation and/or increasing the adhesion of the oxide layer with steel. This work evaluated the influence of Mn and Si on the scale formation in steels processed in a hot strip rolling mill. After passing through the reheating furnace, samples were analyzed using optical microscopy and scanning electron microscopy, including the determination via EDS of the phases formed and the presence of alloying elements. The results indicated the possibility of Fayalite formation, the appearance of porosity and the "delamination" mechanism. Such mechanisms are harmful to the quality of the material, and their occurrence is related to the adherence of primary scale.

Abstract:

The automotive industries use low-alloy steels in the manufacture of mechanical components for their excellent resistance to friction wear after heat treatment of tempering and tempering. AISI 4140 steel are classified as low alloy, have good hardenability and excellent core toughness. This feature makes it interesting for research. Among the various methods, cold plasma nitriding (NP) provides increased wear resistance to steels. For these reasons, AISI 4140 steel was heat treated by tempering and superficially hardened by plasma nitriding. The samples were subjected to the wear resistance test in a microabrasive system by free sphere. The thermochemical treatment enabled the formation of Mn4O and a diffuse layer of Fe4N with 110 μm of thickness with a maximum hardness of ~ 1000 HV. The diffusion of Nitrogen took place at a temperature of 340 ° C aided by alloy elements present in the steel and due to the presence of austenite retained in the tempered samples. Despite the formation of a nitrided Fe4N layer, the microabrasive wear coefficient did not improve in comparison to the only tempered sample. The results prove that in a wear system, hardness is not the only parameter to be evaluated to guarantee better results.

Abstract:

It was studied an industrial ultra-low carbon steel sheet, with additions of Mn, Al and Si, cold-rolled, box annealed and under a skin pass. From this condition, it was applied a thermal treatment, under laboratory conditions, in order to produce a fully processed electrical steel (TP) under box annealing conditions. Alternatively other thermal treatment was applied to reproduce the condition that manufactures use to fabricate semi-processed electrical steel (SP). It was observed that TP route showed worse magnetic properties due to the smaller grain size associated with less favorable crystallographic texture.

Abstract:

LOTO procedures preserve lives in all industrial segments. However, current procedures can be violated due to their manual and non-audit feature. This article will explore a solution created so that LOTO can be carried out in a procedural and supervised manner, decreasing the incentive to violate vital security procedures. The proposed methodology includes the insertion of new agents in the current process, such as, for example, software capable of managing the entire LOTO flow and automatic blocking boxes for key storage, with remote activation. The feasibility of the solution presented is analyzed based on a case study of its implementation in a multinational company, in Minas Gerais

Abstract:

Abstract:

In the production of pig iron is generated Blast Furnace Gas (BFG), a byproduct of high relevance for the energetic balance of steel plant. This work aimed to verify the possible causes for the clogging on the gas cleaning system of Blast Furnace 3, using six sigma methodology. The water piping had presented obstructions, demanding the replacement of the piping more often. After the evaluation of the Blast Furnace and Water Treatment Unit Systems, the control parameters and the operational procedures were adjusted minimizing the scale on the water distribution piping and Scrubber system.

Abstract:

Steel structural elements for the construction industry lose their mechanical properties considerably above 500C. Therefore, one of the ways to act in the fire prevention is to use thermal protection materials. Among the products available on the market, there are intumescent coatings. These materials when exposed to high temperatures expand forming a carbon layer with insulating properties. In this context the goal of this work was to develop 03 formulations of intumescent coatings to protect thermally metallic structures. Duplicate tests were carried on and compared to the results obtained in substrates without any coating. A coating thickness of 1.0 mm was applied over the substrates and the time to determine the fire resistance of the system was equal to 30 minutes. The swelling coating process showed satisfactory results in terms of thermal protection since the cold face temperatures recorded were below 230C. For the uncoated substrate, this value was 500C. The expansion values presented by the carbonaceous masses formed were above 650%.

Abstract:

SAE 1012 is a carbon (non-alloy) steel. It is easily workable steel due to its mechanical strength, toughness, ductility, weldability, and machinability. For these reasons, it is used in final multiple applications, mainly for metal profiles and tubes. In 2019, there was a degradation of the national carbon and alloyed steel market, with losses in profitability, due to the increase in the cost of raw materials, mainly iron ore. Using the tools Brainstorming, Matrix Effort x Impact, and 5W2H, a new opportunity was envisioned and prioritized by the team. The challenge was to produce hot coils of 1.8 mm and 1.9 mm thickness with good quality, yield, and productivity. The thickness aimed was below Steckel's nominal specification of Aperam Timóteo. Robust hot process standards have been developed with an emphasis on the thermomechanical cycle in Rougher and Steckel Rolling Mills based on high-performance cylinders (HSS) use. With the greatest project agility, after 3 months only, the product portfólio of Aperam was upgraded, including the prototyping milestone. An important order volume of Hot rolled SAE 1012 grade was added to the business portfolio, which was the pillar of maintenance of production levels in the plant's hot circuit. Based on the understanding of the fundamentals of the physical metallurgy of hot deformation, mainly hot mathematical simulation, a new phase of the development is ongoing aiming to expand the current portfolio, even more, mainly new thickness and new width in the Steckel mill product window

Abstract:

Abrasive cutting is the ideal cutting technology to increase the throughput capacity as well as the flexibility of hot rolling mills, mainly for long but also for flat products. A higher degree of automation reduced overall running costs and an improved quali-ty of the rolled products are as well substantial advantages of abrasive cut-off ma-chines compared to conventional cutting techniques. For that reason, new rolling mills, in particular for SBQ products, are equipped with abrasive cut-off machines. During recent years, also numerous existing rolling mills have been upgraded by ret-rofitting abrasive cut-off machines. To achieve best possible results, however, it is essential that the abrasive cut-off machines used are specifically designed and perfectly tuned to the individual application. Taking large-scale projects recently executed by BRAUN as examples, the concepts how the requirements of rolling mill equipment and rolled product are met are described.

Abstract:

Friction Stir Welding (FSW) is a solid state bonding process, which has been widely used and studied in recent years. In this work, it were evaluated the ductility, the yield (YS) and the tensile strength (TS) of the 7475-T7351 aluminum joined by FSW, obtained through uniaxial tensile tests at room temperature and at 300 ºC. To the microstructural characterization the stereoscope, optical microscope and scanning electron microscope were used. In the tensile test at room temperature the YS and TS were nearby, but there are indications that after the FSW these are higher, however, the inverse occurs for the hot tensile test. After the FSW there was a great ductility decrease in both tensile tests.

Abstract:

In the BOF converters are frequently problems due skull around lances. This a reason for many efforts and safety attentions. There were developed a special lance with special shape in copper to avoid this problem. Numbers are incredible in life and avoid lance skulls. With this new routine, operators and mainatence team didn´t inspect lance like in the past and some times huge skulls grow up around lance and make damages for movable hoods and lances. This papers show a virtual eye to inspect and measure the thickness of skull around lance every heat.

Abstract:

Tenova’s Intelligent EAF technology (i EAF®) provides a multistep roadmap for continuous improvement, cost saving and increased safety. A full i EAF®’ System is a combination of real-time measurements, using state-of-the-art technology and robust process models, including a precise real-time mass & energy balance; with the objectives to reduces operating costs while increasing yield & productivity; The i EAF® also represents a powerful, stable and robust process control engine for EAF Level 2 automation and it could be enhanced with the industry’s most comprehensive water leak detection using both H2 & H2O vapor analysis. This paper includes a technical description of the technology, applications and reference list and latest results

Abstract:

As part of the progressive renovation project of the steel plant facilities, Arcelor Mittal Tubarão has decided to proceed with the revamp of CCM#2 slab caster in Vitoria (Brazil), aiming to improve slab quality, increase productivity and widening at the same time the product portfolio. Focused on updating process and operation control with the full set of the advanced up-to-date Q-Technological Packages by Danieli Automation. Scope of work has been the complete renovation of the caster, with advanced mould (equipped by Q-WIDTH model) and oscillator, “tight roll pitch” segments for DSR application driven by Q-CORE model, fine and flexible control of slab cooling by Q-COOL model. The casting floor (ladle turret and tundish) have been kept unchanged as well as the evacuation area pass-line, with modernization of the downstream single machines. Mould fluid-dynamic has been deeply studied together both in CFD and water model test. The superior quality on strip surface is confirming the good design for SENs and achievements of the mould level control (Q-Level+), supported as well by in site measurements of meniscus behavior. In the present paper are described the relevant studies carried out, the achievements and the results for CCM#2 performances in terms of productivity and operation, as well as product quality.

Abstract:

This study aimed to make feasible the production of a low carbon steel in an electric steel shop for galvanized wire manufacturing. Six steels were produced based on the SAE 1005 standard: one steel produced at an integrated steel mill equipped with a basic oxygen furnace, one steel with boron addition produced at an integrated steel mill equipped with a basic oxygen furnace, one steel produced at an electrical steel shop, and three steels with different levels of boron addition produced at an electrical steel shop. These steels were used for production of galvanized wires BWG 12. The characterization of the steels and galvanized wires aimed to determine chemical composition, mechanical strength (tensile test) and strain ageing behavior. The results obtained indicate that the addition of boron in the production of steel in an electric melt shop considerably reduces the ultimate tensile strength and increases the elongation of galvanized wires, making them similar to those produced in integrated steel mills. These observations are even clearer for the steel with intermediate boron content. Under the conditions in which this study was carried out, it was observed that the production of low carbon steel in an electric steel shop for the manufacture of galvanized wires could be carried out with appropriate additions of boron in the steel composition.

Abstract:

A stable blast-furnace operation is strongly associated with the performance of tap hole clay, as a poor material could lead to an inefficient liquid drainage. Usually, tap hole clay is damaged due to the combined effect of slag corrosion and pig iron erosion, which has recently become more aggressive due to the use of cheaper raw-materials and low-cost operational practices. Aligned with such challenging scenario, Saint-Gobain developed a high-performance solution based on an innovative tap hole clay with a graphene-like structure, which guarantees an outstanding chemical resistance and, as a consequence, a stable and long lasting protective mushroom

Abstract:

Iron ore pellets are a high value-added product. The demand for this product is growing in the global market and high productivity is a critical factor. The discharge ramp is an equipment coupled to the pelletizing disc with the function of collecting the pellets formed on the disc and forwarding them to the process sequence. The maim problems found in the discharge ramp are the ore aggregation and abrasive wear. These phenomena cause maintenance stoppages, compromising productivity. This work evaluates different materials to minimize these problems through measures of adhesive energy and abrasive wear. The results do not clearly show a better performance among the tested materials. There is a discussion of other variables that should be analyzed

Abstract:

Studies on the reuse of iron ore tailings (IOT) have stood out in recent years, due to the increase of the waste volume and accidents that occur in tailings dams. Thus, this work aims to present the state of the art of studies related to the reuse of iron ore tailings in Brazil and to be used as a guide for future works that intend to find alternatives for the reuse of IOT. The results of the research showed that the main characteristics of the IOT that should be analyzed initially are granulometry and chemical composition. Therefore, applications for IOT can be estimated, such as in the production of artificial stones, geopolymers, ceramic tiles, and others. In addition, studies on the applications of IOT are not limited to civil construction, since there are already other alternatives that deserve to be highlighted, as in the production of supercapacitors for instance.

Abstract:

The study presented here had been to objective discuss about the influence of the residence time versus percentage of solids in the feed of stages of itabiritic iron ore flotation from Samarco Mineração. Using samples named of coarses, fines and ultrafines, collected in the industrial circuits and/or prepared in laboratory, was done kinetics flotation tests in two different scales. With the results, the evaluated responses variables were: grade of silica in the concentrate, grade of iron in the tailing, metallurgical recovery and Gaudin’s selectivity index – been these the some of major parameters in the concentration process. In pilot and laboratory cell, it was possible to affirm that a reduction of the percentage of solids to values below the industrial practiced [from actual 55 and 40%, depending on the circuit] brings greater selectivity to the process, with a reduction of grade of iron in the tailing and silica in the concentrate – even assuming a shorter residence time. If applicable at large scales, such alternative would allow a better use of the mineral resources and a less generation and/or discharge of tailings.

Abstract:

Maraging steels are extremely important for the industry, among the many possible applications of this material, there are some components of ultracentrifuges used for uranium enrichment. With martensitic microstructure and high content of alloying elements, it is common to use heat treatments to adapt the properties of the material to the specific use. It is known that the exposure of such steels to specific atmospheres and temperatures leads to the formation of surface oxides with spinel type microstructure, which can help in the corrosion resistance of the material. This research aims to study the influence of oxides formed after exposure of steels in a CO2 / H2O vapor atmosphere on electrochemical properties. The analyzes were performed using the techniques of Open Circuit Potential, Electrochemical Impedance Spectroscopy and Linear Polarization. The comparison was made with the samples without the oxide coating in the solubilized and aged conditions at 480ºC for 3 hours. The experiments were carried out in a 0.01M hydrofluoric acid solution.

Abstract:

The non-reflow tinplates (matte aspect) were produced in laboratory, in which an industrial electrolytic bath was used (methane sulfonic acid - MSA). Different electric current plating densities (10 a 60 A·dm-2) have been used to produce that sample, keeping other process parameters constant. The texture analysis showed, by electron backscattered diffraction (EBSD) via SEM, that there was a change on coating crystallography texture between densities 10 and 20 A·dm-2. The presence of preferential texture (001) and (742) has been observed in electroplated coating produced under the density 10 A·dm 2. In the range densities 20 to 60 A·dm-2 were identified the component (744) and (743). Preferential texture evolution involved planes with similar packing density values, which does not compromise the corrosion resistance of the material.

Abstract:

This paper studies the effect of manganese content (5, 8, 12, 15 and 18%) on the wear resistance and impact properties of Hadfield steels. Mechanical tests results showed that Hadfield steel with 15% Mn had the highest value of the impact energy (249J), followed by Hadfield with higher C and Mn content (1.4% C and 18% Mn, 201J), and the conventional Hadfield steel (12% Mn, 199J). Hadfield steel with 15%Mn presented the highest value of Hardness (HV30). In the rubber wheel abrasion tests, Hadfield steel with 8%Mn presented the lowest value of mass loss, followed by 12% and 15%Mn. Microscopic characterization of the fractured test-pieces indicated that higher Mn contents increased the proportion of plastic deformation by the twinning mechanism.

Abstract:

THIS ARTICLE PRESENTS THE STRATEGY ADOPTED BY ARCELORMITTAL TUBARÃO IN GENERATING A QUALITY INDICATOR FOR THE TRACKING PROCESS OF SLABS PRODUCED IN ITS CONTINUOUS CASTING MACHINES. FOR THIS, A SOLUTION WAS DEVELOPED WITH THE OBJECTIVE OF ALLOWING THE AUTOMATIC RECOGNITION OF PRINTED CHARACTERS EVEN AT HIGH TEMPERATURES, IN ADDITION TO SHARING THE INFORMATION COLLECTED WITH THE COMPANY'S SYSTEMS. THE SOLUTION IMPLEMENTED REACHED AN ASSERTIVENESS INDEX OF 86.26% IN PRODUCTION, CONSIDERED EXCELLENT GIVEN THE ADVERSE CONDITIONS OF THE PROCESS.

Abstract:

Due to an internal crisis of loss of productivity of productivity and risk of environmental impact, because of the concentration of cyanides in the effluent of the gas cleaning system of the Blast Furnace. This anomaly collapsed the water treatment systems. So, there was an investigative work to create control actions for the system. As a result of the data obtained during data collection, a cyanide level prediction model was developed, using regressions. The model obtained during the testing phase obtained results of R2 = 0.75.

Abstract:

The pulp and paper industry traditionally breaks down environmental problems due to the large amount of waste generated, of which stand out as biomass boiler ash and wastewater. An increase in ash as a real challenge, as it has erosive capacity and does not burn, requiring its own system for removal. This work aims to evaluate the feasibility of incorporating a red ceramic ash boiler. The raw materials were subjected to characterization tests, and compositions were prepared with different percentages of 0; 2.5; 5; 10 and 20% by weight of light ash in the ceramic mass. The ceramic specimens were pressed-shaped and fired at 600 to 1050ºC and subsequently the tests were technologically tested, such as: linear shrinkage, water absorption and compressive strength. Experimental results indicate that the eucalyptus light ash waste as positively influenced the technological properties of the red ceramic pieces. The results also show that between 5 and 10% in ash waste as a partial substitute of plastic clay allows the use of red ceramic products of excellent technical quality

Abstract:

Vallourec Soluções Tubulares do Brasil has at its site in the Barreiro region, in Belo Horizonte, a Wastewater Treatment Plant (WWTP) where occurs the treatment and recirculation of the water used in the industrial processes of rolling, heat treatment, cold drawing and threading. This plant has the second highest energy consumption among the energy and utilities facilities and is one of the biggest individual consumers at the Barreiro site. This paper presents the work of modifying the steps of water treatment within the station, using the DMAICS methodology, to optimize the consumption of electrical energy per cubic meter of recirculate, maintaining the quality required by customers.

Abstract:

The present paper aims to evaluate the flow inside the descaling header present at USIMINAS’ hot strip, as well as the influence of descaling nozzle designs on the water spray shape, through the computational fluid dynamics (CFD) method. For such analysis, the software Siemens NX Mach 12.0 was used for geometry modeling, followed by the use of Siemens STAR CCM+ 13.06.012 to perform the CFD analysis. This paper states that, during the process, there appears to be a pressure change inside the header, depending on the equipment length, along with water impinging on the nozzle’s filters that generate a turbulence within the system flow. The turbulence can negatively impact the water spray quality, whilst consequently descaling the process efficiency. Also noted, was the influence on how nozzle geometry is related to the water spray shape, such that the cone angle and the “pseudo” radios formed by these projections of nozzle holes. In conclusion, it is deemed acceptable to start a second stage of this project in order to analyze the spray influence in relation to the hot strip cooling and the surface impinging.

Abstract:

The products of interest in this work are helical springs for use in vehicle suspension. A work plan based on the combination of alloy design and processing route is proposed to maximize resistance to corrosion and hydrogen embrittlement associated with increased mechanical strength (tensile strength, impact resistance, and fatigue life improvement) through grain refining. It was possible to notice that despite the reduction in the carbon content of the alloys, it was possible to maintain the same level of yield stress compared with the alloy traditionally used for spring steels (AISI 9254) and increase the impact resistance by 500%. Due to the change in chemical composition in the proposed new alloys, it was possible to verify the significant improvement in the corrosion performance (15% better) of the different materials proposed, as well as resistance to hydrogen embrittlement measured by loss of ductility in the 3-point bending tests.

Abstract:

The use of rebar as structural reinforcement of reinforced concrete shows the relevance of these materials in many industrial sectors, particularly in construction and infrastructure. In this context, the rolling manufacturing allows obtaining a material with lower cost and considerable quality, according to the required specifications, remarkably when performing, in hot rolling, the Thermex heat treatment step, in which the improvement of the mechanical properties is obtained because of the microstructural transformations that occurred. These transformations also influence the corrosion resistance of the material, as the microstructural variations acquired by the heat treatment parameters can present different performances in terms of corrosion. In this work, the CA-50 rebar made of 1025 carbon steel was evaluated regarding corrosion resistance, whose interest was in the effect of Thermex on this property. Electrochemical analyzes such as Open Circuit Potential, Linear Polarization Curves and Electrochemical Impedance Spectroscopy were carried out, and with the solutions of 250, 500 and 1000 ppm NaCl, helped to define the main corrosion parameters. In addition, Vickers Microhardness measurements indirectly verified the microstructural transformations that occurred during the treatment. The microstructural characterization by Scanning Electron Microscopy, in its turn, in addition to identifying the phases formed after the treatment, also characterized the morphology after the corrosion tests, revealing the presence of generalized and localized corrosion. The techniques used in the routes with and without Thermex allowed us to highlight that the microstructure formed along the Thermex is decisive for the differences obtained in the characterizations, impacting on the corrosion resistance of the rebar.

Abstract:

Refractories have a great importance in the steel industry. Studies on the wear of refractories are not uncommon. These analyses are generally done by statistical methods, based in premises that can't always be achieved with industrial data bases. To avoid these assumption, computational methods, such as Artificial Neural Networks and machine learning, can be used. The present work provides a method for utilizing Self-Organizing Maps for feature extraction and variable selection in the wear of refractories in steel making ladles. A bootstrapping and stabilization evaluation were carried on, where it was found that 87.5% of the system's variables converge via SOM. The variable selection showed 80% similarity to the statistical method and could identify hidden features of the data. A linear regression model was created based on the variables selected via SOM, which was smaller and just as well fitted as the model presented in the previous work. This SOM based model also had a better sensibility analysis when compared to the statistical based one. It was concluded that the proposed method provides a good support for decision making when addressing the control and prediction of the refractories life without requiring knowledge from the process or large time and/or effort.

Abstract:

The paper presents a robotic workstation, which has been developed and installed in the steel shop of an Italian steel company, representing one of the first attempts to establish a collaborative environment where a robot supports the technical personnel in a complex and delicate maintenance operation. The purpose of the robotic cell is to support the inspection, cleaning and replacement operations of the refractory components of the so-called “sliding gate”, namely the de- vice allowing the liquid steel to flow from the ladle to the tundish of the continuous casting. The robotic cell includes a vision system supporting the different operations, and a Human Machine Interface, which facilitates the interaction between the robot and the operators and helps to improve the qualitative performance of the whole process. Within such a course, the sequence and new division of human-robot activities were thoroughly developed within an innovation process integrating the future users and operators (embedding technological innovation within a social innovation process). In the steel sector the implementation of human-robot cooperation is hampered and slowed down by harsh environmental conditions in some applications, as well as by intrinsic difficulties of some operations, which require a combination of force and precision and need to be supervised and acknowledged by the technical personnel due to strict safety regulations

Abstract:

Continuous casting is responsible for the controlled solidification of liquid steel. Solidification begins in the mold by the formation of a shell that supports the liquid core throughout the machine. The rupture of this shell represents one of the biggest problems in the continuous casting process. To avoid this problem, a Breakout Detection System (BDS) is used to continuously monitors thermal parameters through thermocouples strategically positioned in the mold. In the literature, the main failure mode is by shell sticking in the mold, however with exploratory data analysis, through control charts, it was possible to identify a peculiar failure pattern in the casting machines and to establish innovative criteria for the activation of BDS to reduce the casting speed and eliminate the risk of shell breakage. The probability to activate the new BDS logic is less than 1.82·10^-6, and this implies approximately 2 alarms per strand/month. This solution removes a point of vulnerability from the current BDS and elevates the casting machine on a new level of operational safety.

