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This study investigated concentrations of PM2.5, PM10, SO2, NO2, CO and O3, and air quality index (AQI) values across 368 cities in mainland China during 2015–2018. The study further examined relationships of air pollution status with local industrial capacities and vehicle possessions. Strong correlations were found between industrial capacities (coal, pig iron, crude steel and rolled steel) and air pollution levels. Although statistical and significant reductions of PM2.5, PM10, SO2, NO2, CO and AQI values were observed in response to various laws and regulations in industrial sectors, both particle and gaseous pollutants still had annual average concentrations above recommended limits. In order to further reduce air pollution, more efforts can be done to control traffic emissions caused by minicars and heavy trucks, which was revealed after investigating 16 vehicle types. This was also consistent with the apparent air quality improvement during the COVID-19 lockdown period in China in 2020, despite industrial operations being still active at full capacities.

Jarosite sludge coming from the hydrometallurgical zinc production route is a hazardous material, which is currently neutralized and landfilled by the so-called Jarofix® process. The present study aims to assess the mechanical and metallurgical properties of briquettes made of jarosite powder with blast furnace sludges, acting as a reductant material, to recover the iron oxide in the form of pig iron and produce an inert slag, increasing the recovery of materials considered as wastes nowadays. Starch was used as a binder (0, 5, 10 wt%), and two different briquetting pressure levels were used (20 and 40 MPa). The results show that briquetting without a binder is not desirable, as the agglomerating forces provided by pressure only are not sufficient, as the briquettes are very fragile and not handy. The binder addition increased noticeably the briquettes resistance, however, only little distinction between the 5 and 10 wt% levels were seen. The briquetting pressure, on the other hand, showed a bigger role on the cold mechanical properties of the bound briquettes. The briquettes pressed at 40 MPa reached an average compressive strength higher than 12 MPa and good abrasion and drop resistance were seen, also showing that their production with starch as a binder is feasible. A special remark is done regarding the roasting treatment of the jarosite powder before the briquetting process, as an undesirable compound (thenardite) was formed within some briquettes due to a non-uniform heating of the powder, which hindered the briquettes mechanical properties. Metallurgical properties open the possibility to use such briquettes for iron production in cupola furnaces. Graphical Abstract

The effectiveness of high phosphorus pig iron (1.5 wt% P, 3.5 wt% P, and 8.0 wt% P) as sacrificial anode for the cathodic protection of mild steel was investigated in simulated concrete pore solution and concrete mortar. Electrochemical tests were carried out in both chloride-free and chloride-contaminated pore solution under freely aerated and deaerated environments. Linear and dynamic polarization, electrochemical impedance spectroscopy and zero resistance ammeter tests were performed to compare the electrochemical behavior of the pig iron samples to the mild steel. Laboratory and field tests were also conducted by galvanically coupling the mild steel to the pig iron samples in the concrete mortar and monitoring the polarization shift. The polarization results indicate that all three different pig iron samples show more active potential as compared to the mild steel in both chloride-free and chloride contaminated pore solutions. The open circuit potential and polarization resistance for all the pig iron samples decrease with an increase in the P content. The more active galvanic potential and positive galvanic current density for the pig iron and the mild steel couple show the effectiveness of the pig iron as a sacrificial anode in simulated concrete pore solution. The laboratory and field studies also suggest that the 100 mV polarization shift criterion has been established, and the pig iron samples are effective in preventing the corrosion of the mild steel in concrete. The first time use of iron based sacrificial anode for the cathodic protection of reinforcing steel embedded in concrete defines the novelty of the present work.

A comprehensive mathematical model is developed and tested to assess how the ore/coke ratio as a function of radius in the blast furnace affects the shape of the softening and melting (cohesion) zone. The height of the cohesion zone is determined by the temperature difference between the onset and end of melting for the iron ore materials. The cohesion zone is located between the isotherms formed by lines connecting the points corresponding to the onset and end of melting for materials in six vertical ring zones defined within the blast furnace. The location of the isotherms in the furnace space describes the configuration of the cohesion zone, which has a significant effect on the distribution of gas flow and the economic performance of the blast furnace process. A Λ-shaped cohesion zone was found to be better than a W-shaped cohesion zone from the standpoint of ensuring even operation of the furnace and improving the economic performance of the blast furnace process; however, the hearth temperature in each of the vertical ring zones must exceed the temperature for complete fluidization of the pig iron and slag by at least 50°C.

The effect of nickel oxide additive on the smelting behaviors of chromium-bearing vanadium titanomagnetite pellets (CVTP) was investigated while analyzing the transfer behavior of nickel in iron and slag. The results show that when NiO added to CVTP increases from 0 to 6 wt.%, softening start temperature increases from 1148 to 1212 °C, and the softening end temperature increases from 1280 to 1334 °C; the melting start temperature increases from 1318 to 1377 °C, and the dripping temperature decreases from 1558 to 1521 °C. The pig iron comprises a compound of Fe–Ni–C. The slag structure depolymerizes with increasing nickel addition. The softening-melting behaviors of CVTP, the reduction of nickel into pig iron, and the depolymerization of slag structure indicate the feasibility of producing nickel–iron alloy through the blast furnace process.

