A high-arsenic contaminated acid derived from arsenical antimony fahlore(3Cu2S•As2S3) and enargite(Cu3AsS4) smelt process is one of the biggest hazardous wastes in nonferrous metallurgy (Cu, Ni, Pb, Zn, Sn, et al.) industry in China. Analysis of some enterprises discharge sewage acid arsenic content up to 5~10g/L in general, special circumstances as high as 20g/L, also high-arsenic contaminated acid had other harmful impurities. Limestone neutralization treatment for acid in an acidic nitrate medium pH(0~1)and elevated temperature(55~75¡æ)is described. Under the pH(0~1) arsenic still exists in the solution. Through the analysis XRD¡¢XRF of calcium sulfate, we found that the prepared samples have uniform crystallinity and fine crystalline, hadn¡¯t any other impurity. Then, the arsenic in the leaching solution can be further precipitated as a form of scorodite crystalline (FeAsO4•2H2O). In the precipitating arsenic reaction, in which ferrous ions were oxidized by air gas, the effects of acidity (pH), reaction temperature, air flow rate, the initial concentration of arsenic and the initial molar ratio of Fe(II) to As(V) on arsenic precipitation were investigated. The pH 1.0−5.0, Fe/As molar ratio of 1~1.5, the temperature of 50−90¡æ, and the air flow rate higher than 120L/h, under the test of precipitation, optimal parameter display more than 88% of arsenic could be precipitated as a form of scorodite crystalline.

The self-reducing technology for primary metals production presents great potential due to high reduction rate and high energy efficiency. The results should be high productivity and energy saving, contributing to the mitigation of CO2. Two processes are normally used to agglomerate the composite mixtures. One is the cold agglomeration, using cement as binder, which reacts with water forming a gel and after curing consolidates as a continuous phase covering the ore and carbonaceous particles conferring high mechanical strength. The main drawback is that needs a high content of cement, around 6 to 10%, increasing slag volume downstream, and at high temperatures, at 800 to 1000oC, the hydrates formed decomposes and strength goes down. Another process is “self-agglomeration, self-reducing”, that is, the coal of high fluidity is used as reductant and as binders. This type of metallurgical coal, by coking mechanism, consolidates as continuous coke phase after heating giving strength for agglomerates. There is no additional binder, therefore, results on less slag downstream, but it is not a cold agglomeration process. It needs to be heated before (ore and reductant) or after agglomeration to around 500oC or higher temperatures. The objective of this paper is to present the analysis, based on the literature, of possible alternatives of binder for self-reducing agglomerates and present preliminary experimental results.

In a previous paper of the authors, a new technology for producing iron and/or steel through a new self-organizing jet-emulsion technology and its unit SER was described. The purpose of this paper is to describe the basic principles of this technology.
The core of this process is based on the theory of self-organization and the principle of forced movement of two-phase working mixtures in a closed system under pressure which creates conditions for the deviation of the system from thermodynamic equilibrium. This way the system can change its end state to move on to the higher level of organization.
The above conditions are achieved due to a special design of the metallurgical unit. The main elements of the unit are a reactor-oscillator and a refining-settling tank (column reactor). This paper describes the physicochemical fundamentals of both reactor-oscillator and that of the refining-settling tank (column reactor)
Based on these fundamentals the new technology and its unit SER may be used to create energy-intensive small mini-mills containing an entire metallurgical cycle (from ore to steel) that can be mobile units with a fully closed energy loop and without crane equipment.

The presentation elaborates some Brazilian objectives and challenges regarding research and development for the mining sector, taking in consideration the Brazil-2030 National Mining Plan and the National Strategy of Science, Technology and Innovation 2016-2019, as well as the Strategic Plan of CETEM.

Using sulfur-bearing stone coal, the tin could be removed efficiently from cassiterite, But it was especially noteworthy that the volatilization ratio of tin was influenced by the ferrous sulfate in sulfur-bearing stone coal. Hence, the effects of ferrous sulfate on the reduction behavior of cassiterite need to be further studied. A new method for calculating the phases and phases formation temperature using FactSage software is described in this study. Ferrous sulfate and coal were used as reductants and a wide range of addition amounts were covered. The phases of roasted cassiterite with different proportions of reductants calculated by FactSage were consistent with those analyzed by XRD. The change trends of the equilibrium Sn amount calculated by FactSage also agreed well with those of onset of roasting measured by various analyses, i.e. XRD and chemical analysis. This new method is less labor-intensive and less costly compared with XRD and chemical analysis. Moreover, it also can provide prediction of roasting temperature range and proportions of reductants for tin remove from cassiterite.

The characterization of nonmetallic inclusions is very important for the production of bearings in order to improve the mechanical properties and service life. It's worth mentioning that large-scale oxide inclusions, such as aluminium oxide or calcium-aluminate, significantly influenced the fatigue life of bearing steel. Nonaqueous solution electrolysis method was employed to extract the non-metallic inclusions of bearing steel used for high-power wind turbines during electric steelmaking, refining, and rolling processes. By means of SEM and EDS, the morphology, size, composition, and type of the extracted inclusions were characterized and the possible sources of those inclusions were analyzed accordingly. The results show that oxide inclusions in this bearing steel are mainly composed of Al-Ca-Si-Mg system oxides. Additionally, these oxide inclusions, such as Al2O3-CaO-MgO-SiO2¡¢Al2O3-CaO-SiO2¡¢Al2O3-SiO2¡¢SiO2, existed in all samples, of which morphology, quantity, and composition changed in different processes. Even though the T[O] content in the rolled products is only 0.0007%, there still exists a certain amount of SiO2-rich Al-Ca-Si-Mg system macro inclusions.