Abstract:

The environment in which a steel structure is built affects the durability of its components, vis-à-vis the corrosion indexes according to ABNT NBR 14643:2001 and EN ISO 9223:2012. Regarding steel tiles, the most effective protection alternative corresponds to the deposit of a metallic coating over the metal base. Depending on chosen material, multiple performances are possible face to the environment. In addition, mechanical parameters also influence durability, in special thickness and steel grade, which must be compatible with project premises. As such, this article presents a review on main coating alternatives available for steel tiles as well as minimum mechanical requirements to ensure well performance during its lifetime. Hence, Zinc-Magnesium-Aluminium alloy was found to be the best alternative in alkaline environments and, at the same time, thinner tiles, at most those with thickness less than 0,40 mm, are more susceptible to serviceability limit states due to their reduced effective flexural stiffness.

Abstract:

The regenerators are heat exchangers whose function is to preheat the air wich will be blown trough the Tuyeres into the Blast Furnace. Blast Furnaces, in their operation , generate gas at the top, their composition being relatively rich in terms of calorific value. The generated gas is used to heat the refractory stack in the regenerators. During the campaign can occur a problem in the proccess heating the air regenerators causing undersired variantions and consequently disturbances in the steel process.

Abstract:

The permeability in the indurating furnace is the main factor that ensures a better firing and, consequently, better physical quality of the fired pellets and lower thermal consumption. The size distribution of the pellets from the balling plant to the furnace influences the permeability of the bed in the indurating furnace. Given the difficulties in dealing with the granular flow of the pellets, there is a need for the development of a model that allows for predictions of flow characteristics on the furnace feed. In order to achieve this, a phenomenological model for the green pellets handling was developed and validated using the discrete element method (DEM). This new pellet handling model, which demands much lower computational cost than DEM simulations, allowed for the optimization of the pellet bed profile in conveyor belts and in the feed of the induration furnace, by changes in conveyor belt layout and speed.

Abstract:

For some years now, companies have been looking for and working with some situations that exceed the limits of their business. Social, environmental and ethical issues have led these companies to seek more rational and politically correct ways to resolve possible conflicts and, above all, to gain advantages before their competitors and customers. In this way, Sustainability arises and with it new concepts are introduced, such as Social Responsibility, Social Inclusion and Social Marketing. Aiming to verify the collective perception about Social Marketing as a competitive differential for a mining company, a research was carried out with a qualitative and quantitative approach, of an exploratory and descriptive nature, using the case study method. Social Marketing can be seen as a competitive differential that aims to favor the organization and its image before its stakeholders, whereas Social Responsibility is the form of management that is defined by the company's ethical and transparent relationship with all the audiences with which it is involved. Relationships and the establishment of business goals that drive the sustainable development of society. Social inclusion offers equal opportunities for everyone to access goods and services. The results show that people are still unable to see the use of Social Marketing as a competitive advantage and that Mining companies have used this concept in a very limited way

Abstract:

Principal component analysis (PCA) is a multivariate analysis technique used to analyze relationships among a large number of variables to dimensionality reduction of a dataset into a smaller set of variables with minimal information loss. In this paper, PCA was applied using the RStudio program to evaluate the feasibility of the technique to facilitate flotation performance analysis in an iron ore processing plant. The dataset was obtained through a routine sampling during two months of regular operating period. It was analyzed original variables of chemical and particle size analysis and calculated variables, such as mass and metallurgical recovery. It was possible to reduce seven original variables to two main components. The two components together explain about 60% of the total variability of the data. The first component explains about 33% of the variance and is related to the efficiency of the process. The second component explains around 27% and is correlated with the selectivity of the process. The results show that principal component analysis is an effective technique for application in real flotation circuits, as it facilitates the interpretation of performance data and allows more assertive decision-making to improve process efficiency in the operational routine.

Abstract:

Corrosion is the most recurrent pathology in reinforced concrete, responsible for high costs in the recovery of the affected structure. In addition to direct costs such as materials used in the recovery, specialized labor, replacement of affected parts or equipment, there are indirect costs such as the suspension of use of the structure, loss of products such as oil, solutions, gas or water, loss of efficiency and product contamination. Finding ways to combat and prevent corrosion is extremely important. Cathodic protection has been presented in recent decades as an effective way to combat corrosion, not only stopping the corrosive process completely, but also preventing the appearance of new points. Its use has been increasingly applied in reinforced concrete structures, such as bridges, piers, industrial and residential buildings and tunnels. This article presents the computational program GCPCalculator developed for the design of galvanic anodes for steel protection in reinforced concrete, and also presents the design of the cathodic protection system for a column using the program. The results obtained are presented and discussed in this article.

Abstract:

The development of conductive inks containing metallic microparticles has gained evidence in recent years for applications in the semiconductor industry. In its composition, copper or silver particles are generally used, however, the high cost of silver and the oxidation of copper are limitations to produce of conductive material. Therefore, this work developed and characterized a conductive ink based on copper particles covered by silver (Cu-Ag) to overcome both disadvantages of pure metals. The morphology, size and composition of the particles were evaluated, and the electrical, physical and chemical characteristics of the ink were determined. The Cu-Ag particles showed irregular morphology with an average diameter of 4.54 µm. The ink showed pseudoplastic behavior and electrical resistivity in the order of 10-04 Ω.cm when sintered from 150 °C, in addition to excellent adhesion to flexible substrates. The results show that the ink obtained can be used in the area of flexible electronics, offering solutions by both spray and screen printing

Abstract:

This paper is focused on electrical vehicles. Some aspects of their history and market evolution is presented. Nowdays the electrical vehicles have almost 2% of car world sales, concentred mainly in developed countries. Some characteristics of electric vehicle motors are cited and is emphasized that electric steels applied to motor cores need to have specific requirements which are high magnetic permeability, high saturation induction, very low core loss, adequate mechanical resistance and good punchability. Finally it was mentioned that the world's leading steelmakers already offer steels with all the requirements suitable for electric car motors

Abstract:

Clogging of submerged entry valves in the continuous casting process increase the frequency of interruptions in operation. These interruptions increase operating costs and can cause a variety of quality problems. The absence of data sets labeled for clogging has prevented the application of machine learning methods for predicting this anomaly. This work sought to develop semiautomatic techniques for labeling reference data sets. As a first step, a clustering technique was applied over time series using the DBSCAN algorithm. The generated clusters were used as seeds for a semi-supervised label propagation process.This process generated a database that was validated by specialists where the data labeled as clogging were considered correctly labeled.

Abstract:

In the second half of 2020, CSP - Companhia Siderúrgica do Pecem experienced an internal crisis of loss of productivity and risk of environmental impact, due to side effects of the increased concentration of cyanide in the effluent from the blast furnace. This anomaly collapsed the internal effluent treatment systems, making it necessary to use the effluent to extinguish the coke as a means of disposal. The salts contained in the water caused a loss of coke physical quality, which generated instability in the blast furnace process, resulting in loss of production. Given this scenario, the CSP needed to implement an investigative process map in order to establish actions for control. The MASP methodology was applied based on the chemical analysis of the gas washing water for the cyanide element in the free and complex variations, considering different blast furnace operation scenarios. The results of the analyzes promoted the determination of the parameters that exert the greatest influence on the occurrence of the anomaly, making it possible to establish a correlation with the operating modes of the blast furnace. The completed process map allowed the CSP to establish a predictability analysis and control of this Anomaly

Abstract:

The steel industry continuously seeks technological and operational alternatives to increase the energy efficiency of the equipment. Several papers relate heat conservation as a fundamental element for this process. Following this trend, since 2016, the lining of Usiminas reheating furnaces in Ipatinga, which traditionally consisted of refractories from the Al2O3-SiO2 system, has been replaced by refractory ceramic fiber blocks. In this context, the methodology for the characterization and evaluation of the insulation capacity of the proposed lining is presented in comparison to the commonly used. The optimization of these furnaces through the new insulation technology proved to be efficient and the gains were expressive in terms of reducing heat loss through the walls, energy gain, preserving the metal shell and increasing the availability of equipment for operation. Additionally, a post mortem analysis of the proposed lining was carried out in order to assess the behavior of the fiber on an industrial scale.

Abstract:

The technological upgrade of 130 t/h nº 2 boiler, at Usiminas, took place in 2020, with main objective of updating the thermal exchange equipments and protection/control systems. This boiler, model VU 50 B, was built in the 70s, and it is one of 3 boilers that set Usiminas' Thermoelectric Plant 1, responsible for supplying steam for turbomachinerys, which blows air to Blast Furnace 3, and generates safety electricity for prior loads at Usiminas. This technological boiler upgrade leaves a significant improvement in operation and safety conditions, following standards such as NFPA 85, NBR 12313 and ASME VII. This constant search technological upgrade, with an emphasis on employee and process safety, demonstrates that Usiminas is aligned with the ESG (Environmental Social and Governance) concepts

Abstract:

The use of heavy plates resistant to hydrogen induced cracking in sour service applications has become fundamental to satisfy the greater demands that are required worldwide in the works and facilities of large diameter pipes. The industrial production of heavy plates is continuously being refined from the steelmaking process to hot rolling, through special techniques of mechanical and microstructural characterization. This paper shows the main metallurgical concepts that are established in product specification engineering; in the definition and optimization of the parameters of the steel production process in the melt shop and the rolling of thick plates; and in the detection and analysis of cracks and internal defects arising from the presence of hydrogen, in order to optimize and make economically viable the full production chain.

Abstract:

A new combination bar, bar in coil and wire rod mill has recently been commissioned at YongXing Special Stainless Steel Co. Ltd. In Huzhou City, China. The mill is designed to produce 250,000 tons per year of stainless valve steels, nickel-based alloy steel and numerous stainless grades, including austenitic, ferritic, dual phase and hardening steels. The new rolling mill, supplied by Primetals Technologies, has capabilities for rolling wire rod in sizes 4.5 – 16.0 mm, bar in coil from 16 – 40 mm and straight bar from 30 – 130 mm. The equipment includes quenching and heat treatment facilities to maximize in-line processing, plus new innovations such as stepless coil reforming for wire rod and optical bar counting for straight bar products, all selected to deliver higher grade stainless products. As production in the new mill continues to increase, YongXing is able to meet demands of customers seeking special grades for applications in the nuclear, automotive and petrochemical industries, among others, affirming their position as a top stainless steel supplier in China. This paper presents several equipment and process innovations incorporated into the new mill design and examines the initial results.

Abstract:

The gap in the market for measuring systems for hot rolled strip under tension has now been closed with a new product developed by SMS group and brings the proven X-Shape technology, which is based on the world market leading BFI flatness measurement concept, to the hot rolling process. In cooperation with VDEh-Betriebsforschungsinstitut (BFI) and ArcelorMittal, the prototype has been successfully installed and operated at ArcelorMittal’s hot rolling mill in Eisenhüttenstadt. The measuring system offers a detailed insight into the effects of flatness in the finishing mill when rolling with tension, as well as the effects of the laminar cooling

Abstract:

The steel ladle is fundamental to the secondary refining process. The refractories used must be designed to obtain the lowest specific consumption and the lowest possible interaction with the metallic bath. Currently, a lining with carbon (C) in chemical composition is used in the barrel of the steel ladle. The main goal of this project is to increase the performance potential of the barrel, proposing a tempered alumina-magnesia and carbon-free brick. This product has superior raw materials compared with the standard one and better compatibility with the current plant production process. The additional benefits of this new concept aim for steel quality, preservation of equipment, and savings in production costs. Another advantage of this product is the formation of the spinel phase at the hot face of the refractory, promoting brick-joint closure and minimising the metallic infiltrations within the lining.

Abstract:

Digital transformation is the industrial revolution of our age. A number of tools and services are now available to increase productivity, improve safety conditions, control and optimize the environmental impact (energy utilization, emissions etc.), train operators and keep track of all aspects of the production cycle. iMeltShop™ is a complete system developed to allow electric steelmakers to embrace this revolution. It consists of a complete suite of tools that enable scrap recognition and tracking, the optimization of EAF charge, the monitoring of all melt shop equipment conditions, an online production optimizer able to re-program the production schedule in to continuously optimize operations in case of unforeseen events. The utilization of artificial intelligence and algorithms developed in steelmaking environment give tangible results. All equipment in the plant can be monitored using video cameras without the need of installing new sensors. These allow, for example, ladles recognition and maintenance management or monitoring of continuous casters resulting in safer and cheaper maintenance cycles, without modifying equipment installing additional sensors. In addition to IoT and artificial intelligence, robotics contributes substantially to the digital acceleration: Tenova and Polytec partnered to create robotics solutions now installed in many EAFs around the world. The innovative robotic cell developed (and patented) allows the automatic sampling of steel temperature and composition and the video inspection of the inside of the furnace. These pictures and videos can be processed by artificial intelligence algorithms to predict potential failures and calculate the erosion of the refractories. Other dedicated robotics solutions allow the operations and maintenance of the EAF tapping, thermo cameras at tapping can detect the presence of slag in the stream and therefore regulate automatically the EAF tapping without the need of human interaction. Robotics has also been extended to other applications, like LF/VD sampling and management of continuous casters (snorkels installation, powder distribution, steel sampling in tundish etc.). The benefits of digitalization extend beyond the melt shop to the rolling mill, tracking all inventories from casting to rolling mill to the finite product warehouse, to the final customers. Tagging robots can label casted products and finished products with dedicated labels which can be tracked in warehouses.

Abstract:

SMS Group has made available to the Brazilian market coating technologies that can be applied in molds for continuous casting, among others. The coatings deposition offered takes place through the HVOF process - “High Velocity Oxigen Fuel”. The UniGuard coating deposited in continuous casting molds has been shown to be more efficient than Nickel in terms of abrasion resistance and durability. The greater durability of the UniGuard coating compared to nickel coatings leads to a lower consumption of raw materials and energy, thus being a positive factor with regard to the environment.

Abstract:

We requested an alloy from the Gerdau Mill for samples of DIN 16MnCr5MOD. steel, half of the standard samples and half with the addition of microalloys. Combinations of microalloys can be added to other steels, depending on the need for core hardness, however, the study focuses on the DIN 16MnCr5MOD alloy. Studies show that steels with the addition of NbTi refine and stabilize grain growth even after hours of heat treatment cycles, increasing fatigue life and reducing deformation

Abstract:

A stable blast furnace operation leads to a favorable drainage of pig iron and slag. The hole of the tap hole mix in this process is to assure stable values of tap hole length and casting time as well as injection pressures suitable to the process. The tap hole mixes in the Brazilian market comprise liquid tar as the binder, which presents a wide range of polycyclic aromatic hydrocarbons (PAH) which can affect the human health when there is an excessive exposure to its volatiles. TERNIUM BRASIL, aiming at increasing its sustainability level both in its processes and used products, teamed up with Saint-Gobain to develop a green solution to replace the tar-based tap hole mixes by focusing on an ecological binder with low levels of harmful elements.

Abstract:

The iron ore pellets, during the reduction in ironmaking, suffer crystalline and structural changes of great magnitude, which cause internal stresses in the ferrous oxide crystals and slag phase. Thus, to a greater or lesser extent, depending on the properties and quality of the pellets, the phenomena of swelling (volume expansion) and disintegration (generation of fines) occur. Swelling and disintegration are undesirable, as they cause disturbances in the flows of materials and gases within the reduction reactors, and negatively affects the productivity in ironmaking. This paper presents some conceptual aspects that are responsible for these phenomena.

Abstract:

The poor quality of iron ore, beyond the social and environmental issues require innovative and sustainable ways to reuse materials considered passive. Therefore, this work presents an analysis of the methods currently used for drying tailings from iron mining. As can be seen throughout this document, the great difficulty to dry this material is related to the pressure and temperature necessary to reach the essential moisture for the use of the materials in subsequent steelmaking processes.

Abstract:

The design os experiments, known by the acronym DOE is used frequently in the industry. The present study used the daily control parameters of the industrial flotation process of willemite factors of different levels for the DOE and the results of concentrate and tails contents as response variables. Thus, a predicition model was created, based on a regression equation, wich simulates the impact of changes in operating parameters on the grades analyzed. It is observed the influence of the factors in relationt to response variable and the interaction of factors witch each other. All tools were applied using MiniTab software. Through the results presented, it is concluded that it is possible to use the DOE tool to assess the impact changing the value of factors on the response variable using the parameters measured in the industry. The assertiveness of the prediction model is 95% in the confidence interval for the mean and equality between variances is obtained showing and adherence to trends in the operation.

Abstract:

The inhibitory performance of the flavone derivatives: 5,3'-dihydroxy-7,4'-dimethoxyflavanone and 5,7-dihydroxy-4'-methoxyflavone were investigated as corrosion inhibitors using functional density theory (DFT). The calculated quantum chemical parameters correlated to the inhibition efficiency are: the highest occupied molecular orbital energy (HOMO) and the lowest unoccupied molecular orbital energy (LUMO), the energy gap (EL-H), ionization energy (I), electron affinity (A), absolute electronegativity (), absolute hardness (), absolute softness (), the fraction of electron transferred (N), local reactivity was analyzed using the Fukui function and the local softness indexes, in order to compare the possible nucleophilic and electrophilic attacks. The success of DFT calculations in predicting inhibition efficiency was assessed

Abstract:

This work presents the main characteristics obtained after plasma nitriding of nodular cast iron type GGG70, with predominantly pearlitic structure and hardness of 303 HV0.05. The samples were nitrided under pulsed plasma process with a gas mixture 75%N2:25%H2 for 20 hours at 500ºC. The nitrided surface consists of compound layer growing in the outermost region of the surface and is followed by the diffusion zone in the matrix. The compound layer is clearly defined by metallography and has particular growth characteristics according to the phases present on microstructure of the cast iron matrix and exposed to the nitriding surface. The compound layer reaches a thickness of 10.8 µm and a hardness of 1037 HV0.025. The diffusion zone, not evidenced metallographically, was characterized by transverse hardening profile and present maximum hardness of 644 HV0.05 with depth of 0.14 mm.

Abstract:

This work proposes an optimization algorithm for the steelmaking and the continuous-casting (SCC) scheduling problem to manufacture billets, blooms, and slabs, which is a real hybrid flow shop NP-hard problem with continuous-casting at the last stage. This study considers the scheduling problem with diverse products and different casting times, which is a critical and challenging problem in steel plants. The algorithm is decomposed into two subproblems (primary and secondary problems) according to the nature of the SSC constraints and objectives. The proposed algorithm has been implemented on a GERDAU steel shop in Ouro Branco/Brazil, and it has been tested in several real-world scenarios, demonstrating to be a reliable tool for decision support and operational planning.

Abstract:

Among ferrous materials applied for wear, it’s the Hadfield manganese steels. Such materials present high toughness and wear abrasion resistance simultaneously, which leads it to become well accepted for mining, rail and recycling businesses. The target is to evaluate the effects of manganese and chromium contents on work hardening by impact of this alloy. It was evaluated three different chemical compositions, varying the percentage of the mentioned elements. Alloys were characterized by optical microscopy, scanning electronic microscopy and profile of Vickers microhardness. Obtained results evidenced the chemical compositions presenting higher percentages of manganese and chromium produce higher surface hardness after work hardening, being manganese the more relevant element for that. It was demonstrated at the same time that steels with standard chemical composition, given by ASTM A 128 presenting lower chromium percentage, presented higher deformation with lower surface work hardening, being this behavior linked to the mechanism of plastic deformation and chromium contents.

Abstract:

VAT46® alloy has great application potential in engine valves, where it is mandatory that the alloy has good mechanical property and high temperature corrosion resistance. In other alloys commonly used in valves, two factors influence both the process and the type of oxidation: the phase δ and water in value state. In VAT46®, being an alloy in development stage, there is still not enough data about the influence of the water vapour presence during the oxidation process and if the phase δ influences the type of oxidation and the oxides nucleation. Therefore, two specimens were oxidized, one with phase δ and the other without, in different environment: one dry and the other one with water vapor, for 10 hours, a period sufficient to analyze the influence of phase δ and water vapor in the oxidation initial stage. For the experimental purposes, the furnace utilized made it possible to control the pressure and the environment chemical composition, and for the analysis of the results, an electronic scanning microscope and X-ray dispersion spectroscopy were also used. The data indicate a variation in the oxidation rate with the water vapor presence and the preference for oxide nucleation in distinct regions from those rich in phase δ.

Abstract:

Corrosion affects the integrity of the material in an irreversible manner and affects the company’s use due to a gradual decrease in the availability of equipment and facilities. For this reason, in search of evaluating the perfomance of materials imposed to favorable conditions of service the occurrence of the phenomenon of corrosion, laboratory tests of accelerated corrosion are the state of the as they represent standardized and replicable conditions allowing an evaluation to be made after a short period of testing. In this context, the present work aims to consolidate a project made following the standard of ISO 9227, ASTM B 117 and DIN 50 021 allied to technical visits with searches on websites and catalogs added to the ABNT NBR 8094 standard. Therefore, specimens acquired together with PSA were exposed to a Salt spray fog chamber in a period of 48 hours, once the tests were done proved the chamber projected was effective and all the mass losses recorded were within the established by the standards parameters.

Abstract:

The comprehension of how protected metal surfaces behave on critical environments is highly necessary in order to understand and predict corrosion and estimate the effect cicle of life of coatings. The use of salt spray tests (NSS) according with ASTM B 117 standard is extensive applied in industry to assess the corrosion resistance of coated Materials. The NSS test aims to replicate environmental conditios such as humidity, temperature and chemical compositions around samples that would be subjected to agressive service conditions known to corrode metallic specimens. In this context, the present work has projected a salt spray gerating equipment folowing the ISO 9227, ASTM B 117 and ABNT NBR 8094 standards, the last one being mainly based on the latest standard. It proved functional, besides having a better cost benefit, in addition for solving all problems a planning inspection routing was made.

Abstract:

Corrosion behavior of one carbon steel and three weathering steels with different alloy contents in simulated marine and industrial atmosphere has been studied by accelerated corrosion test and field test with intermittent spray. The steels were subjected to 6, 15, 30, 45 and 60 cycles in accelerated tests, each cycle lasting 7 days and the field tests were carried out over 3 years. Increasing exposure time led to a decrease in corrosion rate due to the formation of a protective layer on steel surface. The corrosion rates calculated for carbon steel were higher than those of weathering steels, enhancing the relevance of Si, Ni, Cr, Mo, Cu and P in the formation of an adherent and compact rust layer. Results indicated that the additive Si in weathering steel led to improved performance during the corrosion process, especially in marine atmosphere. Cyclic corrosion tests highlight the importance of alloy elements such as Ni, Mn and Mo in the rust layer resistance in environments containing SO2. Field tests indicate that the weathering steel with higher amount of Ni, Mn and Mo obtained the lowest corrosion rates.

Abstract:

The influence of the applied potential and the concentration of chloride ions on the determination of the critical pitting temperature (CPT) of UNS S31803 duplex stainless steel (DSS) by potentiostatic polarization technique was studied. Applied potentials for the potentiostatic polarization tests (between 300 and 800 mVAg/AgCl) were chosen among a passive common range observed in potentiodynamic polarization curves obtained for chloride ions concentrations from 0,3 to 5 M, at room temperature. The determination of CPT under lower applied potentials and chloride concentrations showed higher dependence of chloride concentration and applied potential. CPT with the smallest dispersion of results were obtained around 50 °C under the most aggressive conditions, and CPT can be considered chloride ion concentration and potential independent under specific testing conditions: 600 mVAg/AgCl at 5 M NaCl, 700 mVAg/AgCl at 3 M NaCl or 5 M NaCl and 800 mVAg/AgCl.

Abstract:

Corrosion is extremely harmful to the material, causing major damage. Once undetected, it can cause an abrupt rupture of a part, structure or pipe, causing serious accidents. In order to reduce these damages, materials with chemical composition and suitable microstructures were created to be more resistant to corrosion. This is the case of stainless steels, which have the characteristic of containing at least 10.5% of chromium in their composition. This type of steel has a better performance when compared to common steel when applied in more aggressive media, such as in the petrochemical industry where it is widely used. In order to attest its resistance and evaluate its behavior in the presence of acid solutions, this work was developed using the duplex stainless steel UNS32304 which was subjected to two types of acid solutions, sulfuric and hydrochloric acid, in different concentrations. The immersion test lasted 60 days and had pH and potential difference measured weekly. Through the data obtained, it was possible to calculate the corrosion rate of stainless steel, evaluating its behavior and susceptibility to corrosion. It was concluded that the UNS32304 duplex stainless steel showed satisfactory results, with a rate below 5mpy in the different solutions, therefore, its use is recommended.

Abstract:

VAT46® alloy has been recently designed and has been shown to be effective for application in components working in corrosive environments. The chemical composition of the alloy categorizes it as a nickel-iron alloy, or intermediate nickel alloy. As with many alloys in this category, VAT46® precipitates the δ phase after undergoing heat treatment, as does IN718 (UNS N07718), for example. As it is an alloy in development there is no specific data on the characterization and metallographic preparation, and this is a procedure that helps the next researches on this alloy. Specimens have been used in two different conditions: A and B. The condition B has phase δ in the microstructure, and the phases γ' and γ" are presented with a coarser morphology compared to the specimen in condition A. The specimens passed through five steps of characterization and the last one was analysis in OM and SEM. The results indicate that the presence of phase δ and morphology of γ' and γ" coarser influence the performance of the reagent.

Abstract:

The present work evaluated the influence of the plasma nitriding treatment on the resistance to microabrasive and erosive-abrasive wear of AISI H13 steel. Nitriding was carried out in two conditions: the first, with a gaseous composition of 20% N2 and 80% H2 for a temperature of 440ºC, and the second condition with 50% N2 and 50% H2 for a temperature of 500ºC. The treatment time was 3 hours for both conditions, and the applied pressure was 2.5 Torr. The properties of the nitrided layers were analyzed by means of metallography, x-ray diffractometry and wear tests. In order to evaluate the resistance to microabrasive wear of different surface treatment conditions, free rotating ball microabrasion testing equipment is used. For the study of erosion-abrasion wear, the tumbler impeller tribometer (TTI) was used. In both wear tests, it was found that all the nitriding conditions studied promoted an increase in the wear resistance of the nitrided material in relation to the non-nitrided material.

Abstract:

Titanium alloys have been applied in aeronautical components mainly due to their high strength weight ratio. Yttria-stabilized zirconia (YSZ) of thermal barrier coating systems (TBC) applied by air plasma spraying (APS) increases the lifetime of turbine blades by providing higher operating temperatures. Laser modification of YSZ layer is a technique that has been investigated to enhance the properties of components with TBC. This work evaluated the creep behavior of Ti-6Al-4V alloy with CO2 laser remelted plasma sprayed thermal barrier coating. Creep tests were performed at constant temperature and load in the range of 500 to 700 °C at 125 MPa. The microstructure and fractography of the specimens were also investigated. The stationary creep rate at 600 °C reduced by 50% and the creep rupture life increased by 20%, which can be associated with greater oxidation resistance and thermal protection. Typically ductile fractures formed by equiaxial dimples were observed. In a region close to the fracture, it was observed a dual phase (α+β) equiaxed microstructure homogeneously distributed.

Abstract:

The processing of materials with laser is an alternative to form dense layers and porosity-free, as required by the metallic layer in the TBC application (Thermal Barrier Coating). TBC is a system of layers that promote protection against oxidation, corrosion and thermal protection of metal alloys, such as titanium alloy (grade 5). The aim of this work was to study the micrograph formed between the NiCrAlY metallic layer and the Ti-6Al-4V alloy by Yb-fiber laser processing. The metallic layer was pre-deposited in the powder form and submitted to the laser, whose beam scanning speed parameters were varied in 25, 50 and 100 mm/s with laser beam power of 200W with 50% of superposition for each track. The evaluation of the laser parameters was composed by scanning electron microscopy (SEM), x-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDS) in cross-sectioned of the sample. The results showed that there was adhesion between the NiCrAlY layer and the substrate with low chemical dilution at the interface. As the scanning speed of the laser beam increased, thinner metallic layers were formed.

Abstract:

Adhesion is the main property of mortars. The adhesion between the materials occurs mainly due to the transport of water between the ceramic block and mortar, generating an anchorage between the materials. The evaluation of the properties of materials that influence adherence are fundamental to better understand the complex system that involves adherence between materials. Among the properties that stand out for their correlation with adherence is absorptivity. Absorptivity measures the water absorption by capillarity of the ceramic block, which is the most representative absorption of the real mechanism that occurs between the materials. The objective of this work is to evaluate how roughcast influences absorptivity. The ceramic block will be characterized by tests of geometric characteristics, water absorption by immersion, resistance to flexion and absorptivity. The results indicate that the absorptivity is significantly influenced by the presence of the roughcast

Abstract:

The reuse of waste from various activities is fundamental in reducing the environmental impact. The incorporation of waste from the ornamental rock industry in the formulation of ceramic masses benefits both the ceramic industry, which has the potential to increase the performance of its product, and the ornamental rock industry, which generates the waste that finds purpose for its material, thus avoiding discard it. The objective of this work is to characterize and evaluate the incorporation of the diamond wire residue, material from the manufacture of ornamental rocks, for the manufacture of ceramic pieces. The characterization of the soil and the residue was carried out through the granulometry tests, real grain density and chemical analysis. After characterization, the specimens were prepared by extrusion with incorporations of 5,10,15 and 20%, in addition to the reference without incorporating the residue. After burning at 750 ° C, performance evaluation tests were performed. The results obtained indicate a better performance of the ceramic masses prepared with 10% of ornamental rock residue.

Abstract:

The characterization of clay deposits is essential to verify the feasibility of using these materials in the ceramic industry. Ceramic materials are widely used for the construction of walls and roofs of buildings. In addition to developing the local ceramic market, the manufacture of ceramic materials in the municipality of Jerônimo monteiro can absorb part of the ornamental rock waste generated in the neighboring municipality Cachoeiro de Itapemirim. The ornamental rock residue is already used in the ceramic industry after several studies identifying its benefits, however, the largest ceramic poles are located at a great distance from the pole of the ornamental rock industry. The objective of this work is to identify deposits and characterize the clays in the municipality of Jerônimo Monteiro to boost the local industry and contribute to the reduction of the environmental impact generated in the disposal of ornamental rock waste. A mapping of the region was carried out to identify deposits and clays were collected from five different points. For the characterization of clays, the tests of granulometry, real grain density, Atterberg limits and chemical analysis were carried out. The results indicate potential use of two clays from the region for use in ceramics.

Abstract:

Application of mortar over ceramic blocks is one of the main types of coatings used in Brazilian buildings. For an efficient coating it is necessary that the adhesion between the materials is adequate, however, the adhesion depends on a complex system with several variables. Among the variables that suffer from the empiricism of empirical executions, the wetting of the ceramic block can be highlighted. There is no homogeneity or quantification of how much the ceramic block is saturated before applying the mortar. The objective of this work is to evaluate how the saturation of the ceramic block influences the adhesion of the mortar coating. Absorptivity tests will be carried out to evaluate the water absorption of the substrates and water retention for the evaluation of the coating mortar. Three levels of saturation and two firing temperatures and application of a mortar with a 1:1:6 trace will be used. The tensile adhesion test will also be carried out to assess adhesion. The results indicate that the saturation of the ceramic block significantly influences adherence, in addition, the firing temperature also influences and interacts with saturation in a non-linear way

Abstract:

The development of the ceramic market encourages both the generation of jobs and the production of low-cost materials for buildings. Even though masonry is one of the main construction methods, the ceramic industry is not always able to meet the demand due to the great distances from the place where the material will be used and the place of production, which increase the value of the product. The objective of this work is to identify and characterize the clays in the municipality of Muqui-E aiming at the development of the local market, mainly due to the possibility of using waste from the ornamental rock industry in the neighboring municipality. A mapping of the region was carried out to identify deposits in addition to the collection of clays from four different points. Granulometry tests, real grain density, Atterberg Limits and Chemical analysis were performed for the characterization of clays. The results indicate potential use of a clay from the region for use in ceramics

Abstract:

The catalytic cracking process is conducted to convert less valuable heavy oils into more valuable and higher demand products. This is accomplished by breaking the long chains of hydrocarbon molecules in the FCC units. The process is carried out under heat, pressure and acid solid catalyst, in which the zeolites are the most used. As soon as the virgin catalyst is put into use, its activity begins to decline, mainly due to coking and contamination by heavy metals. Globally it is estimated that 1400 tons per day of spent catalyst are generated. This waste is treated as hazardous waste, and its disposition in a properly controlled landfill is not only costly, but it is the least noble alternative in the order of priority in solid waste management. A technical and economical solution to this scenario is the use of spent catalyst as a raw material for the ceramics industry. Thus, the objective of this work is to provide a technically and environmentally correct alternative for the use of the catalyst used as raw material for the red ceramic industry. Therefore, laboratory specimens were developed, involving the incorporation of 0, 5, 10 and 20% of residue by weight in a ceramic clay body for production of red ceramics, evaluated at the sintering temperature of 850 ºC. By means of technological tests, the technical feasibility of the incorporation of up to 5% of residue for the manufacture of solid bricks was verified, according to the standardized properties of water absorption and mechanical resistance

Abstract:

The aim of the study is to compare the effect of incorporating residues from different types of biomass into red ceramic. Clay formulations were prepared with incorporations of residues of coffee sludge, paper sludge, sawdust, sugarcane bagasse and water hyacinth are studied, in concentrations of 2.5%; 5%; 10% and 20% of waste, burned at 950ºC. Through the production of specimens, the values of the properties of linear shrinkage, water absorption and apparent porosity of each formulation were determined. Among all the formulations analyzed by this article, the one that presents the best result is the one that contains paper sludge. Its low linear shrinkage, water absorption within the Brazilian norm and relatively high porosity in the formulation with 20% residue, makes it a viable choice for making blocks used in acoustic sealing.

Abstract:

The work aims to evaluate the influence of different levels of residue on the physical and mechanical properties of a typical composition of red ceramic, which is marketed in Campos dos Goytacazes, Rio de Janeiro. The residue comes from the first stage of glass manufacturing in a conventional tempering process. Ceramic specimens were prepared with 0, 5, 10 and 20% residue incorporations. The samples were obtained by extrusion, dried and fired at 800, 900, 1000 ° C in a laboratory oven. Analyzes of the raw materials were carried out, among which the morphological, physical and chemical ones can be highlighted, and afterwards tests were carried out on the fired ceramic specimen. The firing properties obtained were dry bulk density, water absorption, linear firing shrinkage. The results obtained demonstrated that both the increase in the glass content and the increase in the temperature had positive effects on the studied properties, and, in addition to that, the glass acted in order to lower the appropriate firing temperature

Abstract:

In the present work, the objective was to evaluate the feasibility of developing a veneering ceramic using as material a clayey ceramic mass with incorporation of flat glass residue. Two masses were formulated, one with only clay mass, with 0% residue and the other with 20% flat glass residue. Specimens were prepared by uniaxial pressing at 12.5 MPa and subsequently submitted to the firing process at temperatures of 1000, 1050, 1100, 1150 and 1200°C. The raw materials were subjected to chemical, mineralogical and thermal characterization. The physical and mechanical properties such as linear shrinkage, water absorption, apparent porosity and mechanical resistance to bending of the burned specimens were evaluated. The reuse of flat glass waste in the ceramic industry can favor the reduction of the sintering temperature, generating better quality products. Based on the results obtained in this research, it was found that the residue added in 20% allowed samples that met the specifications for manufacturing porous coating (tile), making it possible to reuse it in the red ceramic industry

Abstract:

The increase in the number of cigarette butts thrown away daily improperly, and the lack of regulation for correct disposal, can cause pollution of water resources by heavy metals, as well as clogging of sewers. In this way, this work has the objective of removing incorrectly discarded bitumen daily, evaluating the feasibility of incorporation in the ceramic mass. Formulations with up to 10% triturated cigarette butts were prepared to the clay mass. After homogenization, the doughs were moistened and shaped by uniaxial pressing test specimens at 25MPa and burned at 900°C. The technological properties were evaluated for water absorption, linear retraction, and flexural strength. With the results obtained, it was possible to conclude that the incorporation of the residue is possible, but it should be in a weighted way, since higher percentages incorporated cause greater porosities to the pieces, leading to greater water absorption, and lower mechanical resistance

Abstract:

With the great advances in the industry, the generation of waste from different sectors is increasing. Therefore, a measure is needed to mitigate the environmental impacts generated by the incorrect disposal of these wastes. In this sense, new techniques have been studied for their use, through the incorporation allowed by ceramic masses. By adding controlled amounts, it is possible to obtain a final product that provides the properties required in its applications, this can be acquired due to the natural variability of clays. Dyeing plants generate, during their washing and dyeing processes, effluents that can be discarded in nature and a solid sludge that must be treated due to the presence of heavy metals from dyes and dyeing aids. The objective of this work is to evaluate the potential of the incorporation of dyeing sludge in red ceramics. After the characterization of the raw materials, specimens were made by varying the percentage by weight of the sludge. Burned at 850°C, they were exposed to different tests to determine their properties, such as linear shrinkage, water absorption and flexural breaking strength. It can be seen the need to control the sludge content in the compositions, however, once applied, it is possible to successfully obtain the properties required for ceramic products. Thus showing the effectiveness of the incorporation of the residue in question in the preservation of the environment

Abstract:

The Limnoperna fortunei – golden mussel is a mollusk of the bivalve class, which in this exploratory study has the complex microarchitecture of its shell as the target of our investigation. The objectives of this research are: to identify the mineral phases present in the shell using X-ray diffraction, to determine the hardness by the ultramicrohardness test and with the scanning electron microscope to visualize the existing layers. The mineral phases: calcite and aragonite were identified. The ultramicrohardness test was carried out on the innermost layer of the shell, the prismatic layer of aragonite, and the results found are consistent with the literature. Visualization of the periostracus, calcite layer, nacreous layer and prismatic layer was performed successfully. The results obtained allowed a better understanding of the analyzed material, which motivated us to deepen and advance in our studies.

Abstract:

One of the alternatives that has been studied to try to mitigate the impacts generated by the disposal of industrial waste in aquatic environments is phytoremediation. This decontamination process takes place through specific plants that are capable of absorbing / accumulating high concentrations of heavy metals. But as a consequence, the reproduction of these plants is very accelerated, thus generating a large amount of biomass, which in turn has to receive a correct destination because otherwise these metals return to the environment. This work aims to study the feasibility of incorporating this biomass in red ceramic. The survey carried out 0 incorporations; 2.5 and 5% by weight of biomass. Measure the dry bulk density, linear shrinkage and water absorption of these additions. And in the end we achieved positive results, being an ecologically correct alternative for the destination of this biomass.

Abstract:

The cement industry generates a large and varied amount of harm to the environment, however, studies have been carried out in order to mitigate such impacts, as sustainability is something that is very much sought after today, for the evolution of society and industry. This work sought to expand the knowledge about the incorporation of porcelain residues in the agglomerating fraction of the mortar, exploring the pozzolanic capacity of this very generated waste today. The research carried out experiments on mortars in the hardened state, without any incorporation, with 10% and 20% porcelain, observing properties such as resistance and water absorption that respond to the addition of the residue, and the results showed to be positive, thus being able to present a potential alternative the reduction of cement production and use, thus reducing the environmental impacts generated and producing positive impacts on the economy.

Abstract:

In the present of civil construction, the great demand for the application of Portland cement is evident. Knowing this and also its sources whose origins are exhaustible natural resources, the search for alternative materials with characteristics similar to Portland cement is of great importance. One of these materials is what we call by geopolymer. Agglomerating behaviors and characteristics such as Portland cement have been found in the geopolymer, with the potential to become an alternative to this. In addition, the potential of geopolymer is known to provide inputs with properties similar to those of traditional ceramic materials without the need for burning and high temperatures. Knowing this, in this work, the development techniques and the behavior of geopolymeric pastes prepared with sodium hydroxide and sodium silicate, as an activating solution, and commercial metakaolin, as a precursor material, were studied. After the 28-day curing period, the pastes were tested according to resistance, density, linear shrinkage, water absorption, and microstructure tests. The results show us that the paste that showed the most effective geopolymerization reactions and close to the desired behavior was the SiO2 / Al2O3 molar ratio of 3.0.

Abstract:

The development of cities culminates in great demand for services in the civil construction sector. As this sector is explored, more and more investment is being made in refining and improving existing techniques and services, as well as in the domain of new and more efficient materials for their execution. However, knowing that the civil construction sector is the largest waste generator in the world, more and more ends are sought for this waste in order to reduce the impact generated by the sector on the environment. In view of this scenario, the current research seeks the development of geopolymeric pastes with the application of glass waste, knowing the favorable chemical characterization of the residue to the geopolymerization reactions. In this way, pastes were developed and tested according to the tests of resistance to compression and traction in flexion, water absorption and porosity. The glass residue was applied to the precursor material of the mixture and showed improvements regarding the porosity and also favored the effectiveness of the geopolymer reactions when compared to geopolymer compositions with the absence of the residue. The results of its application are shown to be more effective in the 3,5 mole ratio compositions of SiO2 / Al2O3.

Abstract:

It is undeniable that the relevance of ceramic matrix composites (CMC) has grown in scientific and industrial circles. The combination of different ceramic materials allows to mitigate difficulties in manufacturing and processing or to improve the performance that each material would have in isolation. To investigate the CMC formed by silicon carbide (SiC), alumina (Al2O3), yttria (Y2O3) and glass-ceramics from the lithium-aluminum-silicon system (LAS), 6 samples of each additive were prepared regarding the weight percentage of LAS, 0, 1, and 5%. The material was dry mixed in a vertical mill for 1 hour. The mixture was pressed with 175 MPa, uniaxially, and sintered at 1800ºC. After sintered, the CMC was characterized by scanning electron microscopy (SEM) and Vickers hardness. For the application of Vickers hardness, the processing condition of the group with 1%w of LAS proved to be the best, with an average value of 25.11 ± 1.67 GPa.

Abstract:

The purpose of this article is to analyze the study of the thermal behavior of raw materials for ceramic tiles, through the use of pegmatite and shale residues, reducing the environmental impacts caused in the exploration of ornamental rocks. Therefore, this research started with the phase of preparation and composition of the samples, and then submitted them to the sintering test. After the physical tests, the results obtained pointed to the possibility of using residues for stoneware, semi-stoneware and porous, two formulations of different percentages (F1 and F2) being prepared. The specimens were sintered at 1050ºC, 1100ºC, 1150 ° C and 1200 ° C. According to ISO 13006, the formulations used at 1200ºC, showed characteristics for stoneware; F1 at 1150º showed characteristic of semi-stoneware, and F2 semiporoso; F1 and F2 both at 1100º | C had porous characteristics, and lastly F1 and F2 at 1050º had technical characteristics above porous.

Abstract:

Multiple mortar is a building material composed of cement, lime, sand and water. The main properties desired for this material are adhesion with the substrate and workability. Its use in civil construction is for block setting and for wall cladding. In this work, the addition of glass residue to the Portland cement was used on the 0%, 5%, 10%, 15% and 20% portions of the 1:1:4 trace (cement: lime: sand). The analyzed properties of the mortar in the hardened state were water absorption by capillarity, flexural tensile strength and compressive strength. It was observed that the mortar constituted with 15% of the residue presented significant results of resistance when compared to the other mortars tested

Abstract:

Brazil is one of the largest consumers of ceramic tiles in the world and one of the largest producers. Currently, the market is heavily in demand for red ceramic products. The state of Espirito Santo has stood out in recent years in the production of ceramic pieces aimed at the growing sector of civil construction. The northern region of the state has been standing out in the scenario regarding the production of ceramic artifacts. The objective of this work is to characterize clays in the northern state of Espírito Santo, and to evaluate their potential in the manufacture of red ceramics. Characterization tests were carried out by means of X-ray fluorescence, X-ray diffraction, granulometry and real grain density tests. The characterization results showed that clays have a great potential for the production of ceramic artifacts.