Coal has globally been the most abundant fossil fuel resource. Even now, coal has a major role as a fuel for combustion. However, it is still beset with problems as an energy source in industrialized countries. The transition from petroleum oil to coal leads to the creation of more environmental problems. Besides coal is rather a less convenient source of fuel. There has in the past been continuous endeavours putting emphasis on coal to ensure a greater flexibility of energy supplies. The paper aims to critically review, analyse and discuss the status of several alternative and novel coal liquefaction, gasification and synthetic gas processes both from the source of carbon and energy. It has been utilized as both source of carbon and energy for power generation, cement plant and metallurgical units depending on coal qualities and properties. Coal quality depends on the type and rank of coal. Both depend on the chemical composition and macerals viz. Vitrinite, Inertinite, exinite and liptinite etc. present in coal. The Metallurgical coke, derived from destructive distillation of low- ash, low- sulfur bituminous coal besides contributing as a source of energy and carbon, as well provides strength to support the iron-making burden ascending through the blast furnace. Vitrinite reflectance plays a major role in ascertaining as to whether or not the coal can be used for coke making. Coke would offer adequate thermal strength during the chemical reaction under high temperature. The engineering systems involving these processes are beset with process complexities mainly in finding the proper coal rank and type. Of late large reserves of coal are found the world over. So the experience of the operators and the engineers still have a dependence of these processes on the performance characteristics of the coal. The characterization of coal will be another theme of the paper. It is, therefore, expedient to determine as to whether these coals could economically be utilised as a source of carbon and energy in some of the iron making processes including blast furnace. The paper seeks to examine the performance characteristics of coal and coke under conditions simulating some of the essential features of the blast furnace and directly iron making processes. It also discusses various aspects of coke making and blending processes vis-a-vis the desired physico-chemical properties of coal for an energy efficient and environmentally benign production units both for directly reduced iron and liquid hot metal operations.

Novolipetsk Steel is the key company within NLMK Group. The company includes all steel-making and servicing facilities. Iron ore raw materials and fluxes for sinter production are delivered from mining and concentration plants of the Group. Coke at the company and at Altai-Koks - the Group’s plant - is produced from purchased coal. In order to improve competitiveness, starting from 2013 at all production stages of the company and plants supplying raw materials and coke to it, systematic work has been performed aimed at improvement of processes according to the principles of the approved concept “Ideal technology”:
- compliance of quality and consumption of burden and process fuel with conditions of physical and chemical processes in facilities necessary for achieving required product quality;
- maximum use of design capacities of facilities;
- environmental friendliness.
As a result, within 30 months of the company’s operation coal purchasing for production of coke calculated per ton of hot metal has been reduced by more than 14%, production of hot metal, steel has increased by 10-15%, and 3-5%, respectively, production capacity of blast furnaces has grown by 15-25 %.

In this work the reaction between an equimolar synthetic zinc ferrite-ZF and Electric Arc Furnace Dusts-EAFD samples and a mixture of CO - CO2 gases were studied to evaluate the effects of temperature and CO content. The temperature ranged from 1073 to 1373K, and the gas mixtures from 50% to 100% of CO. These tests were supported by physical, chemical, structural and microscopic characterizations of both, initial zinc ferrite generated in the laboratory and the remained after reaction. It was observed that the temperature and CO content were the main factors affecting the zinc ferrite reduction. The maximum reductions of ZF indexes obtained in these experiments were 85%, for 100% CO at 1373K, in 105 min, and 52%, for 50% CO at 1373K, elapsed 105 min and 100%, for 100% CO at 1273K, in 80.75 min, and 60%, for 50% CO at 1373K during 105 minutes. The Apparent Activation Energies obtained of ZF and EAFD reduction is between 55.60 to 54.74 kJ/mol and 91 to 100 kJ/mol, for 100%CO and 50% CO-50% CO2, respectively. Values of Apparent Activation Energy-Ea estimated a predominant chemical reaction as control mechanism during the gaseous reduction of ZF and EAFD samples.

The last 10 years have been quite remarkable for the iron ore industry. The rate of increase of iron ore prices experienced before and during the world economic crisis of 2008-2009 was never seen before. On the other hand, the fast fall of the value of this same commodity in the last couple of years was also unprecedented. Seaborne iron ore market reached levels well above the most optimistic predictions made at the turn of the millennium. New projects of extremely high capacity were commissioned and several prospective new projects were in the pipeline, but many of these latter ones failed to be completed on time to get the high price scenario. The answer to the high demand was clearly the development of projects with very high capacities, high level of automation and control and optimized capital investment like modularization, quick construction and fast ramp-up. However, big projects are inherently very costly in terms of environmental licencing. Finding the compromise of short times from discovery to production caused difficulties and delayed the commissioning of some very high quality iron ore projects. With high prices, several other not so big projects, based on resources that could not be classified as world class, were also developed. Iron ores of medium to good quality derived from these medium sized projects made their way in the hunger seaborne market. These projects, based on resources with some intrinsic difficulties opened the way to increased beneficiation schemes, transforming low quality run-of –mines into acceptable and marketable iron ores. Taking into consideration the new scenario, of low prices and lower demand, the lessons learnt while developing the medium size resources should be utilized to navigate in the current market. Because of their smaller environmental footprints, smaller scale deposits with the proper application of available technology may represent the answer for the near future.

The presented work solves the problem of increasing steel quality with minimal cost by microalloying steel with boron during the formation of oxide system aI-SiO2-MgO-Al2O3-B2O3 in ladle furnace with use of the colemanite. Colemanite - boron-containing material containing B2O3 up to 40%, which is produced in Turkey.
Physico-chemical properties of the oxide system aI-SiO2-MgO-Al2O3-B2O3 (slag viscosity and interfacial distribution of boron) were researched. The rational composition of boron-containing slag and method of slag formation in the ladle furnace using lime, aluminum and colemanite were developed. Processing a low carbon steel by slags provided content of boron in the steel 0,001-0,012%, a decrease in the concentration of sulfur 0,005-0,015%, a decrease in the concentration of manganese in the metal on 0,02-0,04%, decreased consumption of manganese ferro-alloys from 0.3 to 0.6 kg/ton. New data on the morphology of nonmetallic inclusions, on the structure and on properties of the steel are obtained. Increasing the strength properties of steel and preserving the plastic characteristics are observed.