Abstract:

The main mechanism responsible for the resistance in red ceramic is the formation of a liquid phase through the presence of alkaline fluxing oxides. It is known that the clays in Campos dos Goytacazes, RJ, present deficiency of these components. Therefore, the objective of this work is to correct the alkaline contents of the raw material through the use of an alkaline solution. Test specimens were made by pressing 8% moisture in a 10M alkaline solution and fired at 400, 600 and 800ºC, and a control ceramic burned at 800ºC was also produced. The results of linear shrinkage, water absorption, porosity and mechanical resistance prove that the use of the alkaline solution allows to obtain more resistant compounds with better properties at 400ºC than the same specimens moistened with water burned at 800ºC. This characteristic allows savings to the ceramic sector, since the most expensive step for the sector is the stage of burning the specimens and reducing the temperature of the firing in half is a great economic advantage

Abstract:

Construction waste is problematic due to its heterogeneous characteristic, the large amount generated and the lack of recycling methodologies. Thus, the objective of this work was to use plaster plate residue from mortar as a substitute for sand in proportions of 0%, 20%, 40% and 60%, using a mortar 1: 1: 6: 1.5 ( cement: hydrated lime: sand: water), and carrying out tests of the hardened state of mortar, such as flexural tensile strength, compressive strength, mass density in the hardened state, water absorption and voids index. The results prove the feasibility of using 20% of the plaster plate residue, since with this percentage the material acts as filling in voids, improving the properties of compressive strength, for example. Levels of 40% and 60% are not viable due to the agglomeration of the residue within the cementitious matrix, which is why it is concluded that for recycling the residue without impairing the properties of the mortar, 20% replacement of sand by plaster plate residue should be used

Abstract:

The application of natural fibers, such as coconut fiber, is increasingly common in cementitious materials, such as concrete and mortar. However, there is still a need for more in-depth studies on the durability of these mortars. Thus, the objective of this work is to study the durability of mortars 1: 1: 6: 1.5 (cement: hydrated lime: sand: water), containing different percentages of coconut fiber (0%, 1.5% and 3, 0%). These mortars were tested for compression, where it was found that the use of the fibers significantly increases the strength of the mortar, being subsequently tested in wetting and drying cycles and degradation cycles in salt spray, checking the mass losses of the material and the drop in compressive strength after the cycles. It was found that the mortars containing coconut fibers performed better than the reference mortar in the wetting and drying cycles, but that there was a decrease in properties for the mortar containing 3.0% fiber in the salt fog degradation cycles due to fiber rot. However, mortars containing 1.5% coconut fiber showed superior performance in all situations, proving that the incorporation of coconut fibers in 1.5% is beneficial to the properties of mortars

Abstract:

The study of the properties of mortars in the fresh state, although neglected by some researchers, is extremely important to understand the performance of mortars. In this context, the objective of this work was to evaluate the properties of the fresh state, such as consistency, water retention, mass density in the fresh state and incorporated air content, in mortars 1: 1: 6 (cement: hydrated lime: sand), using the incorporation of gypsum residue from civil construction at levels of 0%, 20%, 40% and 60% as a substitute for sand. It was proven that the residue acts by reducing the content of incorporated air, and consequently increasing the density in the fresh state, and it acts by increasing the water retention and the need for water in the consistency test to maintain the same workability parameters, due to the nature hygroscopic residue. Thus, to maintain the parameters in coherent limits, defined by bibliographic consultation, it is possible to use 20% of civil construction plaster residue in mortars, proving the effectiveness of the assessment of the fresh state study and also the feasibility of applying the residue

Abstract:

The incorporation of residues in mortars faces a difficulty due to the lack of minimum normative values and due to different mortar compositions. Therefore, the objective of this work is to evaluate the incorporation of rock residue in 50% of substitution of sand in mortars of different compositions, such as 1: 1: 6 (cement: lime: sand), 1: 3 (cement: sand) and 1: 3 (lime: sand). It was found that the residue improves the properties of mortar regardless of the composition evaluated, as it causes a filling effect due to its fineness. In addition, it was found that cement-based mortars have the best parameters of strength and durability, while lime mortars have the best results of workability and water retention, while mixed mortars have an intermediate behavior. The viability of incorporating rock waste in mortars has been proven, regardless of its composition

Abstract:

At Companhia Siderúrgica do Pecém (CSP), the liquid steel that arrives to the continuous casting station to be turned into steel slabs, goes through the solidification process. However, not all the steel content of the teeming ladle becomes slab. In the interval between the steel arrival to the casting station to the moment it effectively becomes into slabs, some of the steel is lost in the process stages. The ratio between the steel volume that becomes slab and the volume of the liquid steel that arrives to the continuous casting is called continuous casting metallic yield. The yield loss in the Tundish is one of the main causes of metallic yield loss in the continuous casting. Therefore, understanding the causes and solutions for the metallic yield loss in this metallurgical reactor is of great interest to the steelmaking industry. At the end sequence in the continuous casting, a solidified steel mass, called tundish skull is discarded inside the tundish. It happens so to avoid vortex formation that takes place at a critical height above the tundish drainage nozzles . Votex produces entrapment of the steel slag and leads it to the mold. This event is both detrimental to the steel quality and to the process safety because it can lead to serious problems like strand breakouts in the continuous casting. Therefore, modify a metallurgical reactor like the tundish requires a great understanding of the correlations between the tundish and the liquid steel; the fluid flow behavior and the role of flow modifiers; the interaction between steel and slag inside the tundish; and the vortex formation phenomenon

Abstract:

In this work, a study of the formation of phases in alumina ceramics, doped with niobium oxide and hematite, using X-ray diffraction technique. of alumina with and without the addition of 4 %wt of niobium oxide and three variations in the content of hematite: 0.5, 1.0, and 2.0 %wt. Samples were prepared by uniaxial cold pressing and pressureless sintering. The X-ray powder diffraction results indicated the rhombohedral phase for both alumina and hematite, and the monoclinic structure for niobium oxide. In the sintered samples, three distinct phases were formed: AlFeO3, AlNbO4, and FeNbO4. The formation of these phases indicates the direct interaction of hematite with niobium oxide at high temperatures, forming the FeNbO4 phase. The AlNbO4 phase occurred due to the interaction of alumina with niobium oxide, and the formation of AlFeO3 occurred due to the interaction of alumina with hematite

Abstract:

With the large consumption of paper in Brazil and in the world, tons of waste are generated, which can affect the environment. In the papermaking process, a liquid residue with high levels of suspended solids is generated. Much of the waste generated is deposited in a landfill contaminating the soil. In recent years, industries have shown interest in the practice of recycling waste, mainly due to the requirements of environmental agencies. The civil construction industries have a great influence on the recycling of residues, for incorporating them in their materials, thus, several researches for the incorporation of residues generated in the manufacture of paper have been carried out. The ceramic industry stands out for being able to incorporate a large part of industrial waste, thus generating environmentally friendly materials. The objective of this work is to carry out a bibliographic review about the use of primary sludge waste in the incorporation of ceramic products, seeking an improvement in the final characteristics of the product as well as a sustainable disposal for the waste. In the light of the analysis of several authors, it can be concluded that the incorporation of primary sludge waste from the paper and cellulose industry is effective. However, waste samples vary from 2.5% to 10% of incorporated waste.

Abstract:

The process of manufacturing ceramic materials begins with the choice of raw materials and ends in the selection of the type of sintering of the parts. However, determining the percentage of each raw material that will make up a ceramic mass is a process that requires a great deal of technical knowledge. However, there are scientific techniques that are used to formulate the ceramic masses and bring greater reliability and accuracy in the properties of the final products, such as the triaxial method. In this technique the three main components of the ceramic mass are distributed in diagram in the form of equilateral triangle. In this way, having in mind the need of developing ceramic masses with adequate properties to meet the technical specifications and that the use of scientific methods to start the ceramic parts manufacturing process is indispensable, this work was idealized. Therefore, this work has as objective the production of ceramic masses, with regional raw materials, through the triaxial method. Six (6) ceramic pasta formulations were developed using as raw materials a white burning clay, potassium feldspar and quartz. The forming process took place in a hydraulic press with 21 MPa pressure, producing 15 samples of each formulation. The sintering of the samples was performed at temperatures of 1000°C, 1100°C and 1150°C, with a heating rate of 10°C/min and 60 minutes in a muffle furnace. The results show that the ceramic masses, produced through the triaxial method, have properties similar to the ceramic materials of the type coating.

Abstract:

The construction sector consumes a large volume of raw material, in the case of ceramics, clay, an exhaust resource. In order to achieve sustainable growth, in view of the high demands of incorrectly disposed sediments, ornamental rock residues are used, extracted by the movement of diamond wire, in the cutting procedure of a rock block, as an alternative raw material. The objective of this Scientific Research is to prove the durability of these parts, in addition to acquiring burning temperature, percentage of residue, considering atmospheric agents. For this, three lots were divided (Intact, Natural degradation, Laboratory degradation), in all there are 14 pieces made in each percentage of aggregate residue (OR; 2.5R; 5R; 7.5R and 10R), which were burned at three temperatures (750ºC, 850ºC and 950ºC). The intact batch was submitted to moisture cycles with saline water, under accelerated condition in the laboratory. While natural degradation will be exposed to atmospheric conditions, o Laboratory degradation has the purpose of rapidly presenting the natural changes. The parts the that make up residue obtained a decrease in the variation of linear measurements, and less moisture for ceramic processes. Thus, the incorporation of waste, besides being sustainable, ensures greater resistance to the parts.

Abstract:

Structural Health Monitoring (SHM) usually demands the use of sensors in large quantities and of high diversity, making use of this technique very expensive and complex. In this context Self-sensing Cement Composite promote monitoring without the installing sensors, by incorporating certain materials, which increase the electrical conductivity of concrete, so that electrical signals can be measured from effects such as piezoresistivity, its happen when the structures strain. To do piezoresistivity experiments, its necessary to know the techniques of measuring electrical quantities, that often requires a great familiarization with the subject, therefore there is reason to do didactic simulations usually contribute to the advancement of this domain. The Tinkercad platform was used to simulate electrical circuits applied to resistivity measurement, which confirm to be satisfactory for the proposed simulation, although some limitations were found in its operation, when compared to the results obtained through the software LISA.

Abstract:

Porcelains have pozzolanic potentials, so it is possible to incorporate them into the fraction of agglomerate in mortars. The cement industry generates a large amount of impacts on the environment, therefore, this work aimed to incorporate porcelain residue in the agglomerate fraction of mortars in the fresh state. One line without residue was produced as a comparative parameter and then two lines, one with the incorporation of 10% and the other with 20% porcelain. As a method of analysis, mass density tests were carried out in the fresh state, content of air incorporation, water retention and consistency. The results proved to be promising, due to an improvement in the required properties of fresh mortars. This incorporation of porcelain waste would not only mitigate environmental impacts, by reducing the use of cement and increasing the use of waste, it would also positively impact the economy

Abstract:

Fiber-reinforced composite materials have high durability, strength and less weight. Among them, polymers reinforced with fiberglass stand out for being difficult to recycle. This work aimed to discover properties of othophtalic polyester with a different composition by thermal analysis. Three different resins were used, like pure polyester (PP), another reinforced with fiberglass (PV) and a third composed of fillers and fibers with no defined origin (refuse) submitted to thermal analysis as DSC (Differential Scanning Calorimetry) and TGA (thermogravimetric analysis). The results showed that the greatest loss of mass of the tested materials occurred in the same temperture range (200-650°C), while the degradation temperature for PP, PV and refus is 362, 350, 348°C, respectively. The glass transition was similar (73,94; 70.07; 73.61), with changes in the enthalpy value (2.64; 2.19; 0.25). Thus, it is concluded that is possible to obtain the separation between fiber and matrix, allowing the reuse and recycling of othophtalic polyester reinforced with fiberglass.

Abstract:

Composite materials have been widely studied, mainly because they are widely used in products from several industrial sectors. Due to this wide use, research has been carried out with the objective of replacing the use of synthetic fibers with natural fibers, in these products. Therefore, this work aimed at the study of piassava fibers collected from a broom factory in Campos dos Goytacazes-RJ as industrial waste, in an epoxy matrix. Initially, the fibers were washed and dried in a stove and, subsequently, their morphology was analyzed with the aid of SEM. Finally, composite plates were produced and cut to dimensions recommended by the standard for performing static flexural tests. As a result, the flexural strength value of approximately 60MPa was obtained for 60% fiber reinforcement. Therefore, confirming the possibility of using a residue for the production of quality composite.

Abstract:

Currently, there are many environmental concerns. These range from the origin of the materials to their final disposal. In contrast, polymeric composite materials reinforced with synthetic fibers are increasingly seen for the production of products in various industrial sectors. Then, to reduce the impact of the use of fibers of artificial origin, research has been developed with the purpose of replacing them with natural lignocellulosic fibers. Therefore, this study aimed to analyze the tensile strength of polymeric composites formulated with epoxy resin and 30% to 60% piassava fiber. As a result, a resistance growth trend was obtained according to the increase in the amount of fiber. The highlight was the proportion of 40% that obtained, approximately, 29MPa.

Abstract:

High performance coatings (HPC) are floors that protect substrates in several types of Brazilian industries. Its use is necessary due to several benefits such as speed of application, high mechanical performance and absence of expansion joints. However, the Brazilian standard mentions manufacturing with epoxy resins, of synthetic origin, and mineral aggregates. Therefore, this work aimed to study the mechanical performance of this material using a vegetable polyurethane resin and, as an aggregate, piassava fiber ground in the knife mill. The fiber used was obtained as an industrial by-product of a broom factory located in Campos dos Goytacazes-RJ. The research methodology consisted, initially, in the determination of the density of the fibers collected as waste through the pycnometry technique, as well as the morphological analysis through scanning electron microscopy (SEM). Subsequently, water absorption tests were carried out after boiling, compressive strength and fracture analysis using SEM. The results showed the efficiency of using 20% fiber that makes it possible to apply this composition for formulation and use in RAD.

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One of the polymeric materials used in everyday life is polyurethane (PU). This polymer has a marked success history due to characteristics such as lightness, low cost and versatility. However, one of the disadvantages of using this material derived from a petrochemical source is the emission of volatile organic compounds, non-biodegradability and problems with disposal. For this reason, it is essential to develop green, economical, efficient and biodegradable materials for different applications. One way to create eco-friendly PU is to use vegetable oil as a polyurethane polyol. So, this work aimed to study the parameters of making two-component polyurethane matrix derived from castor oil for making High Performance Coating (HPC) to be applied on floors. For this, several proportions between components A and B were initially tested for compression. Then, the samples that stood out were observed by SEM. Finally, RAD cp's were formulated and tested again for compression using different post-cure temperatures. As a result, it was found that the best ratio of A: B to RAD is 1: 1.80 with curing at room temperature.

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The fibers extracted from the stem of the seven-islands-sedge (cyperus malaccensis lam.) plant have been investigated as possible composite reinforcement, aiming to discover a possible new fiber for an engineering aplication. Acording to , ASTM D2101, for the first time in the literature the diameters of the fibers were analyzed by the Weibull method, indicating an inverse depence and higher tensile strenght were achieved for the thinnest fibers. Besides an investigation of the microstructure by a scanning electron microscopy have shown a mechanism for this dependence. Also a mathematical hyperbolic relationship have been found to adjust the inverse correlation.

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Research on natural fibers as a possible engineering material is increasing, since it is possible to identify a series of benefits in NLFs such as: low abrasiveness, low price, low density and high especific tensile strength. These properties combined with their biodegradability raise interest in the research of NLFs. Therefore, in this work, for the first time in the literature, its presented results that were obtained relating the frequency distribution of the diameters, together with their density by diameter range of seven-island-sedge fibers. In addition to a mathematical correlation between the density and the inverse of the diameter a morphological characterization of the seven-islands-sedge (Cyperus malaccensis Lam.) through scanning electron microscopy (SEM) analysis were performed.

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A growing concern about the limitation of non-renewable resources has brought a focus on the development of environmentally sustainable and biodegradable composite materials. In this context, a trend in the development of natural fibers used as a reinforcement in composites is exponencially increasing. Therefore, in this work, for the first time in the literature, results of the seven-islands-sedge (Cyperus malaccensis Lam.) physically characterized by X-ray diffraction and the crystallinity index were by obtained diffractograms. Besides, an evaluation of the interface adhesion of the fiber and an epoxy resin was made by the critical length obtained in pullout test.

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The fibers extracted from the stem of the seven-islands-sedge (Cyperus malaccensis Lam.) plant have been investigated as possible composite reinforcement, aiming to review a possible new fiber for an engineering application. For this reason, these fibers were incorporated into epoxy matrix in different volumetric fraction of 10, 20 and 30 vol%. and were investigated for their mechanical properties associated with tensile strength. Plates were fabricated following the dimensions of 150 x 15 x 2 mm as required by the ASTM D3039 standard. The statistics analysis of the results was performed by ANOVA and Tukey tests based on a 95% confidence level. Besides, a Weibull analysis was applied and disclosed a great confidence degree for the Weibull parameters.

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Epoxy composites reinforced with 10,20 and 30% in vol. of a scientifically new natural lignocellulosic fiber in terms of its use as an engineering material known in Brazil as seven-islands-sedge (Cyperus malaccensis Lam.) were, investigated for mechanical properties associated with Izod impact test. Specimens with dimensions of 60.25 x 12.7 x 10 mm, as required by ASTM D256 standard and were fabricated in a steel mold by mixing aligned fibers with an epoxy resin hardened with triethylene tetramine. The results have shown that the composite with 30 vol% fiber presents more effective reinforcement. Statistical analyses of the impact energyss data obtained, were performed by Weibull method, ANOVA and Tukey test. Both the Anova and Tukey test analyses were based on a 95% confidence level. The Tukey test confirmed that the reinforcement of 30 vol% of seven-islands-sedge fibers in epoxy composites presents the highest absorption energy showing a significant difference for a pure epoxy matrix and a 10% of volume fraction reinforcing composites. The Weibull analyses exhibited a satisfactory linear adjustment confirming an homogeneity in the specimens group.

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FILTRATION IS A SOLID-LIQUID SEPARATION PROCESS WIDELY USED IN MINERAL PROCESSES OF IRON ORE. TO UNDERSTAND THE RELATIONSHIP OF THE 17 VARIABLES THAT INFLUENCE THIS PROCESS, TWO MULTIVARIATE STATISTICAL TECHNIQUES WERE USED. THE FIRST ONE, PRINCIPAL COMPONENT ANALYSIS, WAS CARRIED OUT. SIX PRINCIPAL COMPONENTS WERE IDENTIFIED, WHICH EXPLAINED 72.3% OF THE ORIGINAL DATA. FIVE OF THEM WERE GROUPED INTO CATEGORIES: PRODUCTIVE CAPACITY, CONTAMINANTS, OPERATING CONDITIONS, PRODUCT QUALITY AND EFFICIENCY OF THE FILTER. THESE GROUPS WERE ALSO CONFIRMED WHEN FACTOR ANALYSIS WAS APPLIED. USING BOTH TECHNIQUES, IT WAS POSSIBLE TO VERIFY STATISTICALLY THAT THE CURRENT VARIABLES OBSERVED IN THIS PROCESS ARE ADEQUATE TO MEET THE EXPECTED QUALITY AND PRODUCTIVITY PARAMETERS.

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Authentication is the means to make sure that the user or the remote object is actually who you are claiming to be. It is an essential security service because reliable authentication ensures access control, determines who is authorized to access information, allows audit trails and ensures the legitimacy of access.

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The current trend to replace shaped refractory with monolithic ones is due to many technical aspects, as lack of expansion joint, free shape, etc. Although, since liquid is added to the material for mixing and reaction of the binding agents, it is necessary to have a careful procedure during the first heating, so the generated vapor can be slowly released, instead of pressurizing inside the material. Because of this, conservative heating profiles are applied during this stage, yielding higher energy costs and maintenance time. Based in this context and considering the recent advances in numerical simulations, this work discusses the implications of the use of different heating rates during the drying of the monolithic lining of a steel ladle. Moreover, a novel parameter is introduced to correlate the maximum vapor pressure and the material’s mechanical resistance. The results point that higher values of pressure and a displacement of the position of this pressure peak are obtained in higher heating rates or larger lining thickness, moving the peak towards the hot face, where fracture is commonly observed. Although the results are preliminary, they show that this is a tool with high applicability to the industry and high technological value.

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Use of computers has growing so grandiose, because of this, the interest of the people to be more detail on this matter and seek information for their survival in the virtual environment has grown as well. Over time, these same people in which sought knowledge for their survival realize that to go further. Thereafter, try new experiences in virtual environments, making invasions in common users, or even of large companies. This work was done in order to create a culture of prevention to connect the Internet, guiding and preventing users from using computers safely and correctly. Demonstrating that the most common means of attack and how to avoid these types of attacks. It was established mechanisms, not to create a network 100% safe, but have ways of how to prevent and avoid these types of attacks.

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Based on a model proposed by [1] that simulates a beam in Hot Rolling Mill, whose LQG Controller maintains product dimensions within quality tolerances. A parallel plant was then created, which uses the output signal from the LQG Controller as a reference to another Neuro Adaptive Controller, which in turn controls the hydraulic actuator of the model of [1]. This Controller is an adaptive control with an approximation made by an RBF neural network, based on the work of [2]. To optimize the Adaptive Neuro Controller this paper proposes a gradient descent in the neural network, parameter update through iteration and a qualitative discussion about the Lyapunov Stability method.

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Simulations of blast-furnace loading using discrete element method provide information that aren’t often available or are difficult to measured in the industrial operation such as particle segregation, size distribution and charge porosity. Additionally, these simulations can be couple to models that help predicting breakage events suffered by granular raw materials. The present work deals with the application of a new modeling strategy of blast furnace loading based on discrete element method. Contact parameters for the raw materials used in the simulation have been characterized using bench scale experiments. In DEM simulations, the real scale of the operation was considered, from the hoppers to the top of the blast furnace. Simulations of the hopper loading, and its discharge were performed considering the movement of the rotating chute used in the industrial operation. The results allowed for the identification of the ideal loading condition of the coke and mettalic mixtures and will serve as basis for the development of a detailed phenomenological blast-furnace loading model.

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Refractory materials are widely used in the steel industry because, in addition of their resistance at high temperatures, they are developed to meet the demands associated to mechanical resistance. Thus, in order to ensure a good performance, some equipment must use an appropriate refractory material, in a feasible way. In hot strips rolling, the reheating furnaces use refractories of different compositions compatible with the use requirements. The doors of these furnaces require special attention because they are in a chemically aggressive environment, which has different kind of temperatures and stresses. Therefore, this methodology includes thermal and structural analysis carried out through computational modeling using Heat Flow and Ansys, related to the information of temperatures that the doors are subjected and other variables of the refracting system. It was possible to adapt the coating materials for the reheating furnace for hot strip lamination in a more economical and sustainable way using some information as density, internal furnace temperature, convection coefficient between the door and the internal part, and the emissivity of the structure.

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THE WORK PRESENTS THE RESULTS OF A GREENHOUSE GAS MITIGATION OPTION CARRIED OUT THROUGH A SIMULATION OF THE USE OF CARBONIZED BIOMASS AT DIFFERENT INJECTION LEVELS ON BLAST FURNACES OF COKE AND COAL, FOR A STEELMAKER ON THE INTEGRATED ROUTE. THE OBJECTIVE IS TO PRESENT THE USE OF BIOMASS AS ONE OF THE OPTIONS FOR GHG REDUCTION, A REGIONAL SOLUTION, TAKING ADVANTAGE OF THE COMPARATIVE CHARACTERISTICS OF THE LATIN AMERICAN CONTINENT. THEY WERE SIMULATED AS INJECTION RANGES OF 3%, 6% AND 10% OF CARBONIZED BIOMASS IN A BLAST FURNACE WITH INTEGRATED BF / BOF ROUTE, OBTAINING AN EXPECTATION OF EMISSION REDUCTION AND THE AMOUNT OF BIOMASS NEEDED TO SUPPLY THIS DEMAND.