To improve the inclusion characteristics in high strength pipeline steel and further enhance its corrosion resistance in the chloride ion medium , the characteristics of inclusions in Al-Ti complex deoxidized and Ca treated steel and their effect on the corrosion behavior in the chloride ion medium was investigated, the morphology, composition, deformation and distribution of inclusions in the steels with different Al content were characterized by SEM+EDS and Image Pro-Plus 6.0, and their corrosion susceptibility was evaluated by the experiment of natural corrosion and electrochemical polarization. The results show that compared to the Al-deoxidized steels, the number density of the inclusions with ellipsoid or elongated morphology in the Ti-deoxidized steels was relatively large, the size was small and the ratio of elongated inclusions with larger deformation aspect ratio (more than 1.5) was smaller, respectively. As a result, the natural corrosion rate of Ti-deoxidized steels in the chloride ion medium for 15 days were small. Furthermore, the pitting potential of Ti-deoxidized steel in the chloride ion medium was higher than that in Al-deoxidized steels, and its electric current density was smaller, which means the pitting corrosion resistance of Ti-deoxidized steel was better. Besides, the larger the inclusion was, the larger the corrosion area of steel matrix around the inclusion was. So, the smaller corrosion susceptibility of Ti-deoxidized steel is mainly attributed to a refiner and smaller deformation aspect ratio of inclusions compared to Al-deoxidized steel.

The progressive exhaustion and rising prices of high-quality iron ore resources compel people to use in large quantities iron ores with high phosphorus contents and it is better to deliver high phosphorus hot metal to the steelmaking converter after has been pretreated for removing phosphorus. It is urgent to solve a series of techno-economical difficult problems for the dephosphorization pretreatment technology of high phosphorus hot metal, and their solutions can be summed up as the attainment of pretreatment fluxes with high dephosphorization capacity, of small consumption, being environmentally friendly and convenient for recovery and reuse through optimizing the design of dephosphorization flux contents. In this paper, the phosphorus distribution ratio between carbon-saturated hot metal and a kind of heterogeneous dephosphorization flux were measured by accepting the indirect method and several microcosmic measuring techniques were applied to the study of the presence forms of phosphorus in the heterogeneous fluxes. The results demonstrated that, for the dephosphorization of high phosphorus hot metal, the increase of solid to liquid ratio and a control of lower FeO content in the liquid slag are beneficial to the increase of phosphorus distribution ratios; the phosphorus contents in liquid slag are extremely low and it mainly presents in the solid solutions, the maximum P content in the solid solutions is 14.23 pct, and there are two kinds of phosphorus-containing phases, i.e. Ca15(PO4)2(SiO4)6 (low phosphorus phase) and Ca5(PO4)2SiO4 (high phosphorus phase), and the P content phase content is higher at a lower solid to liquid ratio.

The goal of this study is to investigate the effects of strip steel surface temperature, nozzle stretching length as well as the distance between nozzle and strip steel surface on the heat transfer property during gas jet cooling through the continuous annealing furnace process. It is observed that strip surface temperature has no effect on the convection heat transfer coefficient. Deviation emerges between the experimental results and the calculated values of Martin formula with increasing Reynolds number and reaches even about 15% when Re>60000. Regression equation coefficient C relating to nozzle box structure achieves the maximum value with H/B increasing to 8. Appropriate length reaching out can strengthen heat transfer when H/B<10. The method of calculating the convection heat transfer coefficient can be presented using Nu=CRe^0.8Pr^0.4.

Tire cord steel is widely used in vehicle radial tire skeleton. The inclusion limits in tire cord steel are strictly and many researchers have paid much attention on the removal of inclusions in steel to improve its cleanliness. In this study, the confocal laser scanning microscopy was used to in situ observe the inclusions behavior of the tire cord steel. The result shows that the capturing of inclusions into the grain interior by the solidification front depends on the cooling rate and the size of inclusions during the process of cooling. The inclusions may be captured into the grain interior if the particles size is larger than the critical diameter at a certain cooling rate. Meanwhile, it is also found that the inclusions which present earlier can be taken as a core of the growth of MnS inclusions. Both the particle size and the amount of the MnS inclusions precipitation decrease with the cooling rate increasing. The particle size of the heterogeneous nucleation inclusions depends on the initial core diameters. Within a certain range, the bigger the diameter of the core is, the smaller the size of the inclusions will be.

Improved coke and sinter quality have facilitated an intensification of the blast furnace (BF) operation due to higher gas top pressure, blast rate and blast oxygen content, as well as the flow rate of injected fuel. Specific BF productivity has increased 15-30% accompanied by a reduction in fuel rate. The increased gas intensity of melting has facilitated faster indirect wustite reduction without any negative impact on the reduction efficiency.

The ThyssenKrupp CSA Blast Furnaces have a special profile in their 3,000m³ class of volume. Their stable operation with high production and low fuel consumption depend on the ferrous materials used. In view of the current challenge in the markets of ferrous raw material due to the worsening of the quality, the development of new solutions of charge has been an important issue to keep stability and high productivity and the phenomena comprehension is the key to make the operational model suitable.
This paper presents a review of the phenomena caused by the change in the metallic charge and the consequences in the process of the TKCSA Blast furnaces as well as the phenomena due to sinter quality variation.

In this paper , the problem of the short life of blast furnaces was indicated. Then the longevity design concept of blast furnace hearth was analyzed, including structure design, refractory selection, cooling system arrangement and online monitoring system establishment. Then the longevity design concept of Chinese blast furnace hearth was analyzed and the future longevity design proposal of blast furnace hearth was put forward.

The carbide capacity of CaO–SiO2–Al2O3 slags and the iron carburization rate through consecutive phases of carbon, slag, and metal are measured at 1723 K. The carbide capacity of high-basicity slag is higher than that of simulated blast-furnace (BF) slag. The iron carburization rate through CaO–SiO2–Al2O3 slags is much smaller than the rate of direct carburization or that through slags including iron oxide. It is found that the carburization rate of iron through slags increases as slag basicity increases. The apparent rate constant of the carburization reaction, k [mol/(m2 s)], is derived as follows: k = 2.71 × 10&#8722;5 for the simulated BF slag and k = 8.00 × 10&#8722;5 for the high-basicity slag. The rate increases with increasing slag basicity, increasing carbide capacity and decreasing oxygen partial pressure.