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Concrete is the most produced and consumed material in the world and can admit in its composition the addition of various types of waste. Addition of tire splinter residues in partial replacement of the washed sand in the concrete mass contributes to a correct disposal of this residue that is often discarded in the environment. This study investigated the addition of tire rubber residues (splinters) from the resurfacing service in the city of Porto Nacional / TO. Concrete produced with an addition of 5% to 20% was investigated. The results show that the greater the addition of the residue, the greater the influence on mechanical and technological properties. The reduction of resistance is favored with the addition of rubber, which happens in an inverse way with density and workability.

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Slag making is vital for a stable BOF Process, in regular operation, it is intended to have a suitable final slag for lining maintenance. In many cases, the final slag is not in good condition, which demands slag correction. This paper proposes a slag correction model that connects the shopping floor background with theoretical knowledge and data science to describe the methodology used for slag correction at Ternium Brazil. The correction model considers the relationship between MgO saturation and liquid fraction as a critical parameter to promotes slag adherence on the converter walls. As a result, the model implementation provided economic savings by efficient materials consumption and an increase in the converter walls' cover efficiency

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The purpose of this document is to describe the new technology developed to increase safety, reduce the manpower needed in dangerous areas. New technologies now available, new reliable models of robots, the requests from the end users and the presence of new specialized supplier focused on the robotics business but with skills in the steel industry have create a new range of robotic solution able to increase safety, productivity and quality. The integration, made in different steps, both in automation and robotics side introduce the concept of the industry 4.0, the digitalization of the information shared with the existent automation and the efficient and friendly interface allow to increase the productivity and reduce the human presence out of the control pulpit..

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According to the newest trends, continuously cast products require full precise surface treatment or deburring at the front and/or tail ends before next process steps. Based on their experience and know-how with abrasive machining processes (abrasive cutting, high-pressure grinding) over a period of more than 50 years up to now, BRAUN has developed a highly flexible surface grinding and deburring grinding machines for applications which are too difficult for conventional deburring techniques. The subject paper describes the key features and advantages of BRAUN’s machine design and the operational results from the first already completed projects

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The demand for advanced high strength steels (AHSS) remains high in the automotive industry. Among the first generation AHSS Complex-Phase (CP) steels have been receiving attention as possible substitutes for Dual-Phase (DP) ones due to a higher yield strength and being less prone to void nucleation. An important and challenging aspect in the production of CP steels is the microstructural characterization. These steels can present in their microstructure ferrite, bainite, martensite, retained austenite and pearlite. The combination of characterization techniques such as light optical microscopy (LOM) with color etching and electron backscatter diffraction (EBSD) has been successfully used for microstructural quantification. However, EBSD techniques rely on complicated and long sample preparation processes as well as long collection times. A possible alternative to EBSD would be the use of atomic force microscopy (AFM). In this work, two recently produced CP class steels whose microstructure was quantified by LOM and EBSD were characterized by AFM. The quantification results show that the AFM can be used to complement the data obtained by the other techniques.

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At Usiminas it was observed that Blast Furnace #1 (BF#1) was presenting hot metal with higher silicon contents than Blast Furnace #3 (BF#3). In order to verify the operational correlations that justify this difference in quality, a statistical analysis of the blast furnaces operational data from January to April 2021 was performed. The t-test for independent samples and the Mann-Whitney were used for comparative evaluation between the furnaces. In addition, a factor analysis of the data was performed considering the dynamic complexity of the reactors. BF#1 presented operating parameters favorable to the reduction of silicon in hot metal when compared to BF#3, such as: lower coke rate, lower hot metal temperature, higher productivity, and higher level of oxygen enrichment. However, it presented a higher fuel rate and higher quartz loading when compared to BF#3, which may have favored the greater incorporation of silicon in the BF#1. For BF#3 the counter pressure system had a great influence to reduce the silicon of the hot metal, indicating that, due to technological differences, the furnaces must not operate in the same way regarding silicon control.

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Agglomeration of natural and anthropogenic iron-containing fine raw materials plays a very important role in ferrous metallurgy, allowing the recycling of significant volumes of sludge and dust, which otherwise could lead to a significant negative impact on the environment and to the ineffective use of large areas for their disposal. This study show different examples which demonstrate the possibility for efficient usage of organic binders in ferrous metallurgy agglomeration. The usage of BASF organic binders can be combined or complemented with inorganic binders such as sodium bentonite or other materials to increase thermal stability and to improve the behavior in the furnace. The low dosage of BASF organic binders required in the ferrous material and avoid dilution of desired metal into the furnace, which indicates there is an economic benefit to be obtained.

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The reduction of mining reagents is a priority for the mining industry with the advent of social and environmental concerns, and for technical factors. Cationic collectors, typically etheramines, are the major reagent used in the iron ore flotation process and are also the most costly. Their consumption tends to be higher as the quartz content of deposits increase. The high dosage can impact the iron recovery and increase foam issues in processing plants. Higher amine consumption negatively affects global sustainability, with more freight, more stockpiled volume, higher chemical production, and higher CO2 generation, as examples. Three etheramine collectors were evaluated in the flotation of two typically Brazilian iron ores (friable itabirite and semi-compact itabirite). Arosurf® MG70A30, Tomamine® M-4713 and Tomamine® M-3513 were tested to determine the technical and economic feasibility while meeting SiO2 specifications. The main references for evaluating the results were the standard amine dosage normally used in the industrial process of each ore. Arosurf® MG70A30 achieved higher iron recovery for friable itabirite with a reduction in the amine consumption by 25%. With the semi-compact itabirite, Tomamine® M-3513 provided higher iron recovery with at least 40% lower amine consumption.

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performance of the mineralogical analysis laboratory in Minas-Rio, by Anglo American. Monitoring of data through cash management, investment in training for capacity building, empowerment of the technical team and strengthening of the planning routine had a strong effect on the project indicator. The average quantity of tablets analyzed per week rose from 11.9 to 23.9 as soon as the project was completed and is at 21.8 after almost a year of completion. The annual amount saved with third party analysis is almost one million reais.

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Duplex stainless steels (DSS) are a type of stainless steels composed of approximately equal proportions of ferrite and austenite, α and ɤ, respectively. They are able to combine high mechanical resistance, ductility, corrosion resistance and weldability. Thus, they can be used in several industrial segments, such as the nuclear, civil construction and papermaking industries. Depending on the conditions to which it is submitted, the proportions of the phases formed can be altered and, consequently, their mechanical and electrical properties. Therefore, their production history and the conditions of thermomechanical treatments to which they were submitted, must be well known. Thus, the DSS 2205 cold rolled and annealed at different temperatures was characterized by optical microscopy (OM) and scanning electron microscopy (SEM), Vickers microhardness, as well as its electrochemical behavior, using the electrochemical impedance spectroscopy technique (EIS). The thermomechanical treatment to which the alloy is subjected affects the passive layer formed in the DSS 2205. For the annealed samples, the increase in the annealing temperature improved the properties of the passive film.

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The roughness is an important factor related to surface integrity and when referred to Steel Duplex UNS S31803, that have biphasic microstructure composed of grains of mechanical properties distinct, can show specific features during the turning process due to the elastic recovery of each grain. In this way, the variation of parameters in elapse of cutting process implies in surface finishes that, without a quality control, may generate a finish susceptible to stress concentrators with low useful life under fatigue. Therefore, the objective of this work is to analyze the roughness variation of Duplex Steel during the turning, seeking out to predict its behavior when submitted to variable cutting conditions. For this, were realized different measurements of roughness by means of a roughness meter/profilometer and subsequently statistical methods such as ANOVA and Taguchi were applied for the treatment of the datas. The variable parameters are the feed rate, the rotation, the nose radius and the cutting depth at two levels each. Forthwith, was proposed a mechanistic model to examine the behavior of roughness depart the variation of cutting parameters more influents.

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Molybdenum containing fire-resistant structural steels are available on the international market, but are much more expensive than conventional structural steels, inhibiting its use in the building industry in Brazil. Molybdenum promotes the formation of acicular microstructures, solid solution hardening, and delays secondary carbides coarsening. Mo containing fire-resistant steels are less susceptible to loss of mechanical properties when exposed to fire situations, showing yield strengths, at 600 °C, at least 2/3 of the room temperature yield strength. The development of lower-cost, new lean Mo fire-resistant steels, not requiring thermal protection, is a technological challenge in the steelmaking and building industries. This research project seeks the development of the combination of a new alloy design (reduced molybdenum contents) with controlled thermomechanical processing. Boron and Niobium additions to microalloyed steels may provide synergisms for the formation of acicular structures and enhance secondary precipitation of carbides, at a lower cost. The research aims the optimization of the relationship between microalloyed carbides precipitation in austenite, for grain refining, and secondary precipitation in the ferritic phase at fire temperatures, to increase yield strength by self-healing processes.

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The acquisition of asset data in an industrial plant is a challenge, the large number of variables linked to connectivity problems presented in the coverage of an extensive built area are crucial factors in the development of a data acquisition system. With the evolution of the Internet of Things theme, through protocols that make data available over a long distance, with low energy consumption, it is possible to cover large areas with reduced infrastructure. This work presents details of the implemented architecture, the protocol used, the territorial coverage obtained within the Ternium Brasil plant and the integration with the plant information management system (PIMS) present at Ternium Brasil.

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Prior knowledge of metallic and coke loading profile using moving plates is important for controlling the loading distribution within in blast furnaces. The present study evaluated, through computer simulation, the load distribution inside the Usiminas Blast Furnace 3 as a function of different positions of the moving plates. The computer simulation of the Blast Furnace 3 loading was performed using the Discrete Element Modeling technique, which allows the evaluation of the behavior of particulate materials. Using actual values obtained by measuring the dispersion of the loading in the blast furnace, it was possible to calibrate the friction of the particles involved and, consequently, the computational model was validated. With the validated model, the load distribution within the Blast Furnace 3 was determined as a function of different positions of the moving plates. The results of the simulation showed changes in the coke and metallic load distribution as a function of the position of the moving plates. Through the results found by the computer simulation, it was possible to identify new positions for the moving plates that allowed a better operational stability to the Blast Furnace 3

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Refractories, materials used industrial equipment, are associated with range of environmental problems. Refractory wastes are historically disposed of as waste in industrial landfills. However, some of the refractory materials used have the potential to be recycled, contributing to environmental and economic sustainability. The addition of recycled aggregates of system Al2O3-SiC on refractory concrete of the Al2O3-SiC-C system were evaluated for the development of refractory recycling technology after use. In general, the results of the dynamic slag test indicated the potential of the use of recycled aggregates of charging ladle, torpedo ladle car and slide gate plates.

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Presentation of biocide technology with equipment that generates chlorine dioxide without the formation of chlorides, which enabled an increase in the cycle in cooling towers, a reduction in the impact of changing the Quench of the process and a reduction in the corrosion rate of the company's assets. In addition to reducing sodium hypochlorite consumption and packaging handling - Reverse Logistics

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In order to obtain new materials, man began to combine different types of materials, thus creating composites. These can not only have properties and costs more attractive than conventional materials, but also generate environmental benefits such as minimizing the consumption of natural resources and taking advantage of waste that would once have been discarded. In this sense, this work aims to characterize the linear thermal expansion of composites reinforced with coconut shell particles in two configurations, processed and unprocessed. The processed particles were ground for 24 hours in a ball mill of the brand Servitech, model CT-240 / A. The tests were performed on a Netzsch dilatometer, model DIL 402 PC, at a rate of 2°C/min, aiming to characterize the behavior of 30 to 190°C. Through the tests it was possible to characterize the behavior of the composites, as well as to observe what the behavior of the composites varied according to the amount of load, in a non-proportional way, and type of load. It is also added that the processing of particulates favors the reduction of internal stresses, influencing less than unprocessed particles in the expansion of the epoxy.

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Polymeric films containing calcium phosphates, graphene oxide, sodium alginate and collagen were produced using the casting technique for potential application in biomaterials. Films were characterized by XRD, SEM, Raman spectroscopy and swelling tests to assess their behavior in a physiological environment. In the microscopy obtained by SEM, it was possible to notice that the technique used was successful in producing homogeneous films. The X-ray diffraction results showed the presence of alginate, graphene oxide and the two phases of calcium phosphate (HAP e β-TCP), as well as in the Raman analysis, where the D and G bands related to graphene are identified. The addition of graphene oxide in the films was able to reduce the presence of fissures and increase the degree of swelling and, consequently, the resistance of the films to degradation.

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Companhia Siderúrgica do Pecem, after two years of operation, faced the great challenge of supplying Ultra Low Carbon steel slabs to be rolled in the European market. The level of quality would require a higher level of technological capacity of the company to serve this market. For this, cleaneless measurement techniques were developed and validated and the fundamentals of metallurgical phenomena and operational procedures that impact the cleaneless of Ultra Low Carbon steels with exposed and unexposed automotive application were studied in order to obtain a reduced exfoliation index in the product. The challenges consisted of defining refining and casting process parameters that would guarantee optimal levels of cleaneless based on the exfoliation results in the final product; and to develop cleaneless measurement methods that would allow for the continuous development of CSP refining processes. The result of this development positioned CSP as a reference in quality, with cleaneless levels 50% better than the best rolling company supplier until then, and levels equivalent to the slabs of the rolling mill company itself, which is one of the world references in this product line. The conceptual objectives stand out, such as the development of cleaneless assessment techniques that will allow CSP, a slab producer, to anticipate and act on steel projects in order to optimize quality according to the customer's needs; from the definition of correlations between exfoliation, total oxygen and the level of inclusions obtained in product; in addition to process mapping and knowledge creation for the organization.

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Integrated iron and steelmaking production represents the globally predominant technology. Global requirements for CO2 reduction will have impact on needed changes in iron and steelmaking philosophy using new technologies which generate less CO2. Based on forecast, hydrogen application in primary steelmaking and scrap melting process will have higher shares in part of World where integrated iron and steelmaking process is considered as traditional. Transition from traditional and well-established process to the process based on DRI / HBI production together with scrap melting in electric arc furnace must be followed by capability to produce high quality grades from content of residuals elements point of view. Required transition from integrated to electrical steelmaking philosophy could have impact on existing secondary metallurgy process as well. This article presents way how to keep capability to produce high quality grades with low content of residual elements using different charged material and using different secondary metallurgy configuration.

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In the steelmaking industry, equipment failures are highly concerning because of the extremely high temperatures and mechanical loads involved. The support rolls conduct the solidified slab through the continuous casting process, and thus are subjected to high mechanical loads. Sometimes, these repetitive loads produce discontinuities and failure, especially when there are areas more susceptible to cracks, such as the heat affected zone (HAZ) of the welds. In the present work, the failure of a continuous casting roll was investigated, and a new welding procedure specification (WPS) for repairing crack indications was proposed. Satisfactory results were obtained by using the ER70S-6 as filler metal and by controlling the pre and post-heating.

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Metal drums are useful and adaptable medium-sized cylindrical containers, which can be used both for transporting liquids and semi-solids. Its circular shape provides maximum strength, allowing it to be tipped over and rolled even when fully loaded. Among the efforts aimed at sustainable measures are those aimed at geometric improvements for an optimized use of metallic sheets that are the input material in the manufacture of steel drums, with these generally manufactured from cold-rolled steel sheets with thickness ranging from 0.292 mm to 2.4 mm. Therefore, the present work aimed to analyze the effects of reducing the thickness of the metallic sheet used in the manufacture of 200L steel drums on the axial compression resistance resulting from stacking. For this, the finite element method was used to simulate the loading conditions for drums made from metallic sheets with thicknesses of 0.85 mm (original), 0.75 mm and 0.65 mm. The results obtained demonstrate that the maximum stress values undergo large variations when a thickness reduction is applied, keeping the same materials and the same boundary conditions, with the upper seaming region for thicknesses of 0.75 mm and 0.65 mm requiring special caution.

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During slag granulation in a Blast Furnace Main Trough, the contact between water and slag can lead to explosions, due to presence of pig iron in the slag. Aiming to reduce the molten metal passage through the slag port in a Gerdau Ouro Branco main trough, numerical simulations were performed for different geometric configurations of the main trough. In the first part, the impact of increasing the width and increasing the depth of the main trough were analyzed. In the second part, it was analyzed the impact of increasing the slag thickness through the increase of main trough’s ΔH. Simulation results show that the width increase is efficient to reduce metal passage through the slag port, while slag thickening impacts positively in the fluid separation, but for the separation of metal particles, the positive impact occurs only above a certain increase in thickness.

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For integrated steel mills, sinter is one of the main raw materials that make up the metallic charge for the production of hot metal and can reach a majority in the charge. In view of this high percentage of sinter use, it is necessary that the raw material supply routes are adequate to the demands, obeying the requests and environmental requirements. Due to the complexity of the raw material handling process, a dynamic process simulation model was developed using a computer simulation software with multiple interactions. This model aimed to formulate, test and evaluate the raw material handling operations, identifying opportunities for systems improvements. The model was designed so that the input data were included using the software Excel, making it flexible in terms of filling in the information. The simulation developed proved to be very close to reality and was essential for the construction of the scope of several projects at USIMINAS – Ipatinga Plant. In addition, functionalities and possibilities were identified using the simulation model for application in the operation and maintenance routines.

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The high volume of tailings from mining has generated pressure on mining companies to seek solutions that minimize the resulting impacts and reduce the risk of accidents and disasters with tailings dams. This work aims to validate the centrifugal decanter equipment as an alternative to existing process routes such as filtration for disposal in drained stacking. Pilot scale tests were carried out with the slimes generated in the ITM-Samambaia plant of Mineração Usiminas, through the centrifugation process. The centrifuge process is based on the use of centrifugal force that increases many times the force that acts on the center of gravity of the particles, facilitating the separation and contributing to the reduction of the residence time in the equipment, this characteristic makes the centrifuges become the most efficient mechanical equipment in the separation of solids/liquids. The tests were divided into two stages, the first exploratory and the second used the Factorial Planning method with replica, with the sequence of tests and the respective rotation back drive (conveyor screw), feed flow and residence time (controlled by the water outlet opening) generated in Minitab® statistical software

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The objective was to approve a silica content analyzer by image analysis for advanced control and optimization of the CSN Mineração column flotation process. The methodology consisted of parameterization and construction of the equipment's algorithm, comparison tests with chemical laboratory and industrial tests. The qualitative results were greater predictability and stability of the process, faster flotation interference and greater chance of reaching the client silica content. The quantitative results are summarized in a good correlation with the chemical laboratory results, r² = 86% of the linear regression analysis. The variability of flotation concentrate silica content was reduce in 22% and the dosage of the amine reagent was reduce 10%. The number of the laboratory routine chemical analysis has a potential gain to reduce 50%. As a conclusion, the equipment showed significant gains in reagent consumption and stability of the CSN Mineração column flotation process.

Abstract:

Stainless austenitic steels are widely applied in the field of classic mechanical engineering. An important representative of these grades is the material 1.4404 (316L), which is well established as a standard steel in Additive Manufacturing (AM). Typical stainless austenites contain some main alloying elements, which are described in the following: The formation of an austenitic microstructure is achieved by nickel (Ni). The addition of chromium (Cr) lead to the corrosion resistance of these materials. For resistance to localized corrosion, molybdenum (Mo) can be added. However, this requires full dissolution of Cr and Mo in the steel matrix. As a consequence, stainless austenites usually exhibit very low carbon and nitrogen contents to prevent chromium carbides and nitrides. But, both alloying elements cannot be classified as being detrimental in stainless austenites in general. In contrast, C and N can also be used to improve mechanical and chemical properties. Based on this knowledge, a high-strength austenite was developed particularly tailored for AM. The mechanical properties of the new development, determined by tensile tests, show twice as high characteristic values (yield strength, Rp0.2, and ultimate tensile strength, Rm) compared to 316L, with simultaneously increased corrosion resistance against chloride ions.

Abstract:

The aim of this paper is to study the friction in the second shear zone by measuring the cutting forces during the turning process of the UNS S 32760. The variable parameters were the feed of the tool and the cutting speed. The depth of cut was kept constant and during this process no cutting fluid was used. Then, it was applied the results of the experimental cutting force in a numerical method presents in the literature in order to simulate the orthogonal cutting process using as basis the friction coefficient obtained in the experimental phase, the tool-chip contact length and other machining conditions, in order to determine the cutting forces. With the chip thickness measured on the scanning electron microscopy (SEM), the tool-chip contact length was calculated using some analytical models from the literature. After the analysis, the best model was chosen. After, numerical model results were generated to the determine the behavior of the cutting forces and stress in the tool-chip contact.

Abstract:

Advanced high-strength steels (AHSS) are now widely used in the automotive industry for body-car lightweight solutions to meet the environmental requirements of reducing CO2 emissions. Hot stamping boron steels with Zn-Fe galvanized coatings are an alternative to the issues arising from the reduced formability of other AHSS grades. The blank is first austenitized and subsequently stamped and tempered simultaneously in this process. This work aims to investigate the corrosion resistance of a hot-dip galvanized Zn-Fe boron steel sheet before and after hot stamping conditions. Open circuit potential testing in 4 wt.% HCl solution allowed to evaluate the dissolution of different phases present in the Zn-Fe coating. Electrochemical impedance spectroscopy tests in 0.1 mol/L NaCl solution permitted to assess the corrosion resistance of different coated samples. The EIS results showed that the stamping process decreases corrosion resistance and that the coating with higher Zn content showed superior corrosion resistance before and after hot stamping.

Abstract:

Black-box models have shown incredible felxibility and accuracy in prediciting what values certain variables involved in industrial processes will assume in the future, given the values of certain other variables. These models, however, are frequently too complex to be interpreted by a human operator, and are frequently unable to furnish adequate answers to queries regarding interventions in a given system, or to answer counterfactual queries. Causal models, however, frequently can. In this work we explore the causal modeling of two stages in the production of seamless steel tubes, extracting directed acyclic graphs, which can then be used for rule extraction, as well as for predictive, intervention and counterfactual queries.

Abstract:

The optimization of eletric energy consumption in an Integrated Steel Mill is important for reducing costs and increasing the company. The current scenario of economic crisis and high industry competition requires actions in several processes with a focus on reducing costs and increasing productivity. This project is developed at the Pecém Steel Mill in the Molten Steel. The development of this work consists of the collection, analysis and treatment of data on the electric energy consumption of the Molten Steel. Therefore, it is possible to obtain consumption diagnostics and identify reduction opportunities, which are dealt with in action plans that include technical and process improvements, automation, review of procedures and training of employees. The results obtained in the project consist in the reduction of the electric energy consumption of the Molten Steel, which contributes to a cost reduction and reduction of the distribution of electric energy from the thermoelectric, thus, increasing the possibility of selling electric energy to the National Interconnected System.