The present work includes a kinetic study, focusing zinc ferrite’s formation from an equimolar mixture of pure iron oxide, Fe2O3 and pure zinc oxide ZnO, due to the fact that this substance is an important constituent in the steelmaking processes dusts.
The zinc ferrite that is formed during the operation of steelmaking processes, particularly the electric arc furnaces, can result from an equimolar mixture, although it could be produced from a wide range of constituents compositions. Initially, the equimolar mixture was characterized thermally (DTA -TGA) and structurally (XRD). The temperature where this compound began its formation and the quantitative results regarding the zinc ferrite synthesis conversion were calculated by the software Topas 2.1 Difracc Plus, using the Rietveld XRD method. The following experimental results from the kinetic analysis were obtained: at low-temperature range 873 - 1003 K the phenomena fitted the phase boundary reaction (spherical symmetry model) and the random nucleation (one nucleus on each particle model). The obtained data in both cases were: Ea = 272 and 275 kJ / mol., for the activated energies and 2,32 x 1013 and = 1,23 x 1015 h -1 for the frequency factor, respectively. On the other hand, at high-temperature intervals, 1023 -1273 K, the modified population growth formalism showed the best fit. Again, the obtained data was: Ea = 67 kJ / mol. and = 570 h -1.

Charcoal is an attractive material in blast furnace operation due to its high possibility of CO2 emission mitigation.
This paper describes exergy analysis of practical operation data of ironmaking blast furnaces and dynamic simulation of the blast furnaces by using a multi-dimensional CFD model. Exergy analysis provides a comparison of energy consumption and CO2 emission between practical operations of the ironmaking blast furnaces with respective coal and charcoal charging. As a result, charcoal charging can decrease CO2 emission due to global carbon circulation with plantation of eucalyptus. But lump charcoal has not enough strength for the operation of large blast furnaces thus at present lump charcoal is charged only in small size blast furnaces.
Injection of pulverized charcoal through tuyeres is another promising technology which can be applied to large blast furnaces. Dynamic simulation has been conducted by using the CFD model of blast furnace process on the practical operations of a large blast furnace with a respective injection of pulverized coal and charcoal at the rate of 200kg/thm. Simulation results showed good agreement with practical operation data.
Afterwards, mixed injection of pulverized coal ad charcoal was simulated providing slightly higher productivity in the case of the injection rate of 100kg(PC)/thm+100kg(PCH)/thm than the case of 200kg(either PC or PCH)/thm. Higher combustion rate of the pulverized charcoal than the pulverized coal contributed this results. The dynamic simulation clarifies also the changes of in-furnace phenomena which is effective information for controlling the operation.
Keywords: Charcoal, Blast furnace, Exergy, Mathematical model,

The results of studies of the properties, microstructure and nonmetallic inclusions (NI) in the pipe steel, microalloyed by boron were presented. Experienced rolled metal samples containing 0.005-0.009% boron, characterized by a low content of NI, the volume concentration of which is reduced from 0.035% to 0.016-0.025%. Phase composition NI is represented mainly by small oxysulfide and sulfide inclusions. NI size is 0-5 micrometers in experimental metal rolling and comprises 99.2-99.7% versus 80.6% in the comparative metal. The structure of boron steel is finely dispersed and is represented mainly ferritic phase with a grain of 12.0-12.5 points. Mechanical properties experienced rolled metal thickness of 10 mm tubular steel 17G1SU due to the reduction of pollution NI is represented by small, evenly distributed over the metal volume of oxide and oxysulfide inclusions, the formation of fine ferrite structure and boron present in the form of the introduction of the solution into the lattice and, of &#945;-Fe, provided the release of higher grade X80 strength.

The Brazilian steel industry uses blast furnace - BF as the main technology to produce hot metal. Currently, the blast furnace continues being the best option among the several ironmaking technologies, due to its high production rate, optimized thermal performance, operational stability and safety, as well as great longevity of the equipment performance. However, various improvements are still being researched, such as the operational control of the reactor and the reduction of its energy consumption, both aiming to prevent failures, to reduce its energy consumption and keep competitive the productivity in an international market point of view.
This work presents a model with the objective to generate a surface of minimum consumption for the major reductant (carbon) used in BF. In developing the model the equilibrium conditions, the mass and energy balances and the equations of the major operational parameters, were fully considered. Its application to the blast furnaces is exemplified for real operational conditions, using databases extracted from industrial reports of an integrated steelworks . It was also possible to obtain, from cutting plans on these surfaces, binary diagrams, of RC-DR type (Reductant Consumption-Direct Reduction), able to be generated on-line with the process. Among the results obtained from the real case studies, one was of particular interest, since it confirmed and predicted important thermodynamic unfeasibility of the furnace, called “furnace frozen”, which, additionally also provide greater operational safety to the process. The results obtained applying this model to regular and abnormal blast furnace operational condition, also led to conclude that the main objectives were fully succeeded.