Abstract:

The work presents the development of a mathematical model for the loading of blast furnaces called SCAF which is able to predict the burden degradation during loading. In this model, simulations of the granular flow using the discrete element method (DEM) serve as bases for the calibration and validation of particle motion equations and provide the collision energies transferred to particles during blast furnace loading. The SCAF results show good correlation with those obtained from DEM simulations such as particle size distribution, ore/coke ration, blast furnace bed profile and composition, demanding low computation cost. With such a tool, the operators can then evaluate the outcomes of a loading strategy in real time, allowing for the Search for optimal operation conditions.

Abstract:

Brazil is considered a developing country, in the last decades it has presented remarkable progress in several aspects of the economy, education, politics, science and health. Recent advances in tissue engineering have focused on the use of biochemical and physic-chemical signals to trigger specific cellular responses and encourage better biological interaction between biomaterial and living tissue. As a result, there was a significant interest in the development of intelligent biomaterials, which can generate electrical stimuli in situ, for accelerated bone repair, healing, and regeneration. Piezoelectric ceramics may be the key to the functionalization of current grafts, as they exhibit mechanically generated electrical behaviour. In this work, the production of sodium and potassium niobate (KNN) will be adopted by the sol-gel method to observe changes in the microstructure. The synthesis was efficient, and the material has characteristics that validate its possible biomedical application.

Abstract:

The purpose of this work was to characterize a nanocomposite of CoFe2O4/rGO nanocomposite produced in a single step by the hydrothermal method. The characterization was performed by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR). From the results, it was possible to identify the phases, observe the morphology, determine the average size of the nanoparticles, and identify the functional groups present in the sample.

Abstract:

The Natural lignocellulosic fibers (NLFs) are widely studied due to factors such as the short period of growth, renewability and greater availability. In this perspective, this work aims to study the geometric aspects, such as diameter and length, and their relationship with the geometric and apparent density of the lignocellulosic fiber of caranã (Mauritiella armata). One hundred fibers were randomly selected for statistical analysis of length, mass and diameter, and later the apparent density was calculated in relation to distilled water, according to a DNER-ME 084/95 standard. The results showed a tendency to increase the geometric density for fibers that had a larger diameter, nevertheless, considered low when compared to other natural fibers and the bulk density was found below 1g/cm³, however, even with the values reduced from this property, the results are close to those compared with the researched literatures.

Abstract:

Danieli entered the converter business in 2011 with the inception of the new, dedicated business unit Danieli Linz. Activities ramped up rapidly in this highly demanding and conservative area of steelmaking. Currently, five BOF converter vessels supplied by Danieli Linz are operating worldwide with sizes between 80 t and 350 t. Another 300 t converter is currently under fabrication. Since July 2018 the converter technology has been fully integrated into Danieli Corus. Danieli Corus is already very successful in blast furnace iron making as well as niche markets for oxygen steelmaking. Danieli Corus is market leader in the supply of sublance systems together with one of the most advanced level 2 systems. With this new set–up of integrating the experts of Danieli Linz into the Danieli Corus group a great opportunity has been launched for further developing equipment in oxygen steelmaking. But on top of that, this is the first time that engineers of an equipment supplier of two disciplines (iron making and steelmaking) are working together in a single location. This opens completely new opportunities for the joint development of tools and software for optimizing blast furnace and converter processes in terms of cost and resource savings. In the area of converter off–gas capture, cooling and cleaning, current development focuses on maximizing the hood design’s coverage at minimum maintenance requirement. In the near future this item will be covered in more detail. Completed redevelopment of the scrubber and mist eliminator designs are discussed in this article.

Abstract:

Acindar a steel company with two 110 t Electric Arc Furnace (EAF) focused on to increase efficiency and cost reduction of the steelmaking process, planned to revamp the chemical energy package changing the equipment of oxygen and carbon injection on the two EAFs with the goal of decrease the consumption of injected carbon, oxygen and better slag foaming. The two EAF use to charge scrap and DRI continuously feeding with three ports of burner/oxygen and carbon injection. This project consisted in replacing the existing three ports of burner/oxygen and carbon injection for a new EAF chemical package, composed by copper blocks, burners and injectors of oxygen and carbon. Searching for the best technology currently available in the market, they chose the chemical package developed by Lumar to EAF, composed by Protect Block, FlexOx and Power Carbon (to the needy carburization points). In this paper will be presenting the chemical package equipments implemented in these EAF’s revamp, as well the installation project, besides the operational results obtained during startup. The main results were the reduction of the consumption of the carbon, oxygen, improvement of the formation of foaming slag and reduction of energy consumption of the furnaces.

Abstract:

The continuous slab casting process needs to comply with potentially incompatible demands: high productivity, lower costs, complex phase transformations during steel solidification and cooling, and semi-products with no defects. It is not always possible to match all these requirements intuitively, as the interactions between the various phenomena that occur during this process can be complicated and, eventually, contradictory. This was the motivation for the development of MacroSim, a digital tool based on Microsoft Excel, that analyzes operational data from the continuous casting machine and performs a process diagnosis from the point of view of slab quality and productivity. Among the analyzed parameters are the chemical composition of the steel, strand dimensions, casting speed, superheat, mold oscillation conditions, mold flux composition, secondary cooling water flow, among others. The variables that must be considered are simple and in a number that will not overburden the operational staff who must provide them. Some examples of MacroSim successful applications are described, where this tool identified the problems of the continuous casting process that were causing quality issues in the slabs.

Abstract:

The quality and performance of the GA coating is determined by its microstructure. The Fe-Zn phases that make up this coating have very distinct crystalline structures and physical properties. So, small changes in the system produce significant effects, ranging from malformation of the coating to its detachment. Therefore, the quantification of Fe-Zn phases is extremely important. In this work, the quantification of the phases present in a GA coating was carried out using X-ray diffraction data, from a TOPAS software. The results showed the robustness of the proposed method, obtaining satisfactory values of statistical indicators of refinement, as well as concentration of the phases in agreement with theoretical values expected for the coating. Hence, the application of this method will allow greater precision in the microstructural analysis of the GA layer, contributing to enhance the quality and performance of the coating through: optimization of the industrial processing cycles in hot dip galvanizing lines; improvements in the characterization and quantification of the Fe-Zn phases; and adjustments of the processing simulations on a laboratory scale.

Abstract:

The operatinal conditions of a blast furnace can affect the performance of the casthouse, leading to worsen efficiency and productivity. One factor linked to a good casthouse performance is the maintenance of the taphole length, generated by the taphole clay injection. The present work uses artificial intelligence techniques, Machine Learning, to develop an intelligent pattern of taphole clay injection. Specialists from ArcelorMittal Tubarão and Saint Gobbain used the supervised learning models, random forest regression type, to treat 46 operational parameters of Blast Furnace 1 in ArcelorMittal Tubarão, period between 2016 and 2019. An algorithm was generated to predict the subsequent taphole length with an accuracy of 57%. This model was validated in a new data set from the year 2020, proving its ability to predict the growth or wear behavior of taphole lenght. The new injection pattern was then subjected to the practical tests at tapholes 1 and 2 of AMT´s blast furnace 1. It is worth mentioning that the physical integrity of the tapholes was kept practically constant before and during the tests, beeing the wear index the main factor analyzed

Abstract:

In order to reduce the variability of the CaO content of the sinter, a comparative study of the deviations of the CaO content of the limestone piles was carried out using the Shell Cone stacking methods and the Chevron method. The piles formed were approximated in mass and two series of sampling were performed on the CFW scale belt of the limestone dosage in the Sinter. The first sampling series was with using the Shell Cone method and the second series with using the Chevron method. Each series was composed of 40 samples with the interval of 4 minutes. The results obtained showed that the standard deviation of the sampling using the chevron method was lower, bringing significant results for the stability of the sintering process. Keywords: Chevron stacking; Reduction of CaO variability.

Abstract:

Thickeners are equipment present in different areas of industrial processes in which solid-liquid separation is necessary. As an active principle of operation, the sedimentation process is used to separate the materials involved. This article involves optimizing the operation of a real, large separator used in the Brazilian mining industry. The study aims to reduce the amount of foam generated in the solid liquid separation, as well as the possibility of operational improvements. Based on the digital prototyping strategy, using a computational fluid dynamics (CFD) methodology, a discrete model of the equipment was created for forecasting, changing geometry and analyzing results. Commercial software Ansys CFX was used and the prototypes had significant improvements

Abstract:

The present work aimed to analyze the performance of a Non-Nuclear Density Meter installed after the thickening in the process step that precedes the filtration of the fine concentrate. The instrument installation point is strategic because it will be responsible for the adequate density measurement, resulting in the calculation of the Solids Percentage that will compose the cake generated by the Filter Press. The digital signal emitted by the equipment is essential for automation and, therefore, to the operational autonomy of the filter press.

Abstract:

This work aimed to investigate the effect of the laser scan speed, overlapping, size of the sample and substrate temperature on the density, microstructure and hardness of the recycled quasicrystalline former alloy, rich in aluminium, of the Al95Fe2Cr2Ti1 composition, when processed by selective laser melting (SLM) technique. The relative density of the samples was measured by Archimedes principle and longitudinal sections were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Vickers microhardness (HV). The relative density of the samples was not significantly changed with the tested process parameters. Higher laser speed resulted in a higher quasicrystalline phase fraction and also on a finer scale. The overlapping had more influence in the morphology of the melt pool for lower laser scan speed. The sample produced in large size and using substrate not heated presented superficial cracks visible to naked eyes. The heating of the substrate reduced the presence of the cracks at the sample’s surface. The sample built using higher laser speed resulted in higher microhardness and the bottom of the samples presented the highest hardness compared to the middle and top regions.

Abstract:

This work applies Molecular Dynamics (MD) simulations for a better understanding of the particle bonding mechanism at an atomic level on Cold Spray processes (CS) in ferrous substrates. The particle potential energy variation analysis revealed that bonding mechanism in CS process can be associated to mainly two energy components: cohesive energy and adhesive energy. Depending on the process parameters (especially feedstock material choice), deposited particles could achieve a more stable condition than free particles. This might be an indicative of better adhesion between the particle and the substrate. For the simulation conditions, the study finds that aluminum particles are better suited to achieve more stability on ferrous substrates. Regarding the impact velocity, values around 1000 m/s (for copper particles) leads to more stability in ferrous substrate. Smaller particles of copper also achieved more stability on ferrous substrate.

Abstract:

A comparative evaluation of two High Strength Low Alloy steels, regarding their ability for the quenching and partitioning (T&P) process, was performed. To carry out the study, the ThermoCalc program was used with a database in the TCFE9 version, which served as the basis for: determination of the composition of austenite in the intercritical field; determination of the equilibrium temperatures of phases that delimit the intercritical field (Ae1 and Ae3), and obtaining the precipitation maps of the referred alloys. With the aid of empirical equations, the onset temperatures of the bainitic and martensitic transformations (Bi and Mi) were determined, which were used as a basis for the performance of the one-stage quenching and partitioning heat treatments. The quenching heat treatments were carried out on a pilot scale in a muffle furnace with temperature monitoring and oil cooling. The ImageJ software was used for quantitative analysis of the alloys in order to have an estimate of the percentage of retained austenite present in the alloys (estimated as a function of the % of MA constituent). As a conclusion of the work, it was observed that alloy a, with additions of Mo-Ti-Nb-B (MA > 9%) compared to alloy b with additions of Cr-Mo-Nb-B (%MA < 8%) presented the higher values of total elongation indicating that this alloy has greater suitability for the T&P process.

Abstract:

A level 2 automation mathematic model simulator was developed for a cold tandem mill (TCM) at Usiminas in Ipatinga. This simulator is important to predict line equipments setup behavior, increasing the reliability for handle tests with new materials and improving process and products quality due to greater operational predictability. The system's philosophy was based on the domain-driven design methodology [1], focusing on creating a framework that can be used for the simulators development with metallurgical team support. Using the created framework, the specific simulator for the laminator was developed. The final system obtained is accessible from the internet browser of any computer on Usiminas internal network and has been validated by the technical experts of the process

Abstract:

Abstract:

The German company Kuttner TDCo has developed a bell-less system for Blast Furnaces. In total four of these systems have been installed at the blast furnaces at voestalpine/Austria between 2009 and 2014. After five years of operation the systems have proven their advantages in operational performance, durability and maintenance friendliness. The experiences gained during this operation period allowed voestalpine and Kuttner TDCo to implement further improvements at the design of equipment. These improvements have been implemented during repair and maintenance activities of the chutes in the Kuttner TDCo workshop in Germany.

Abstract:

In 2019, during an operation of oven nº43 at coke plant nº3 at Usiminas Ipatinga, the hearth bricks were damaged. This fact interrupted the operation of this oven until the definition and implementation of the repair methodology. The early identification of problems and appropriate methodologies for repairs are constant challenges throughout the life of coke batteries. Thus, this article describes the general aspects of the equipment, the situation the oven, the repair methodology adopted for this problem and the results achieved. The developed methodology allowed the recovery of the refractory lining of the hearth using electrofused silica refractory bricks with the aid of ceramic welding. Since the implementation of this technique, it has been possible to minimize the risk of damage to the threshold. This benefit reflected in greater availability and operational safety of the coke oven at the Ipatinga industrial plant.

Abstract:

Steel industry is one of the most important sectors for country's economy, its production supplies many consumer goods plants, in addition to being fundamental for infrastructure works. The tendency for steel production is increase, as well as consumption, and it cannot be different because many countries there is much to be done and steel will be fundamental. All this progress has been accompanied by the emission of a large amount of greenhouse gases into the atmosphere, mainly by burning fossil fuels. The sector is responsible for about 7% of all CO2 emitted in the world, 69% comes from burning coal and coke in blast furnace. This is not a recent problem, since the world energy matrix is based on burning fossil fuels and the steel production route that was consolidated, due to the high productivity, was the blast furnace (72% of the production). Several agreements and meetings have been held around the world with the aim of mitigating and reducing CO2 emissions. European countries are one-step ahead, as their agreements are better established and goals are well defined, so that, most of works and researches in the area of steel production with reduced emissions comes from there. Researches shows that the main alternatives for low emission steel production are: use of biomass replacing fossil fuels (total or partial); steel production using scrap, via electric arc furnace; use of hydrogen to reduce iron ore (in PCI and DRI). Therefore, this work aims to show these three alternatives studied and applied in steel production in order to reduce greenhouse gas emissions. In addition, it intends to stimulate discussions about the future of steel production with emission restrictions, seeking mainly short and medium term solutions that maintain the competitiveness of steel mills.

Abstract:

Concrete is the most produced material in the world and can admit in its composition the addition of various types of waste. Addition of disposable glass in partial replacement of the washed sand in the concrete mass contributes to correct glass disposal. This study investigated the addition of residual glass to the concrete with percentages of 5% to 20%. The results show that the greater the addition of glass, the greater the influence on mechanical and technological properties. Additions 15% and 20% resulted in a strong loss of resistance to uniaxial compression, more favoring workability.

Abstract:

The importance of surface treatments of natural lignocellulosic fibers (NLF) in the properties of composites is recognized, whether they aim to prepare the fiber to withstand the chemical environment of the matrix or to improve the characteristics of the fiber-matrix interface. Recently, some authors have reported good results in the coating of FNL by a lignin derivative, lignosulphonate (LS), which is a by-product from cellulose production. The research of LS as a modifying agent of FNL is still incipient, but it has shown promising results for composites. Therefore, the objective of the present work is to study the surface modification of piassava fibers when subjected to treatment with LS and sonication. The fibers were characterized by X-ray diffraction, Fourier transform infrared spectroscopy (FTIR) and tensile tests. The results showed that LS is absorbed by the fiber and an increase in the average tensile strength occurs. On the other hand, no variation in fiber diameter and crystallinity was observed.

Abstract:

BRAZIL IS THE LARGEST PRODUCER OF CRUDE STEEL IN THE AMERICAS BY BOF PROCESS AND MANY CHALLENGES COME ALONG WITH THE INCREASING MARKET DEMAND. THE INSTALLATION OF CO-EXTRUDED COMPOSITE TUBES BROUGHT UP NEW AND POSITIVE PERSPECTIVE FOR THE BOF HOODS IN STEEL REFINING. IN ORDER TO RISES SAFETY AND PRODUCTIVITY, IT COULD BE OBSERVED AFTER VISUAL, ULTRASONIC AND LP TESTS THAT FUTURE PERFORMANCE OF ARCELORMITTAL-CST’S HOOD MAY POTENTIALLY BE EXTENDED DUE TO TUBE LOWER WALL THICKNESS LOSS AND ABSENCE OF CRACKS. BOTH REGIONS WHERE TUBES WERE INSTALLED REVEALED THAT THE MATERIAL SELECTION (ALLOY 690) AND ITS TUBE TECHNOLOGY CHARACTERISTICS VERSUS OVERLAY WELDED TUBE OVERCAME THE EXPECTATIONS AFTER 6 MONTHS UNDER OPERATION.

Abstract:

Bottom skull formation is a common problem in electrical arc furnace for high alloy steel production, especially when a high percentage of FeCr is charged into the furnace together with short tap-to-tap time. Skull formation creates a number of process problems such as reduced furnace volume capacity, lower tapping weight hit ratio, lower steel yield. The formation mechanism of bottom skull in a 70-ton EBT furnace for tool and stainless steel production in SeAH’s steel plant in Changwon, Korea has been investigated. The effect of bottom gas stirring and electromagnetic stirring (EMS) on skull thickness reduction has been compared. The results show that EMS is a more efficient way to reduce skull formation in the furnace compared to gas stirring. The steel temperature in the bath is more homogeneous and target tapping temperature is controlled more accurately, which smooths downstream VOD operations. Short tap-to-tap time and consistent furnace operation also give increased productivity. The effect of EMS on electric energy and electrode consumption has also been discussed.

Abstract:

Abstract:

At Companhia Siderúrgica do Pecém (CSP), in mid-2021, the mark of implementation of the new refractory profile on the sole of continuous casting tundish was reached by more than 90%, called "raised bottom" with reference to YES® technology (Yield Enhancement System), which aims to reduce the amount of the remaining steel in tundish (tundish skull) at the end of the continuous casting process, equivalently replacing the remaining steel volume with refractory material, thus keeping the height of the final column of liquid steel over the strands unchanged, or that is, optimizing the final residual steel in the tundish while maintaining the same operational safety condition and process quality. In view of the implemented improvements, the need arises to revised the casting speed reduction curves for the emptying of steel in the tundish and closing or not of the strands, given of the sequence end or tundish exchange, in order to readjust the process to the development of the refractory profile of "raised bottom" to meet the new goal of the amout of remaining steel in the distributor (tundish skull) established in view of the proposed improvement.

Abstract:

The growing demand for costs reduction in steel packaging applications requires the development of high strength packaging steels to meet these requirements, as well as computational resources that allow estimating the performance of a given product before sending it to the production line. The present study aims to analyze the effects of thickness reduction in packages produced from DR550 metal foil, in order to obtain comparative data for the construction of a computational model. For this purpose, samples of packages produced with thicknesses of 0.14 mm and 0.15 mm were submitted to axial compression tests. The computational model was obtained using the finite element method together with the results obtained in the experimental tests. Furthermore, using the constructed model, the axial compression test was simulated for packages produced from metal sheets with a thickness of 0.13 mm. The results obtained by finite elements were satisfactory, since the values were very close to those found in the experimental tests, including the area where most of the strain was concentrated. The achieved finite element model can be used to predict the future behavior of the application of a given specification or to predict the results of a possible thickness reduction proposal.

Abstract:

Plant managers at blast furnaces are faced with the need of continuous increasing costs for safety, missing process predictability and missing process control causing production waist. This also involves the tapping and torpedo car loading process. Based on intense exchange with their customers TMT Tapping Measuring Technology, developed a torpedo car management system, allowing the end user to generate perfect process control on safety, time, predictability and documentation closing the digital gap between blast furnace and steel plant. Benefit is reported having an “assets profile” with strategic information about when the torpedo has been used the last time, how often and what is its condition. The software has the option to add functionalities at a later stage, depending on individual requirements. This is giving the manager a good tool for future use or the necessary information for planning maintenance. Based on this fact, a return on CAPEX investment is significantly attractive.

Abstract:

The standard test of iron ores’ reducibility in the blast furnace (ISO 7215) considers only CO as a reductant. Nevertheless, all BFs have different ranges of hydrogen in the reducing gases, which vary according to the auxiliary fuels used. A non-standard test, including hydrogen in the reducing gases, was designed aiming to develop a simple test that considers the real conditions to which the raw material is exposed as a fundamental step in laboratory characterization to reduce the gap between Lab results and industrial data. The present paper shows results of different pellets and lump ore tests along with some industrial data obtained from Ternium Argentina BF2.

Abstract:

Zinc is an indispensable metal in today's society. Nexa Resources is the only producer of this metal in the country. In the Vazante Unit, the ore expaded via underground mine is willemita. Flotation is the most used method for the processing of this mineral, being commonly used pre-sulfide with sodium sulfide followed by flotation with cationic collector. As there is no production of sodium sulfide in Brazil, there are higher costs with imports, in addition to the dependence of the market for not having a substitute. This article aimed to study the substitution of sodium sulfide through bench flotation tests. The reagents tested were the combination of sulfidrates with sodium hydroxide. The technological characterization concluded that the sample had 11.0% zinc content and had the typical mineralogical characteristics of Vazante (willemitic ore and dolomitic gangue). The flotation results showed that Sulfidrate 01 had similar performance to sodium sulfide, showing potential in substitution. Sulfidrate 02 and 03 were less selective than the sodium sulfide test, possibly due to the higher mass recover. It is concluded that sulfidrate can technically replace sodium sulfide.

Abstract:

Iron ore is a prominent input in the Brazilian economy, with Minas Gerais having a relevant position in this scenario. This is justified by the geological structure of the Quadrilátero Ferrífero. Understanding the technological properties of minerals present in iron granules is of paramount importance. For this, one can make use of statistical techniques that facilitate the understanding of industrial processes. Currently, statistical techniques have a central role in the various fields of scientific research, in particular, multivariate techniques have been widely applied in various scientific investigations in the areas of mineral processing. Thus, this work aims to compare the technique of multivariate analysis of main components by specific software with bivariate analyzes using electronic spreadsheets. In this work it was possible to observe that the multivariate technique proved to be more efficient and effective, allowing a broader analysis with new interpretations for the analyzed data.