The Brazilian steel industry uses blast furnace - BF as the main technology to produce hot metal. Currently, the blast furnace continues being the best option among the several ironmaking technologies, due to its high production rate, optimized thermal performance, operational stability and safety, as well as great longevity of the equipment performance. However, various improvements are still being researched, such as the operational control of the reactor and the reduction of its energy consumption, both aiming to prevent failures, to reduce its energy consumption and keep competitive the productivity in an international market point of view.
This work presents a model with the objective to generate a surface of minimum consumption for the major reductant (carbon) used in BF. In developing the model the equilibrium conditions, the mass and energy balances and the equations of the major operational parameters, were fully considered. Its application to the blast furnaces is exemplified for real operational conditions, using databases extracted from industrial reports of an integrated steelworks . It was also possible to obtain, from cutting plans on these surfaces, binary diagrams, of RC-DR type (Reductant Consumption-Direct Reduction), able to be generated on-line with the process. Among the results obtained from the real case studies, one was of particular interest, since it confirmed and predicted important thermodynamic unfeasibility of the furnace, called “furnace frozen”, which, additionally also provide greater operational safety to the process. The results obtained applying this model to regular and abnormal blast furnace operational condition, also led to conclude that the main objectives were fully succeeded.
References:
[1] APARECIDO C. WELLINGTON, Aplicação de um método de Simulação - otimização na cadeia produtiva de minérios de ferro, Master Dissertation. EPUSP, Logistic System Engineering Post Graduation. September, 2007.
[2] BILIK J.; KRET J.; BEER H.: Application of The Simulating Mathematical Models for Decreasing of The Blast Furnace Fuel Rate; available on: http://www.ams.tuke.sk/data/ams_online/1998/number1/mag07.pdf
[3] DA SILVEIRA RIZZO, ERNANDES MARCOS. Introdução aos processos Siderúrgicos. São Paulo, 2005.
[4] DA SILVEIRA RIZZO, ERNANDES MARCOS. Processo de Fabricação de ferro-gusa em Alto-Forno. ABM. São Paulo, 2009.
[5] DE AGUIAR MELGAÇO JR., HÉLIO. Aplicação dos métodos gráficos de Rist e Reichard no controle operacional de Altos Fornos a coque. Master Dissertation. PUC-RIO, Metallurgical Engineering Post-Graduation (Advisor: José Carlos D’ABREU). September, 1985.
[6] DE ARAÚJO, L.A. Manual de siderurgia. 1° volume. São Paulo: Editora Arte & Ciência, 1997.
[7] DE CASTRO, L.A., Desenvolvimento De Um Modelo de Controle de Processo Para Altos-Fornos A Carvão Vegetal, Doctoral These. UFMG, Metallurgical and Mines Engineering Post-Graduation. August, 2002.
[8] DE MELO WILSON ROBERTO, Controle do processo de Redução no Alto-Forno II da Cosipa aplicação do diagrama CRRD. Master Dissertation. PUC-Rio, Metallurgical Engineering Post-Graduation (Advisor: José Carlos D’ABREU). February, 1987.
[9] FUMITADA NAKATANI, T. MUKAI, F. NAKAMURA, Theoretical Consideration on Coke Ratio of the Blast Furnace Operation, Steel Science Portal. November, 1965.
[10] DIONISIO CALDERON, ENRIQUE R., Superfície de Mínimo Consumo de Carbono do Processo de Redução em Altos-Fornos. Doctoral These, PUC-Rio, Chemical and Materials Engineering Department (Advisor: José Carlos D’ABREU). February, 2016.

The high levels of phosphorus demand operations of dephosphorization for steel manufacturing steps resulting in high costs. One way to minimize these costs is the removal of phosphorus in the iron ore particles using the acid leaching process; however, depending on how the phosphorus is complexed in the mineral phase requires the application of additional energy. However, when the phosphorus removal process using acid leaching also occur in the ore particles loss of iron and leaching aluminum. The loss of iron is undesirable for the beneficiation process while aluminum is beneficial for the efficiency of the concentration and has a positive effect on the subsequent step of reduction. Currently, there is no viable technology for simultaneous removal of phosphorus and aluminum in iron ore. Understanding the mode of occurrence of these elements in minerals will surely bring new information that eventually may subsidize the development of methods for their removal. In this work, we propose, a model to predict the effects of addition of energy in the iron ore particles using microwave energy due to its efficiency in heat generation. Therefore, in this study, we evaluated the acid leaching process in the iron ore particles targeting of reducing the phosphorus and aluminum contents and was also evaluated the removal of iron in the particles. Through factorial statistical design technique with central and axial points, we determine the optimum conditions employed in the acid leaching process. The following values for experimental optimum conditions were: 19,25g mass of ore, leaching time 20 min, temperature 650C leaching, agitation speed of 620rpm, average particle size of 595 microns, having a 3-minute contact time with the power of microwave. Under these conditions, the reduction of phosphorus content in iron ore sample reached a value of 52.47%

Steel slag may be an alternative as cement mineral admixture, partially substituting the BF slag. A pyrometallurgical process has been investigated to promote the chemical composition modification of molten steelmaking slag in slag pot. Experiments were carried out by remelting 300 kg of steel slag followed by chemical modification of liquid slag. The modified slags were naturally cooled in the slag pot or cooled by steel balls. XRD and SEM analysis of slag samples showed a relationship among chemical composition, cooling condition and amorphous and crystalline phases. Cement samples were produced by mixing 25% of treated steelmaking slag with 75% of Portland cement, resulting in more than 280 J/g of accumulated hydration heat in 72 h, expansion lower than 0,5 mm and compressive strength higher than 28 MPa and 35 MPa after 1 and 7 days, respectively. The process shows potential to be applied as a steelmaking slag treatment.

A numerical model based on transport equations of momentum, energy and chemical species for the gas and solid phases is proposed to simulate the inner phenomena in the direct reduction of the shaft furnace process for producing directly reduced iron (DRI). The model is verified using industrial data for productivity, raw materials and final composition of the DRI product. The model is used to evaluate operational practices using new raw materials and the composition of the reducing gas in the process. Three cases were considered, which correspond to available raw materials commercialized by different suppliers. The effects of the gas and solid inner temperatures, pressure and phases compositions distributions are quantified. The simulation results indicated that good agreement for overall parameters of the process could be achieved and afterwards, detailed features of the inner conditions of the process are predicted.

During quenching process of steel plate, control parameters are important to production quality. In this work, a thermal process mathematical model has been developed for roller-type quenching machine to predict the temperature field of a plate at first, and then an optimization schedule considering quenching technology and equipment limitations was presented to obtain the best roller velocity based on it. A numerical simulation has been performed during optimization process to investigate the effects of roller velocity to the temperature of the representative plate. Taking the optimization method, a study was also performed for different thickness of the plate to obtain the corresponding roller velocity. The results show that the optimized roller velocity can be achieved on roller-type continuous quenching machine by the optimization method based on the thermal process mathematical model.