Abstract:

THE HADFIELD STEEL EXHIBITS HIGH ENROWING CAPACITY WHEN SUBMITTED TO EFFORTS. CONSTITUENT ELEMENT CONTENT MAY EXERCISE A RELEVANT ROLE UNDER THIS PHENOMENON. FOUR HADFIELD STEELS WITH DIFFERENT CARBON CONTENT WERE SUBMITTED TO THE PIN-DISC TEST USING SANDS WITH GRANAS # 220 AND # 320. FOR EACH COMPOSITION THREE 3.0 MM BODIES OF PROOF WERE SUBMITTED TO THE TEST UNDER A 4.6N LOAD AND 0.35MM / MIN SPEED. AND DISC ROTATION OF 66 RPM THROUGH A 16.95 M PATHWAY THE RESULTS OBTAINED THE TREND OF THE INFLUENCE OF THE CARBON CONTENT PRESENTING A RELATIONSHIP IN WHICH GREATER CONTENTS HAVE A LESS EFFECT OF WEARING, DIFFERENTLY DIFFERENT IN SUCH DIFFERENT DAMAGES. OF SIGNIFICANT ENCRUUATION, WHERE HARDNESS GAIN HAS BEEN OBSERVED IN STEELS WITH LOWER CARBON CONTENTS. HOWEVER, A SWING OF THE EFFECT IN ABRASIVE # 320 WAS PRESENTED. THE MICROGRAPHS REVEALED MICROSSULCES FROM THE TEST AND DIFFERENCES WERE NOT OBSERVED IN THE WEAR BRANDS WHEN DIFFERENT SIZES OF ABRASIVE PARTICLE ARE USED.

Abstract:

A low carbon steel alloy with Cr, Mo, Nb and B additions was subjected to various heat treatments on a pilot scale, in a muffle furnace, to obtain a multiphase steel with strength above 1200 MPa. The heat treatments consisted of heating cycles, soaking in an intercritical field and cooling to obtain the multiphase microstructure. The techniques of optical microscopy, scanning electron microscopy, folding test, tensile test and hole expansion test were used to evaluate the product performance. Then, tests were carried out on an industrial scale, on a hot dip galvanizing line, of the horizontal type, with an annealing furnace coupled, where the results obtained on a pilot scale were reproduced. The results obtained (resistance limit above 1200 MPa, yield limit above 800 MPa and elongation of the order of 10%) suggest that the product can be used in parts that require high anti-intrusion properties in the automotive and auto segments

Abstract:

The information of temperature and carbon during refining phase of the electric arc furnace is key for steelmaking process control. Immediate values from these variables are obtained by direct measurement with an immersed sensor on the bath that is disposed after use. The proposed model predicts the results of temperature and carbon by the variables of process state. There were gains on the reduction on the frequency of direct measurement and occurrence of production stoppages for adjustment of temperature of the electric arc furnace with direct impact on the operational cost and on a lower exposure of security risks of the sampling operation.

Abstract:

Abstract:

After the rupture of an iron ore tailings dam, a large forest area was affected with the mud affecting the entire ecosystem of the region. The need arose to dispose of all this mud somewhere and recover the entire degraded area. The quickest and safest way to solve this problem was to use a paralyzed pit with 40 meters of water depth to dispose of this tailing with a volume of approximately 11Mm³ with low environmental damage and risk of accidents. One of the conditions for using the pit to dispose of the tailings would be geotechnical monitoring to monitor the stability of the structure and safeguard the operators who will access the interior of the pit. The conditions for carrying out this work have the main role of monitoring / studying the stability of the pit. Due to the disruption, the pit was approximately one year without geotechnical monitoring and inspection, returning to activities at the beginning of 2020. For monitoring purposes, orbital radar, terrestrial radar, topographic survey and bathymetry were used in addition to monitoring the routine inspections. In the stability analyzes, the different scenarios were considered before the start of the disposal due to the variation in the water level and an increase in tailings at the bottom of the pit. Even so, subsidies were obtained during this monitoring period to verify that the pit is in favorable conditions for the disposal activities in the pit. The results of the stability analyzes were satisfactory, new analyzes will be carried out as the disposition work progresses. The estimated time for waste disposal work is approximately 5 years. Therefore, this monitoring and analysis work will be updated during the disposal time.

Abstract:

Structural steels are the most used in civil construction due to toughness, microstructural homogeneity, good weldability and ductility, in addition to the relatively low cost compared to microalloys one. Steels such as ASTM A36 are used in buildings, bridges, machinery, ships and different components. In these steels the chemical composition is restricted to carbon, silicon, manganese, sulfur and phosphorus. Nowadays, the reduction of sulfur content is an important objective to increase toughness and improve mechanical properties. In this research, to evaluate the effect of sulfur, ASTM A36 steel coils with different levels of this element were selected. Samples were taken from the coils for hardness measurements. Later they are made specimens to be subjected to tensile tests, in longitudinal and transversal lamination directions. The microstructure of one of these samples was characterized to compare with a commercial ASTM A36 steel. To determine the variation in the amount of sulfides in relation to the sulfur content, thermodynamic simulation with the FactSage software was used. The results show that the variation in the sulfur content did not influence the mechanical strength, although with the sulfur increase there is a slight reduction in the elongation values.

Abstract:

Microalloyed steels containing small amounts of carbide-forming elements such as molybdenum, niobium, vanadium, and titanium. The effectiveness of carbides depends on the size and precipitated volumetric fraction and is responsible for improving the mechanical strength by grain refining and precipitation hardening. To determine the quantity and different carbides, software such as FactSage is often used, which is integrated to the thermodynamic information of liquid and solid metallic solutions, oxides, nitrides and carbides. The FactSage allows to evaluate the quantity of precipitated carbides on cooling or heating during the wrought process. In this context, it is important to emphasize the importance of molybdenum in the phase transformation and carbides precipitation at different temperatures. Then, the objective of this research was to simulate the effect of molybdenum considering the contents of 0.09; 0.12, and 0.15% of this element in a microalloyed steel, with defined chemical composition. The simulation, was performed with the FactSage and varying the temperature from 300 to 1400 ºC. The results show that M23C6 carbides are more stable than MoC and M7C3, in addition, they are the main responsible for secondary hardening. However, after coalescence, the predominant phase is cementite, which remains stable until the start of austenitization.

Abstract:

The duplex stainless steel UNS S32205 was cold rolled and annealed at 900 °C, 1000 °C and 1100 °C, during 180 s, aiming the grain refining. The objective of the work is to evaluate the influence of thermomechanical treatment on microstructural evolution, phase distribution, mechanical and corrosion resistance. For this, microstructural analyzes were performed using optical microscopy (MO), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The mechanical and passive properties were measured by tensile tests and electrochemical impedance spectroscopy (EIS) technique, respectively. The sample as supplied showed low strength and high ductility, and less resistance to corrosion when compared to the annealed samples. After cold rolling, a decrease in passive properties and possible formation of strain-induced martensite (SIM) is observed. Annealing at 900 °C resulted in sigma phase precipitation, decreasing the ductility of the sample. No significant changes were observed in the charge transfer resistance of the annealed samples.

Abstract:

Selective Laser Melting is an additive manufacturing process (AM) in which the selective fusion of a powder bed is carried out, this powder being often imported and predetermined by the manufacturers of the equipment used. This work aimed to produce parts by MA from maraging 300 steel powders produced nationally through gas atomization. Analyzes by SEM and XRD of the powder and a visual evaluation of the integrity of the parts produced by AM were carried out. It was possible to obtain powder samples with particles of spherical and irregular morphology with sizes from 5 to 80 µm. There was a visual integrity of the pieces produced by AM and the process took place without interruptions. It was concluded that the particle size was in agreement with the literature and, according to the results of the AM process, there is evidence that the parameters and powder used were adequate for the process.

Abstract:

NiTi alloys are well known for their functional properties, such as shape memory effect (SME) and superelasticity (SE). However, there is a great difficulty in producing intelligent devices through traditional thermomechanical processing routes. In this sense, advanced processes involving additive manufacturing (AM) and powder metallurgy have been improved to solve this problem, among which, the selective laser melting (SLM). Elementary powders of Ni (oxyreduction) and Ti (hydration-dehydration), of high purity, were used for in-situ production of the NiTi alloy by SLM, using laser power of 125 and 150 W and energy density of 25, 35 and 40 J/mm3. The characterization of the manufactured parts was carried out by optical microscopy and scanning electron microscopy using a backscattered electron detector and semiquantitative chemical analysis by energy dispersion X-ray spectroscopy. It was observed that the energy density is inversely proportional to the occurrence of pores and cracks. The combination of 125 W - 40 J/mm3 parameters presented the most promising results among the analyzed conditions.

Abstract:

According to ASTM, additive manufacturing is defined as a process of joining materials capable of producing objects from a 3D model in which layer-by-layer deposition occurs. This process is revolutionizing the manufacturing industry due to its ability to obtain almost finished products in a short time with almost no material waste. In this work, the WAAM - Wire Arc Additive Manufacturing process is being used, which is based on the fundamental concepts of the automated welding process, such as Gas Metal Arc Welding (GMAW). The synthesis of the material used a gas flow of 15 L/min with a composition of 97.5%v Ar and 2.5%v CO2 and 316L stainless steel wires with a diameter of 1.2mm that are deposited layer by layer and a solution with Al2O3 and isopropyl alcohol was also prepared, which was applied with the help of a brush between the deposited layers. Welding tests were carried out with different voltage values, welding speed and wire speed and thus defined those that produced a weld bead with the best visual aspect, which were the following parameters: voltage of 21V, wire speed of 11.6 cm/s and welding speed of 900mm/s and 1200mm/s. With these values, the best deposition strategy for the manufacture of the product was defined. The following tests were carried out: tensile strength tests according to ASTM E8 in different directions to evaluate anisotropy, hardness tests, X-ray diffractometry in the different weld layers and in the cross sections to analyze the phase distribution and the crystallographic texture generated in the process and a microstructural analysis was also performed with SEM images and optical microscopy.

Abstract:

The aim of the present study is to observe the microstructural modifications in green bodies pressed by mechanical alloying (MA) with Ni elemental powders obtained by oxidation-reduction and Ti HDH (hydrated-dehydride), through the reactive sintering process using a Yb:Fiber laser source. The processing was done using a Yb fiber laser with 2 mm in diameter, in order to evaluate the reaction exothermicity and the laser-powder interaction. It was observed the parameter modifications effect such as power (40 to 200 W) and laser scan speed (4 to 6 mm/s) on the structural changes of the samples, inquiring the occurrence of ignition for reactive sintering and the level at which it occurred in the extent of the thickness of the sample. Optical microscopy and scanning electron microscopy techniques were used to observe the sintered bodies in regions that comprises the beginning and end of the laser scan, it was verified the presence of three distinct regions: the beginning of the scan, showing only the punctual action of the laser; an intermediate transition segment, which sets the ignition of reactive sintering; and the final region, characterized by the effect of energy propagation.

Abstract:

The present study evaluated the initial stages of conventional sintering alloys, oxidizing atmosphere, based on Ti-Nb system with 8.34 and 25.57%at.Nb, using Ti and Nb elementary powders from the hydration-dehydration (HDH) process, which involves a lower cost process and raw materials for the production of these alloys. The evaluation of theoretical and experimental densities (Archimedes Principle) highlighted important characteristics about the initial mixture of Ti and Nb powders with different particle sizes, corroborating with the results obtained from the Scanning Electron Microscopy and X-Ray Diffraction analyzes - by the initial formation of the TiNb intermetallic between the Ti and Nb particles associated with some oxides and suboxides.

Abstract:

In the present work, the instrumented ultramicrohardness test that explores certain mechanical properties was explored, to assess whether there are changes made due to the change in the microstructure of steel. The conditions analyzed were as a premium for Hot Rolling (HR) and Cold Rolling (BFH), as well as Intercritical Continuous Annealing (BFF) in the industrial production of “Dual Phase” (DP) or biphasic steel. Among these differences, the phases are one of the main changes in the microstructure, as in Hot and Cold Rolled conditions they have free ferrite and second phase (main constituents are divided into perlite, bainite and some tiny fraction of martensite-austenite constituent - MA), but differ of the free ferrite without deformation in the HR condition, whereas in the BFH condition, the ferrite, be it free ferrite, ferrite contained in the pearlite or ferrite contained in the bainite, is hardened. In the condition of Continuous Intercritical Annealing, it presents free ferrite (both with hard-grained and recrystallized grains in a larger fraction) and the second phase (main constituent MA), characterizing the microstructural aspect of a DP steel. Thus, because BFH has a very large concentration of hardened ferrite, it is to be expected that its hardness, mechanical strength and yield limit is greater than that of BFF and HRC. With the results of the instrumented ultramicrohardness tests, it can be seen that BFH had greater Vickers, DHV-1, DHV-2 and Hit hardness, confirming that it has greater hardness, mechanical resistance and yield limit. And yet, after analyzing the results obtained in each mechanical property, the identification module is shown to be the most sensitive, with the elastic ratio being the least affected among the three changes studied. Therefore, the tests proved that the ultramicrodurometer is a tool with the ability to present an acceptable prognosis to determine the mechanical properties for such steels.

Abstract:

This work aims to study the influence of deformation temperature and strain applied on the Reverse Strain Induced Martensite Transformation (RSIMT) of ferrite into austenite in a superduplex stainless steel. It was found that increasing applied plastic strain leads to reduction of the ferrite content without formation of other phases than austenite, which corroborates the RSIMT hypothesis. However, the cryogenic rolling temperature did not affect the phase transformation, which occurred in the same manner as the rolling at ambient temperature.

Abstract:

This work evaluated the grain growth kinetics in a UNS S31803 duplex stainless steel (DSS) during solution heat treatment. DSS sheet was cold rolled to a 50% thickness reduction, and after that, three series of samples were subjected to solution treatment at 1050 °C, 1100 °C or 1150 °C in times up to 96 h. Both grain size and surface areas between phases (Sv) were determined. Mean intercept length measurements showed differences between ferrite and austenite in respect to the grain growth kinetics and grain morphology, and Sv measurements have shown that the surface area diminishes with the increase of the solution heat treatment temperature and/or duration. Ferrite is the phase that commands the global grain growth, since ferrite grain growth has the highest activation energy (77.8 kJ/mol) when compared to the activation energy for grain growth of austenite (55.4 kJ/mol).

Abstract:

Structural masonry is one of the most constructive alternatives employed in Brazil. In this system, the wall, which is formed by blocks joined with mortar, acts as structure function. For such construction process, the mortar bedding type can be decisive in the production and the yield of the work. Two types are recommended, full bedding, covering net área for unit and face sheel bedding, where the mortar is placed only in the face shell area of the block. This work aims to evaluate the effect of the mortar bedding type on concrete masonry prisms, observing the compressive strengths and their respective rupture modes. It is concluded that the face shell bedding presents less compressive strength than the full bedding and rupture by separation of the block, while the other type has rupture by combined.

Abstract:

The Campos dos Goytacazes’ city where this studies was realized has the sugarcane production as a shocking factor on your growth and your economy. The present study has as objective the comparation between the conventional concrete and a concrete with a partial replacement of the Porland cement by the sugarcane bagasse ash. In the unities of 20% and 40%, aiming proporcionate a vailable substitute to the Portland cement why it apresentates in your production the generation of environmental impacts by the

Abstract:

The Campos dos Goytacazes’ city, in interior of Rio de Janeiro state, where this studies was realized has the sugarcane production as a shocking factor on your growth and your economy. The present study has as objective the comparation between the conventional concrete and a concrete with a partial replacement of the Porland cement by the sugarcane bagasse ash. In the unities of 20% and 40%, aiming proporcionate a vailable substitute to the Portland cement why it apresentates in your production the generation of environmental impacts by the

Abstract:

The industrial process produces by-products over the life cycle. The sugar cane’s production presents itself as a economically important factor, in Brazil, since the XVIII century where the southeast region bring the follow by-products: straw ash, wet bagasse that generates energy, sugar, alcohol and sugar cane bagasse ash. In the civil construction – section responsable by large cemente consumption – the necessity of alternatives technologies have been grown over the years because changing in the way of thinking by the population. In the recycle sphere, researches has been realized in order to recycle by-products increasing your life cycle, reducing the costs of ejecting residues and achiving zero waste. This article treats of bibliographic review about the sugar cane bagasse ash utilization in concrete production. This review was realized from published stories in Brasil and in the world with the objective of bringing the information, caractheristic and properties of this concrete. As a result of this study there is a conclusion that the sugar cane bagasse ash utilization presents benefitis when classified as pozzolana possibiliting your utilization in substitution to structural and not structural finality.

Abstract:

It is essential to promote the development of the construction industry in a sustainable manner, prioritizing the rational consumption of inputs in the form of aggregates. Therefore, the use of industrialized mortars with the potential to reduce the generation of solid waste and prevent the loss of raw materials stands out. This article studies and compares the logistical and physical chemistry characteristics between conventional and industrialized settlement mortars. The parameters of transport, storage, preparation site and dosage of the material used were evaluated. In addition, the results obtained in the literature for tests on both types of mortar in the fresh and hardened state were evaluated, with an emphasis on the tests of flexural tensile strength and compression strength. Through this analysis it was possible to understand that industrialized mortar is capable of reducing losses, reducing costs and improving quality control, once it is dosed in the factory and made available in single bags. As for the physical aspects, both mortars are considered viable respecting the parameters of each field work.

Abstract:

The Construction industry in the world has sought to build more efficient systems in order to increase productivity, reduce waste and meet a growing demand, embedding itself in this frame steel structures. Through the presentation of concepts, advantages and disadvantages, we will study the technical and economic feasibility of a commercial structure in the steel at Faculdade Redentor, Itaperuna, Rio de Janeiro, comparing with the conventional building system, reinforced concrete cast. To do so will produce a budget structure of a steel building compared to a building with reinforced concrete. After the presentation of data will be discussed the costs of these structures, taking into account the benefits of each enterprise for the purpose of verifying that a building in the metal structure is viable or not. In this project there is also the use of structural steel is feasible technically and economically, due to the advantages offered by this construction material.

Abstract:

Semiconductor companies, after carrying out their encapsulated chip manufacturing process, generate solid waste. Some of these residues are predominantly composed of high purity silicon free from contaminants. The objective of this work was the physical, chemical and mineralogical characterization of the solid residue from the backside grinding of electronic grade wafers, through analyzes such as laser particle size, X-ray diffraction, FTIR-ATR and SEM-EDS. The majority presence of Si was identified, together with SiC (from the abrasives) and SiO2 (due to the surface oxidation of silicon during the process), in an average particle size of 7.98 ± 4.12 µm. From the data, potential uses of silicon as a co-product for other industries were identified, highlighting the applications in thermoelectric materials, hydrogen production and the use in the development of lithium-ion batteries.

Abstract:

Port activities generate huge amounts of waste of different types and shapes. One of the most common port activities is the export of iron ore, this is verified in the municipality of São João da Barra - RJ which has a port that exports this material from Minas Gerais, which arrives in a saving format and after the process of filtration, is shipped to its destination. Therefore, the objective of this work is to evaluate the influence of the addition of the waste resulting from the filtration process on the properties of the fresh state of mortars. Proportions of 0, 25, 50 and 100% of the waste were incorporated into the sand mass for consistency assessment, incorporated air content and water retention. The results showed that the addition of the waste caused an improvement in the properties in proportions of up to 50%, and in values above some properties are below the indicated values

Abstract:

Ports generate considerable amounts of waste, which vary according to their main activity. The municipality of São João da Barra - RJ has a modern port that is responsible for the export of iron ore, which reaches the format of savings, where it is benefited for later export. Therefore, the objective of this work is to evaluate the influence of the addition of the waste resulting from the filtering process on the properties of the hardened state of mortars. The waste was incorporated into the sand mass, in the proportions of 0, 25, 50 and 100% for the evaluation of water absorption by capillarity, mass density in the hardened state and mechanical resistance to flexion and compression. The results showed that the addition of the waste caused an improvement in all properties of mixtures of 25%, which can be used in some cases up to 50%, and in higher percentages the use is advised against.

Abstract:

The development of new building materials in general takes into account only technological factors, such as mechanical strength and applicability, but factors related to the durability of these materials are still little explored. The exposure of the new materials to aggressive environments, such as coastal locations and the interference of bad weather, impairs the stability and use of the materials. The objective of this work was to evaluate the durability of mortars incorporated with the waste of the iron ore port activity, under the condition of exposure to salt fog and wetting and drying cycles. For this, the prismatic specimens were subjected to exposure to the simulated saline environment and in standardized wetting and drying cycles. The results showed that the incorporation of port waste reduced the deleterious effect of exposure environments on mortars, enabling its application in civil construction

Abstract:

The use of natural fibers in cementitious materials has been gaining ground in recent years thanks to studies related to its surface treatment, which guarantee durability to new materials, in addition to the issue related to the large amounts of fibers that Brazil produces, such as coconut, which are discarded in landfills and dumps. Therefore, the objective of this work was the development of an ecological mortar with the addition of coconut fiber treated in NaOH solution in different proportions (2, 4 and 6%) in relation to the cement mass. The properties of these mortars were evaluated, such as their consistency, incorporated air content, water retention and mechanical resistance (compression and flexion) according to Brazilian technical standards. The results showed the addition of fiber improves technological properties, such as strength, with percentages of 2% being the most recommended for civil construction applications

Abstract:

In order to seek more sustainable alternatives in civil construction, both in the structures as a whole and in the existing building materials, with regard to the durability and quality of its components, this article describes the production of soil-cement blocks manufactured with dam soil of tailings with addition of sisal evaluating the mechanical resistance and water absorption of the evaluated blocks. The addition of sisal, a natural fiber, to the block also favors preservation of the environment since it is included in the list of alternative materials. Through laboratory tests proposed in NBR 6457 (2016) - "Preparation for compaction tests and characterization tests", the composition of the soil used was characterized and the mechanical resistance and water absorption of the block made with sisal is proven to be suitable for its application for construction of buildings for civil construction. Thus, it was concluded that this block is suitable for use in civil construction, being a more sustainable product when compared to the conventional soil-cement block.

Abstract:

In this work, the use of Natural Lignocellulosic Fibers in polymeric composites for application in ballistic systems is discussed. These fibers, with the aid of techniques that improve their mechanical properties, such as reinforcement architectures and treatments that increase the adhesion to the fiber-matrix interface, are viable options for ballistic protections and have satisfactory results in this field of study. The characterization of natural sisal fiber was made from x-ray diffraction, allowing the calculation of parameters such as the microfibrillar angle and the crystallinity index, which are important values for the direction of the mechanical functioning of these fibers. For fiber and sisal tissue, the microfibrillar angle was 7.68º and 6.89º, respectively, and a crystallinity index of 40.44% for the tissue. We also analyzed the appearance of a peak not commonly found in the amorphous region of the sisal XRD, in the 12.5º region of the diffractogram.