One of the main steps in the characterization of iron ore pellets is the quantification of porosity. Traditionally it is measured by mercury intrusion porosimetry (porHg) - that only reveals open pores - and/or optical microscopy (OM) - that only provides 2D information. Both processes are destructive and require expensive and/or toxic consumables, with direct impact on the environment after disposal.
X-ray microtomography (microCT) is a promising alternative. It is non-destructive, requires no specimen preparation, can analyze full pellets and provides 3D information of total, open and closed porosity. The main drawbacks of the technique are its limited resolution (approx. 2 to 4 µm when scanning a full 12 mm diameter pellet) and the acquisition and processing time (approximately several hours per pellet).
This paper describes the development of the 3D methodology to measure the porosity of iron ore samples. It involves optimization of image acquisition parameters, a sequence of automatic 3D image processing and analysis steps, 3D visualization, and comparison with porHg and OM.
Employing a Carl Zeiss Versa 510 x-ray microscope, pellets were scanned with different resolutions to evaluate the impact on the measured pore distribution. Noise filtering, edge enhancement and careful manual thresholding were used to segment pores. Initial tests with 8 µm resolution, which allows visualization of a full pellet, showed that the main porosity peak revealed by porHg (approx. at 10 µm) is not detected. The second set of experiments exploiting the geometric flexibility of source-sample-detector setup reached 4 µm resolution, albeit with the loss of a small peripheral layer of the pellets. In this case, the main porosity peak is detected. The numerical results, however, are still very different from porHg.
To compare with OM, after microCT the pellet was cut in a plane orthogonal to the microCT rotation axis, then mounted and polished. Computer controlled OM was used to create a mosaic image covering the full cross section with 0.53 µm resolution. The acquired image was used in an automatic correlation procedure to detect the closest microCT layer image. Due to specimen preparation errors, the OM image is not perfectly parallel to this closest MicroCT layer. Thus, the OM image was automatically registered to the microCT image. Finally, the porosity values were compared. As expected, the porosity measured by OM was much larger than the value obtained from microCT.
Each of the techniques has its own limitations, with microCT providing true 3D information in a non-destructive sequence that requires no specimen preparation. Further quantitative comparison is expected to provide a road map to correlate the values obtained from the different techniques. In principle, this can allow microCT to become the main technique for measuring porosity in iron ore pellets.
Practical application of this methodology will also require a substantial reduction in microCT scanning and processing time. New methods such as DART – Discrete Algebraic Reconstruction Tomography – are currently under development, in order to reduce the required number of image projections while preserving the pore segmentation quality.

In order to investigate the dust formation mechanisms via gas bubbles bursting at the surface of the metallurgical melt, water model experiments on a single bubble in the water/oil solution were performed. Different parameters, such as gas blowing time and volume, the height of collecting device and slag viscosity, on the bursting liquid drops (dust) output and the change of physical properties such as bubble shape were considered. The results show that the bubble size increases with the increase of the diameter of the bottom-blowing pore, the bubble continuous overturn when it goes up and its movement becomes more tempestuously with the increase of gas bubble size. The bursting droplet generation increases with blowing time. With the increasing of gas volume, the ascending of gas bubbles will accelerate and gradually increase the received splashing droplets content. The collected droplets reduce with the height increase of collection device. When the height of collection device is more than 12mm, the collected bursting droplets almost keep constant. Moreover, the slag (oil) viscosity improvement is detrimental to the droplet generation.

Many experiments related to investigate the properties of higher alumina slag had been carried out through adjustments of slag composition and test temperature. The influence of MgO and basicity (CaO/SiO2) on melting temperature and high temperature(1400-1500 ¡æ) viscosity was especially paid attention. The experimental results show that when Al2O3 range in 15-16.5%, MgO range in 7-7.5% and basicity range in 1.2-1.3, the BF slag display typical properties of short slag, and can perfectly satisfy the requirements of blast furnace operations. Meanwhile, the melting temperature of serpentine is higher and can not drip, which is always used as a flux adjusting the slag component Meisteel. A higher softening and melting temperature will result in a thicker cohesive zone and have the negative effect on the smooth process of BF. Thus, the industrial trial of using higher alumina slag (>16%) had been implemented at No.5 BF (inner volume 4000m3) in Meishan steel based on the experimental results. As a result, the addition of serpentine flux was stopped, the blast furnace maintained smooth and steady performances, the productivity maintained 2.2t/m3.d, and the fuel rate was decreased 3kg/t, with the BF burden quality degradation.
Keywords: Blast furnace, Slag, High aluminum, Ironmaking

The test results showed that the yield, tumbler index and productivity of sinter when the project of oxygen enrichment was carried out were increased and the fuel cost was decreased. Due to the higher oxygen content in the air, the condition of the fuel combustion was improved and the combustion efficiency was increased. Sintering with oxygen enrichment would help to increase sintering production, stabilize BF (Blast Furnace) operation, reduce coke cost and boost the production of BF. Besides, the off-gas emission should be an additional benefit.

Currently the production and use of DRI are increasing in developed countries, mainly due to the reduced price of natural gas and the success of the new shale gas extraction technology. In addition, the lower level of DRI contaminants than in scraps, led the former to be considered a good alternative as a metallic burden for Electric Arc Furnace (EAF) and LD / BOF converters.
Operating costs and environmental problems are actually important technological factors to be considered in the optimization of DRI production. Therefore, the carbon content of DRI has become one of that, due to the ability to generate chemical energy in steel bath, thus complementing the electricity in EAFs, and the exothermic contributions of Si and C oxidation in the LD.
This work is part of a whole cooperation program between Samarco Mining Company and the Iron & Steelmaking Research Group of the Pontifical Catholic University of Rio de Janeiro / PUC-Rio, dealing with the kinetic equations for the simultaneous metallization and carburization in DR shaft furnaces. For this purpose, the reactor was divided into three internal zones: Reduction, Transition and Cooling zones. Additionally, were also considered three concentric regions: peripheral, media and center. Using the results for a specific RD pellet, gas mixtures used in the industrial plants and fluid dynamic similarities of the process, the metallization and carburization kinetic equations were established for each zone. A computational program-METCARB, fully based on those kinetic equations, was then conceived. Finally, the further validation was proceeded taking into account two industrial operational runs.

Laboratory researchers and mathematical modeling of the physicochemical and thermophysical processes, carried out in Institute of Metallurgy, have for an object establishment of the formation mechanism of metallurgical properties of agglomerate and pellets at oxidizing roasting and an estimation of influence of metallurgical properties (reducibility, durability, softening and melting temperatures) on processes heat and mass exchange at the reduction in the blast furnace. At the same time, the principal reserve of decrease of the coke consumption and improvement of technical and economic indicators of blast furnace smelting is an improvement of the quality of iron ore raw materials. A new method for the estimation of the influence of the iron ore materials metallurgical properties on the efficiency of blast furnace smelting is developed. It consists of the following stages: the laboratory tests with the definition of the iron ore materials metallurgical properties; the analytical study of the influence of these characteristics on the efficiency of blast furnace smelting using mathematical models; the experimental industrial and industrial tests. Examples of an assessment of metallurgical properties of agglomerate and pellets from a titanomagnetite concentrate and results of calculation of indices of blast furnace smelting are given.
As Keynote Paper

Steel industry produces a large number of V-bearing converter slag, the slag with relatively high vanadium content is an important resource of vanadium, on the other hand, if it is not properly handled, which will cause heavy metal pollution. At present, the method of wet extraction vanadium is not suitable for V-bearing converter slag with relatively low grade of vanadium, it is necessar to enhance the grade of vanadium by mineral processing before leaching, while the vanadium in the slag dispersely distribute, the concentration effect of ore dressing is poor. Vanadium concentrating in one or two ore phases need to be conducted before mineral processing. Taking into account the following separation vanadium, iron spinel phase has big property difference from main phase in converter slag, which is a suitable choice for vanadium enrichment phase. Based on this, the formation of vanadium iron spinel phase in converter slag modified will be invesigated through experimental and theoretical calculation under reducing conditions in this paper. The research results show that the vanadium content in concentrating phase is more than 12%, meeting the requirement of vanadium grade of hydrometallurgical vanadium recycling.

By using the method of the thermal simulation experiments and energy spectrum analysis, this paper has studied the influence of the cooling rates and the initial temperature of liquid steel on full equiaxed crystallization behavior in solidification of 40Cr steel strand. The results show that the full equiaxed grain can be gained when the proper cooling rate was adopted, when the cooling rate in the surface of corundum crucible is increased from 3.83 oC/min to 8.6 oC/min, the average grain size of solidification structure is decreased from 8.76 mm2 to 2.01 mm2, and the distribution of chromium elements in the half height cross-section of specimen is uniform, the maximum difference of microsegregation rate is decreased from 0.274to 0.181. With the initial temperature of liquid steel increasing, the average grain size of 40Cr steel increases, when the initial temperature of liquid steel is increased from 1496¡æ to 1508¡æ, the average grain size of solidification structure is increased from 2.01 mm2 to 5.10 mm2, the influence of the initial temperature of liquid steel on the microsegregation of chromium is not significant. These results may provide some experimental basis for the analysis of the solidification behavior and influence factors in the central region of the continuous casting for chromium steel.

Converter steel slag is a by-product of the processing from iron to steel, more than 100 million tons were produced in China every year. Reusing these slags as a recycled material can be regarded as a way to reduce environmental pollution and consumption of natural materials. However, the poor grindability caused by complex chemical composition and microstructure of converter steel slag makes it very difficult to be recycled. Converter steel slag contains 30-60% polymorph dicalcium silicate (C2S), whose crystal structure can be changed from ¦A-C2S to ¦A-C2S at the certain temperature, accompanied by 11% volume expansion, which could result in self-pulverization of steel slag. In the research, the influencing factors on steel slag self-pulverization were studied using XRD spectral fitting refinement method and thermodynamic equilibrium calculations. The P content in steel slag has a remarkable effect on steel slag self-pulverization, the carbothermal reduction has been introduced to reduce the effect of P on self-pulverization. The results provide a theoretical basis and composition conditions for grindability improvement of steel slag and expand its utilization.

It is a vital measure of energy-saving and emission reduction for iron and steel industry that limestone is used instead of active lime in converter steelmaking process. The effect of the microstructure on the reactivity and physico-chemical properties of lime were investigated. The limestone (12.5-15mm) was calcined fastly at 1450¡aC for 5min to 15min. The results show that the escape of CO2 promotes highly developed micropores forming after calcining at 1450¡aC for 5min to 10min. With the extension of calcining time, CaO recrystallizes and grows up, resulting in the disappearance of micro pores and densification for the structure of lime. With regard to the physic-chemical properties, the porosity of lime quickly increases at first and then decreases, which reaches the maximum at 10min, with the extension of calcining time. However, the variation of bulk density is opposite. The specific surface area of lime decreases with the extension of calcining time. The reactivity of lime reaches the maximum when calcined for 10min. In the condition of high temperature and fast calcination, CaCO3 decomposition is from the outside to the inside. CaO grain on the surface of lime has recrystallized, grown up and become dense, but CaCO3 is still in the decomposition inside of lime, leaving a lot of micro pores.

The Ni-TiO2/TiO2 multilayer which was composed of TiO2 and Ni-TiO2 monolayers was fabricated by the pulse electrodeposition technique. The nanostructured composite was annealed at 450°C for 3 hours, and the surface and cross-sectional morphologies of the coating were characterized using scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM). Hydrophilicity and wettability of the multilayer were investigated under UV illumination and the water contact angle was measured. Surface hydroxyl groups density which accounts for the photoinduced hydrophilicity of the coating was defined by X-ray photoelectron spectroscopy (XPS), before and after UV illumination. The results indicated that in the optimized condition, the water contact angle of the coating reduced to 7.23° after 1 hour of UV irradiation and a 16% increase was detected in the density of hydroxyl groups. The photocatalytic activity of the coating was characterized by the degradation test of methyl orange and it was confirmed that TiO2 content, irradiation duration and sintering temperature affect the photocatalytic efficiency of the coating and the multilayer was capable of disintegrating the methyl orange up to 53.64% after 5 hours of UV illumination. The photoelectrocatalytic degradation of methyl orange using Ni-TiO2/TiO2 multilayer coating was studied and the effect of different applied potentials was determined. The amount of methyl orange degraded by multilayer under the anodic potential of 600 mV along with 2 hours of simultaneous UV illumination was 97.22%.