Abstract:

The ballistic resistance and microwave absorption of a composite of aramid fabric impregnated with polyethylene glycol and hematite nanoparticles was investigated for different hematite concentrations between 0 and 17 wt%. Different damage and energy absorbing mechanisms during ballistic impact were identified: cone formation on the back face of the target, tensile failure of primary yarns and deformation of secondary yarns. In terms of energy absorption, the best results were achieved with 7 wt% hematite, while the smallest depth of penetration (DOP) was observed for a composite with 9 wt% hematite. A scanning electron microscope (SEM) image of the composite with 7% hematite after the ballistic test showed that the main energy absorption mechanism was deformation of secondary yarns. The microwave absorption was measured using the waveguide technique in the frequency range from 8 to 12 GHz. The results showed that the dielectric loss ɛ”/ɛ’ is maximum for a concentration of 3% hematite, while the magnetic loss µ”/µ’ is maximum for a concentration of 11 wt% hematite. A reasonable compromise between ballistic resistance and microwave absorption seems to be a composite with 7 wt% hematite.

Abstract:

The energy absorption of alumina-epoxy composites with 10, 20, 30, 40, 50, 60, 70, 80 and 90% wt% alumina in ballistic tests was investigated. The tests were carried out at subsonic speed using a compressed air rifle. The results showed that the composite with 30% alumina yields the best results. Scanning electron microscopy (SEM) images of this composite showed intragranular and intergranular fracture, suggesting a high adhesion between alumina and epoxy.

Abstract:

The Caranan plant (Mauritiella Armata), unknown to the literature in terms of engineering, had its fibers investigated from this work. This study presents systematic results on the structural characterization of the Caranã fiber. These natural lignocellulosic fibers (FNLs) were subjected to Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) tests and in addition one hundred fibers were evaluated to verify their diameter and density.

Abstract:

Different ranges of diameters of the Caranã fiber (Mauritiella Armata) were investigated to discover how the relationship between them influences the mechanical properties of traction. For the first time in the literature, this information was studied according to the ASTM D2101 standard, applying Weibull's static analysis that determined the characteristics and reliability trends of the tensile test of this natural lignocellulosic fiber (NFL). The results indicated that the highest tensile strength was obtained for the finer fibers.

Abstract:

The access to drinking water, which according to the United Nations (UN), is an essential human right, unfortunately is not a reality for everyone. Graphene membranes can be allied in this process, being used for nano-filtration of water; the study of this material is the objective of this work. Reduced graphene oxide membranes were produced using the spray coating method and characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, permeability and desalination analysis techniques. It was observed that the technique was able to produce continuous and uniform graphene membranes, the rejection capacity was considered below the desired for Na2SO4 and NaCl, which indicates that other salts, should be evaluated.

Abstract:

Water scarcity is an ancient and growing problem for humanity. Until this moment the, most promising technological solution has been the use of polymeric membranes; however, this technology seems to be close to the limit, alternative materials such as graphene and its derivatives have been studied to compose the next generations of membranes. Thus, this work aims at the synthesis of a lamellar reduced graphene oxide (rGO) membrane, as well as to evaluate its potential use and present challenges.

Abstract:

The Ceramist industry is responsible for the inappropriate disposal of millions of tons of waste, resulting from failures in its production process, in the environment. In order to seek an alternative use of this material, aiming to reduce the environmental impact of ceramic production, this work aimed to evaluate the technical feasibility of using residual ashes from ceramic industries in mortars, as a partial replacement of Portland Cement. For this, three mortars were made in the mix 1: 1: 6 (cement: hydrated lime: sand), the first used as a reference, without the presence of residue, and finally, mortars using 5 and 10% of residual ash from ceramic production , respectively. The mortars were subjected to the tests of Consistency Index, Water Retention and Mass Density and Incorporated Air Content, by which it was found that the presence of the residue contributes to the increase in the water retention of the mortar, as well as to the increase of density and the decrease in the air content incorporated into it. Furthermore, it does not represent damage to consistency, although it does not promote significant improvement of this characteristic. It was therefore possible to conclude that the use of residual ash from ceramic production as a partial replacement for Portland cement in mortars does not harm the physical properties of the mortar in its fresh state.

Abstract:

With the advent of nanotechnology, the importance of studying and developing new nanostructured materials and their combinations is evident. Graphene is currently the focus of several technologies due to its excellent properties, which enable its use in several applications, be they supercapacitors, biomaterials, antibacterial materials, solar cells, batteries, etc. As it is a material of amphiphilic character, its combination with other nanomaterials provides new attributes, as well as the achievement of desired properties. Ferrites, as well as copper ferrite, have ferrimagnetic properties, storage, antimicrobial, biocompatible in addition beging a ecofriendly low impact on the environment, being ideal candidates for evaluation and enduring synergistically with graphene. Therefore, this study aimed to evaluate, by FTIR, a copper ferrite nanocomposite based on reduced graphene oxide. In this study, it is possible to observe the presence of both copper and iron, as well as the confirmation of the reduction of graphene oxide.

Abstract:

Some polymers degrade by hydrolytic processes, generally resulting in low molecular weight species that can be metabolized or bioabsorbed by the body. The human physiological environment offers the right conditions for these hydrolytic processes, the hydrolytic degradation test regulated by ASTM D1635 is of low cost, allowing evaluations of the properties of the previous ones to the degradation process, under controlled temperature and pH conditions. This work aimed to evaluate the hydrolytic degradation by the in vitro method of biocomposites with polymeric matrix PHB (Polyhydroxybutyrate), bentonite clay and compatible agent, PP-g-MA. The compositions were mixed by extrusion and the specimens were coformed by hot pressing, the samples were also evaluated by Optical Microscopy (MO) before and after the hydrolytic degradation tests Under optical microscopy, more regular surfaces without press marks can be observed as a result of the addition of clay and diffuse surface degradation of all compositions, especially PHB1. The PHB3 sample showed a possible formation of clusters and compositions PHB1 and PHB3 reached the erosion stage.

Abstract:

The objective of this work was to investigate the toughness behaviour of epoxy matrix composites reinforced with up to 30% by volume of ramie fabric with 0.5% vol. Graphene oxide (GO), through Charpy impact tests. The addition of GO results in a visible improvement in the energy absorption capacity of the composites. The macroscopic observation of post-impacted samples and the analysis of fractures by SEM showed that the longitudinal rupture through the interface of the ramie fiber with the epoxy matrix is the main mechanism for the greater toughness served by these composites. In addition, it found better adhesion between the ramie fiber and the epoxy matrix due to the incorporation of GO.

Abstract:

The graphene oxide (GO) was used to improve the properties of polymer compounds. The epoxy matrix compounds with ramie fabric (Boehmeria nivea) already obtain these technological techniques due to their good mechanical results. The objective of this work was to investigate the toughness behavior of epoxy matrix compounds with 0.5% GO, reinforced with 30% by volume of ramie fabric by Izod impact tests. The addition of GO results in a visible improvement in the energy absorption capacity of the compounds. A macroscopic observation of post-impacted samples and an analysis of fractures by SEM shows that a longitudinal rupture through the ramie fiber interface with an epoxy matrix is the main mechanism for a greater toughness served by these composites. In addition, there was a better adhesion between a ramie fiber and an epoxy matrix due to the incorporation of GO.

Abstract:

Geopolymers are inorganic materials, aluminosilicates that are produced by geopolymerization reaction. Due to their superior properties and characteristics to Portland cement, many researches are carried out to ensure the importance of geopolymer material in civil construction. In view of this, the objective of this study is to produce geopolymeric pastes with different blast furnace slag (EAF) formulations, and later subject them to temperature variations, to then analyze the morphologies of the specimens after fracture. For this study, Metakaolin, high slag (EAF) with formulations of 0%, 35%, 45% and 55% were used, and potassium hydroxide (KOH) and sodium silicate (Na2SiO3) were used as activating solution. Subsequently, the specimens obtained were submitted to 300 ºC and 800 ºC. To achieve the objective of the study, Optical Microscopy (OM) and X-Ray Diffractogram characterizations were performed for the geopolymer and blast furnace slag, respectively. Thus, the results showed that the specimens with formulations of 45% and 55% were superior to the others when subjected to 800 ºC, as they result in a smaller amount of pores and less when the material is unreacted and cracks.

Abstract:

Composite materials are of great interest in other areas of science, due to the vast field of applicability and workability. In this sense, natural fibers and industrial waste are raw materials with good performance for the production of a composite material. Thus, the objective of this study is to evaluate the mechanical and morphological behavior, after the tensile test according to ASTM D638, of a hybrid composite of 25/25% of 15 mm sisal fiber and Marupá particulate in polyester matrix, with cure rate of 0.33%. Subsequently, characterize the raw materials by Scanning Electron Microscopy and morphologically characterize the hybrid composite after the tensile test. The results for sisal fiber morphology indicated a regular geometry, with absence of layers. The Marupá particulate, on the other hand, highlighted a more irregular, heterogeneous morphology. The results for the hybrid composite highlighted the tensile strength of 25.70 Mpa, about 30% reduction compared to the pure matrix of 50.24 Mpa. The fractographic appearance revealed the presence of pull out, fiber scratching and the presence of wood particles. Finally, the composite obtained good performance in relation to the other composites studied, being able to present itself as a material with good performance.

Abstract:

Composites are important materials for the development of new products for certain applications. These materials are composed of phases/microconstituent, which determine the properties and characteristics of the final product. Natural jute fiber has good mechanical properties, strength and is a renewable, biodegradable and economically viable reinforcement. On the other hand, wood residues, in turn, constitute a good reinforcement to the matrix, adhering exponentially. Therefore, the objective of this study is to evaluate the tensile properties of a hybrid composite of 25/25% of natural jute fiber and marupá wood residues, in a polyester matrix methyl - ethyl - ketone of 0.33% (v/v ). Subsequently, the hybrid composite was subjected to tensile testing, according to ASTM D638, and fractographic analysis by scanning electron microscopy. Thus, the results showed that the composite presented an average tensile strength equal to 25.13 MPa, with only 31.54% reduction when comparing the strength of the pure Matrix. The fractrographic aspect showed the presence of porosity in the material and pull out. Thus, in function of the mentioned characteristics, the hybrid composite presented a good performance, compared to the pure matrix.

Abstract:

Composite materials have gained prominence due to their association with excellent technological and environmental characteristics. In this sense, the development of polymeric matrix composites stands out, highlighting the application of waste in composites. The development of composites emerges as an alternative for the environmentally correct final disposal of different wastes as well. Thus, the objective of this work is the production of composite materials with an unsaturated polyester matrix, with a methyl ethyl ketone peroxide (MEK) curing agent, in the presence of quaruba wood residue and manually cut sisal fiber. The wood residue and fiber were randomly disposed in the polyester matrix and the manufacturing process was by manual molding and without pressure. The mechanical property evaluated was through a tensile test in accordance with ASTM D 638:2010 standard. After the tensile test, Scanning Electron Microscopy (SEM) was performed aiming to analyze the fracture surface in order to establish a relationship between the aspects of the fracture with the mechanical properties. The results showed that the methodology applied as satisfactory, mainly due to revealing innovative data about this composite, the presence of sisal fibers is accompanied by voids due to the presence of pull out.

Abstract:

In order to satisfy the needs of societies in the best possible way, when carrying out engineering activities, one should consider not only the economic and technological aspects, but also their environmental impacts. Thus, the development of composites that use waste as a cargo has grown, aiming not only for better and / or cheaper materials, but also to reduce the use of natural resources and the non-use of waste. This work aims to compare the effect of processing coconut shell particulates on the impact resistance of epoxy matrix composites. The processing evaluated in this work was carried out in a ball mill of the brand Servitech, model CT-240 / A, while the results were obtained by means of an Izod type test, carried out in a PANTEC Pendulum impact test machine, model XC -50. The results of this work indicate that the use of particulates without processing is detrimental to the performance of composites, while using processed particulates it is possible to increase the resistance to impact. It was also noticed that the processing facilitates the process of making the specimens, in addition to enabling the use of higher volumetric fractions.

Abstract:

The main solid residue of the coconut is its shell, with fibers being the most valuable part of it. However, when extracting the fibers, a particulate by-product with twice the volume is generated. This work aims to evaluate the difference between the compressive properties of composites with incorporation of this by-product before and after its processing. This residue was processed in a ball mill of the brand Servitech, model CT-240 / A and incorporated in an epoxy matrix of the DGEBA / TETA system, varying the volumetric fractions of the residue. The results indicated that in addition to allowing higher volumetric fractions of particulates to be used, the processing of coconut shell powder is beneficial for the properties of the composites and the dispersion of the particulates. Regarding the compressive strength, it was possible to obtain results superior to pure epoxy and composites with unprocessed particles. However, although it is not possible to obtain a higher modulus of elasticity than pure epoxy, the charge processing allows to obtain values closer to it.

Abstract:

Since the last decade, several studies have been carried out regarding the use of natural lignocellulosic fibers (NLFs) as reinforcement in polymeric matrix composites for ballistic application. The reported results are promising and can often be compared to those using traditional materials like KevlarTM, especially when applied as an intermediate layer in a multilayer armor system (MAS). However, studies on the most suitable configuration for polymeric composites reinforced with NLFs when subjected to high strain rates still needs better understanding. This work aims to evaluate four possible arrangements for epoxy matrix composite reinforced with NFLs in terms of energy absorption and ballistic efficiency. In this study, the NLF chosen was the piassava fiber, which is a rigid fiber and therefore cannot be woven as fabric. The performance of these composites was assessed against the ballistic impact of 7.62 mm high-energy ammunition. The results obtained were analyzed statistically using analysis of variance (ANOVA) and Tukey's honest significant difference test (HSD). In addition, the micro-mechanisms associated with the failure of these composites were determined. Energy absorption of the same order as KevlarTM and indentation depth, way below the limit determined by NIJ 0101.04 standard, were obtained for all conditions.

Abstract:

Concrete is the most used material in civil construction. To meet certain requirements, several studies were carried out to improve this material. Thus, high-performance concrete emerged, with a special emphasis on Reactive Powder Concrete (RPC). RPC is a composite material consisting only of materials of low particle size and, in some cases, fibers are inserted to improve its performance. In light of this context, this work aims to evaluate the influence of the steel fiber content on the mechanical properties of RPC. The experiment consisted of producing four mixtures of RPC from the same mix, one without the addition of steel fibers and the other three changing the dosage of steel fibers over the cement mass. The molded specimens were stored in a curing tank, where they remained until the age of the tests. The 3-point flexion and compressive strength tests were performed at the ages of 1, 3 and 7 days. It was observed that 10% content of steel fibers showed the best strength gains, either in tensile, flexion or compression. In addition, there was a significant improvement in the ductility of the composite, from fragile rupture to a ductile rupture, due to the presence of steel fibers.

Abstract:

The research developed polymeric/geopolymer composites to observation electrical conduction capacity. Geopolymer materials were produced with steel slag and expanded graphene into the polyamide 9T (Genestar™, Kuraray) matrix under melt state. The geopolymer was synthesized using steel slag - industrial reject of steal production - and sodium metasilicate by constant mechanical agitation. Posteriorly, the material was dried in an oven, and after the dimensions of geopolymer particles were decreased through pressing in a hydraulic press. A modified Hummers method was applied to obtain graphene from graphite. The composite was obtained by processing in a double screw extruder, allowing higher and better dispersion between the composite materials. Initially, the resulted composite materials were characterized through thermogravimetry, X-ray diffraction, and X-ray fluorescence spectrometry. Preliminary results presented some differences according to similar studies found in the literature. The composites did not present some loss of thermal stability, crystallinity content, and elementary composition of the geopolymer showed with X-ray fluorescence analysis (Si, Al and Fe), suggests the development of materials with future applications in electronic apparatus by materials engineering.

Abstract:

The study proposes the development of a new composite in order to apply in the aerospace industry, where the demand for light and versatile high-performance materials has been promoting both research and use of polymeric composite, which can reach or surpass the performance of traditional materials such as metal. The composite matrix used was the semi-aromatic polyamide PA9T, a new thermoplastic polymer with high heat and chemical resistances, low water absorption, and a cost-performance higher than most materials in the market. Geopolymer particles from two types of slag (PAN and CON) were decreased, and then added to the polymer matrix through extrusion in order to improve mechanical properties. Then, the EDX, XRD, and TGA analyses were performed to present some characteristics of the different composites, which can contribute to innovation in aerospace technology.

Abstract:

The appreciation for coffee by Brazilians is notorious since it is common to consume it daily and the drink can be easily found throughout the country. Thus, used coffee grounds, the most common residue of this product, are generated in large quantities and discarded without much concern for possible contamination of the environment. Aiming a better final destination to the coffee grounds, the present work presents a compressive tests characterization of epoxy matrix composites reinforced with coffee grounds to be used as high performance coating flours (HPF). In this case, HPF is a type of floor covering that provides a good finish, low cost and, as the name suggests, high mechanical performance. Thus, the compressive strength of composites for this type of application is critical and is the main focus of this work. For this, specimens were produced reinforced with volumetric fractions of 10%, 20% and 30% of coffee grounds forming a composite with epoxy resin. After the matrix curing, the specimens were subjected to compressive tests. The results indicated that the 30% coffee grounds composites showed promising results for application as HPF, given the compressive strength and elastic modulus values required by standard, even if these values were lower of those of the pure resin.

Abstract:

The civil construction industry is one of the biggest raw material consumers on the planet. However, one of the advantages found in this industry is the possibility of incorporating different residues into its materials, reducing the environmental impacts produced by it, in addition to the possibility of developing new products. This research aims to evaluate the properties in the fresh state (consistency, density, incorporated air and water retention) of coating mortars, with a trace of 1:3:0.85 (cement: sand: water), with the Addition of açaí stone, an agro-industrial residue, as a partial substitute (10% by mass) of sand, in different processes: natural stone, calcined at 400ºC, treated with KOH and NaOH. The mortars containing the residue showed less consistency, with emphasis on the composition with NaOH with a reduction of 52%. Density also reduced in all mortars with the residue, presenting a lighter and more flexible material. The incorporated air content showed little variation in 0.3 and 0.2%. Finally, water retention showed an improvement in all compositions, especially those treated in KOH and NaOH, increasing this property by 11%. The addition of the seeds proved to be viable analyzing the properties in the fresh state of the material

Abstract:

The present work’s main goal is the development of artificial stone through vibration, compression and vacuum method, from quartz waste and glass waste from transparent packaging, agglomerated by epoxy resin. Wastes were prepared and distributed granulometrically by the fine sieving method. Subsequently, tests indicated that the most closed-packed mixture contained 33.33% of fine particles, 33.33% of medium particles and 33.33% of coarse particles and the minimum resin content was calculated at 15%. The artificial stone plates were prepared with 15 (RAVQ 15) and 20% (RAVQ 20) weight of epoxy resin by the vibration, compression and vacuum method (600mmHg for 20min at 90ºC and 10t of compaction pressure). The plates were sanded and cut to the appropriate dimensions so that tests could be performed in order to determine the physical indices (apparent density, water absorption and apparent porosity) and 3 point bend strength. The results are within the range of values found by other authors, in addition to being comparable to commercial artificial stone. Besides, they classified the stone produced as high quality coating materials.

Abstract:

The gradual replacement of conventional materials by composite materials becomes reality when specific properties cannot be achieved by them. A search is being made for new composites using natural fibers or a blend of natural fibers and synthetic fibers as reinforcement for environmental reasons. The study in question aims to develop two composite laminates, one based on piassava fiber fabric and another hybrid composite based on piassava fiber and E-glass fabrics, to compare the mechanical behavior of both. The laminated plates were prepared and processed for sample manufacture in accordance with the specifications of ASTM D3039 - Uniaxial Tensile Test and ASTM D790 - Three Point Bending Test. Scanning Electron Microscopy (SEM) was also performed to analyze the mechanisms of specimen damage.

Abstract:

This research consists of the production of concrete specimens with the addition of ground glass in order to improve its mechanical resistance to compression and also to be an outlet for the glass waste to be reused in civil construction. The research is justified to the problems faced in the disposal of glass, being a material that is currently considered one of the most problematic waste on the planet, the minimum time of total wear of the glass is 4 thousand years. Based on the addition of glass in the concrete design, cylindrical specimens conforming to ABNT were composed of cement, gravel and sand, with partial replacement in 0, 5,10,15 and 20% in ground glass. The glass residue was crushed by grinding and sieving with a granulometry of 2.36 mm mesh 8, the same granulometry of the sand used. From the compression tests after the curing of the specimens, it was observed that the addition of glass in the concrete gave a gain of 10.23% of the mechanical strength to the compressor 28 days of cure with 10% of glass, thus making possible the use of this concrete in the construction industry, efficiently estimating low cost for the use of a tailings. This work provides continuous research and development for further improvements of this composite

Abstract:

Brazil is a country in accession, and with that several sectors of the economy have been growing along with this advance. The foundry area is following this rise, with Brazil being the seventh largest producer of castings in the world, and this activity generates solid waste, the so-called green sand being the main one. The objective of this work is to replace the fine concrete aggregate with the foundry waste. The 3:2:1 line (sand: gravel: cement) was used to make the specimens, respectively. After verifying values obtained in a test with specimen without incorporation, dashes were made replacing with different percentages of foundry tailings. The specimens were cured at room temperature for 7 and 28 days, and immediately afterwards they were subjected to compression tests where they had a sheared rupture and different values of resistance limit (MPa). It can be concluded with this study that there is a feasibility of partially replacing the fine aggregate of the concrete with the foundry waste.

Abstract:

The most important prerequisite for mass production of sintered parts successfully is the high and consistent quality of the powder used, as its characteristics determine the behavior of the stages of compacting, sintering and, consequently, the properties of the finished product. This work consists of the characterization of Fe, Cu, Nb and NbH metallic powders that will be used, later, in the production of metallic matrices. The objective is to verify if the characteristics of interest such as purity, chemical composition, particle size, morphology, crystalline structure, apparent density and behavior to thermal stimulus are satisfactory for the good performance of the particles together during the stages of the production process via Powder Metallurgy. The experimental techniques employed in this evaluation were EDX, BET, MEV, DRX and TGA / DTA. It was observed that the particles of the metallic powders have satisfactory purity combined with a good particle size distribution and morphology. The crystalline phases were identified and the thermal behavior was adequate for the usual temperature range in the sintering of these materials. With this information combined with a controlled sintering process, we have a quality final product with expected mechanical and physical properties.