Waste slag is a major source of environmental pollution within the metallurgical industry. In the steel industry, about 100-150 kg of waste slag is produced in making one tonne of liquid steel from iron in addition to that produced during ironmaking. The amount of waste slag from the steelmaking converter can be significantly reduced when charging hot metal with low phosphorus and sulphur contents. There is a great interest in searching for fluxes for hot metal pre-treatment and liquid steel refining which produce high efficiency, low cost and environmentally friendly processes. In the aluminium industry, about 2-4 tonnes of waste slag, including by-products (red mud and white mud) from alumina production and dross from aluminum electrolysis and casting, are generated during the production of one tonne of aluminum. Red mud is the by-product from alumina production and it is the largest environmental concern of alumina refineries mainly because of the size of this waste stream and its causticity.
In this context, the research carried out at the University of Toronto associated with the reuse of waste materials or by-products from the aluminum industry as refining fluxes in the steel industry will be summarized. Topics discussed include: (1) Reuse of white mud generated during aluminum melting and refining for hot metal desulphurization; (2) Using fluxes produced from red mud for hot metal simultaneous dephosphorization and desulphurization, and (3) Removal of phosphorus, sulphur and arsenic from nickel-based alloy generated during the treatment of used catalysts from the petroleum industry. Promising results were achieved in each of these research areas. Sustainable processing of waste materials or by-products from one industrial sector can provide economical refining materials for other industrial sectors and generate environmental and social benefits for both sectors.

The vibrating electrode in the ESR process as an innovative technology has been proposed. The relative movement between an electrode and molten slag can be effectively performed by vibrating electrode, which will accelerate the melting rate significantly. It can reduce the energy consumption and improve the quality of solidification. Therefore, it is necessary to explore the characteristics of multi-physical fields, especially to understand the effect of dominant parameters, such as ratio and slag thickness, on the vibrating electrode electroslag remelting process. The main purpose of this paper is to explore the rules of the effect of ratio and slag thickness on the multi-physics fields, which will provide theoretical guidance for practice production in the electroslag remelting process of vibrating electrode.

The mathematical model of thermal processes in a hearth laying of the blast furnace allows on the basis of temperatures data in the fixed points of a laying is developed to determine a temperature field on height and radius of fireproof lining and on the basis of the received information to define a furnace hearth profile. The developed mathematical model is realized in the software introduced in the operating metallurgical units for an assessment of a condition of fireproof lining of a blast furnace hearth. Introduction is carried out in five blast furnaces in the People's Republic of China with registration of the relevant acts. Due to universality of the developed mathematical model its software can be introduced in blast furnaces where other models of creation of a fireproof lining wear on the basis of indications of temperature sensors in a laying as the main or duplicating system are already used. In particular, the model was used for an assessment of a condition of a blast furnace No. 5 of Nizhniy Tagil Iron and Steel Works. As a Keynote Paper.

Within the thermodynamically possible experiment condition, the oxidation performance experiments of the powdery and blocky carbon brick were conducted in air at the temperature of 800¡æ, 1000¡æ and 1200¡æ to study their oxidation behavior and oxidation kinetics in both non-isothermal and isothermal condition. The results showed that, in terms of the non-isothermal experiment, the weight loss of carbon brick and the rate of oxidation reaction were small below 500¡æ. However, the rate of oxidation reaction increased after temperature over 500¡æ. The relationship between weight loss and temperature was approximate linearity with the fitting equation of y=121.78+0.92(T-500), and the correlation coefficient of R2=0.9978. In terms of the isothermal experiments, the weight loss rate of both powdery and powdery cylindrical carbon brick increased with increasing temperature, indicating that the rate-controlling step was an interfacial reaction, while the weight loss rate of blocky carbon brick was unaffected by temperature, indicating that rate-controlling step was diffusion. At the same temperature, the rate data comparison of oxidation reaction between three samples was Vpowder>Vcylindrical>Vblock. Relatively speaking, due to the fastest rate of powder, once the carbon brick in the blast furnace is pulverized, the erosion will speed up significantly, thus declining its original strength.

With the aim of improving the process efficiency of FINEX technology, a thermodynamic optimization was suggested in this paper. By the two-stage fluidized CO reduction experiments of iron ore fines, the relationship between the previous stage and the followed stage were investigated. The results show that the reduction degree of the followed stage firstly increased and then decreased with increasing the temperature of the previous stage. This indicates that the reduction degree of the followed stage is strongly depending on the reduction temperature of the previous stage. Thus, the thermodynamic analysis of the iron ore reduction was carried out to clarify the optimization principle. Based on this, a high reduction degree with low energy consumption was finally achieved.

The electric arc furnace for steel making presents many challenges from the optimization stand point. There are many variables which are not possible to measure and have an important effect on the outcome of the process in terms of quality, productivity and cost. The paper describes some of these challenges and the real time optimization solutions implemented with the Visual KB software, which is an open code, online programming supervisory control system with some artificial intelligence tools developed by AMI GE international.

During the blowing out stage of Xianggang NO.1 Blast furnace, the breakage investigation was carried out by focusing on the wear mechanism of hearth carbon bricks and bottom ceramic pad as well as the formation mechanism of the embrittlement layer. By means of Scanning Electron Microscope (SEM) -Energy Disperse Spectroscopy (EDS), X-Ray Diffraction (XRD), chemical analysis, etc., the microstructure, phase composition and content of harmful elements of carbon brick samples were analyzed. The results show that the erosion of hearth sidewall carbon bricks was mainly induced by zinc, alkali, and hot metal, while the formation of embrittlement layer was relevant to the thermal stress, hot metal, harmful elements, etc. The foreign materials, like hot metal and harmful elements, resulted in the embrittlement layer by entering into the cracks that formed by thermal stress. The bottom ceramic pad was eroded by hot metal. Furthermore, TiN0.96 was found between a ceramic pad and bottom carbon brick.

Zinc is a metal of significant technological importance and its production from secondary sources has motivated the development of alternative processes, such as those dedicated to the recovery of electrical arc furnace (EAF) dust by carbon. At present, the extraction of zinc from the mentioned residue using a carbon content reducing agent is being established technically in large scale. In the present work, an alternative hydrogen reduction of a synthetic oxide mixture with EAF dust analogous composition was thermodynamically and kinetically investigated. The results confirm that the reduction process is viable for temperatures higher than 1123 K with all zinc metal being transferred to the gas stream, favoring its complete separation from iron. The same reaction in the presence of zinc crystals, aiming to hinder Zn volatilization by increasing this metal partial pressure, was considered for synthesizing FeZn alloy, but with little success. However, the possibility of reducing zinc selectively from an EAF dust sample through a H2 constant flux in a horizontal furnace was observed and zinc metal was collected in a “cold-finger” condenser adapted at one end of the furnace inner ceramic tube.

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