Pig iron, the source for a variety of iron-based products, is traded in commodity markets. Therefore, enhanced productivity has significant economic implications for the producers. Pig iron is mainly produced inside of tall, vertical, thermodynamic reactors called blast furnaces that run 24 hours a day. The blast furnaces are too complex to model explicitly and are generally regarded as black boxes. In this study, we design, develop, and deploy novel machine learning models on a rich data sample covering more than 20 production variables spanning nine years of actual operational period, collected at one of the largest pig iron production plants in Brazil. We show that, given the blast furnace parameters, machine learning models are capable of unveiling novel insights by illuminating the black box and successfully predicting production levels at different configurations. These prediction models can be used as decision aids to improve production efficiencies. We also perform a sensitivity analysis of the trained models to identify and rank the input variables according to their relative importance. We present our findings, which are largely in line with the existing literature, and confirm their validity, practicality, and usefulness through consultations with subject matter experts.

This study discusses the smelting behaviors of chromium-bearing vanadium titanomagnetite pellets (CVTP) with TiO2 additions. The results show that the softening start temperature T10% increases from 1148°C to 1215°C, and the softening end temperature T40% increases from 1280°C to 1336°C. The melting start temperature TS increases from 1318°C to 1352°C and the dripping temperature TD decreases from 1558°C to 1505°C. The primary phases of slag are (Ti0.7V0.3)2O3, (Mg0.6Ti2.4)O5, MgSiO3, and MgTi2O5, and the equilibrium phases calculated by FactSage 7.0 verify the primary phases. The titanium-vanadium compound as an intermediate reactant is generated at the interface of pig iron and slag. The FT-IR results show the depolymerization of slag, which results in the improvement of the softening–melting behaviors.

The urgent problem regarding the depletion of mineral resources in ferrous metallurgy can be efficiently solved by a complex reuse of man-caused waste products. Such wastes are mostly presented by electric arc furnace (EAF) slag and ladle furnace (LF) slag. These two kinds of slag are not completely utilized. The residues of these slags are stored in dumps of enterprises and thereby pollute the environment. However, the residues of EAF and LF slags can be converted into valuable industrial products by interaction between the slag components. This paper presents the studies concerning joint wasteless processing of EAF and LF slags with the obtaining of Portland cement clinker and pig iron. Description of the disadvantages of industrial methods for processing these slags is considered, and the relevance of ladle slag processing is shown. The mathematical simulation results of slag fluidity, depending on the composition, are presented, which are based on real investigations, as well as its described experimental technique. The chemical composition of the charge mixtures making it possible to process these slags with limestone roasting wastes into complete extent with no residue has been determined. Such processing provides the quality of produced cast iron and Portland cement clinker to meet the requirements of normative documents. Results for measuring the viscosity of different slag compositions, a description of the obtained slag phases, as well as its final temperature mode, are presented. The results of experimental-industrial tests performed for the developed processing technology are considered, and complete flow chart involving the use of tilt rotary furnaces is presented.

The purpose of the study was to conformity of the quality of coke used in the blast-furnace shop of JSC “Ural Steel” meets the requirements recommended in the scientific literature, and to study its impact on the consumption of coke and the production of pig iron at the enterprise. For the study, the blast furnace № 1 with a useful volume of 1007 m3 and the blast furnace No. 4 with a useful volume of 2002 m3 were selected. The results of the analysis of data on the quality of coke over a three-year period: ash content, volatile matter and sulphur in the coke, the moisture content in the coke, the coke uniformity coefficient, indicators of the cold strength of coke (M25 and M10), indicators of coke hot strength (CSR) and reactivity of coke after high-temperature interaction with CO2 (CRI). Studies have revealed significant instability of the moisture content in the coke, which affects the change in its consumption, and heterogeneity of the granulometric composition of the coke, increasing the stability and uniformity of which would favorably affect the indicators of the blast furnace process. It was found that the values of the indicators of M10 coke attrition, hot strength of coke (CSR) and reactivity of coke (CRI) do not meet the recommendations of domestic and foreign scientists. Measures are proposed to improve the quality of coke, the implementation of which will increase the productivity of blast furnaces and reduce the consumption of coke per ton of pig iron.

Industrialization for economic growth is harming our environment with various gas emissions, wastewater, harmful dust, and solid waste. Solid waste with hazardous content is one of the main contributors to environmental illness. The chloride media leaching of iron from high-quality ilmenite (FeTiO3) produces TiO2 pigments and chlorinated iron oxide waste (CIOW) in solid form. Direct processing of CIOW is prone to flue-losses due to its fine particle nature (35– $75~\mu \text{m}$ ). Transportation of this waste can cause air pollution. A new methodology to treat the CIOW is defined in this article. The fine CIOW is beneficiated into pellets and smelted in an ecofriendly thermal plasma setup to yield marketable low sulfur pig iron and easy disposal (chloride-free) slag. Thermal plasma provides high temperature, high energy flux, and ionized-state condition to remove/destroy the toxic nature of CIOW. The impurity analysis of the CIOW shows that it contains 2.28%Cl, whereas the final slag after the process contains 0.007%Cl. The waste processing and recovery details are discussed in detail with appropriate characterization techniques such as chemical analysis, thermogravimetric and differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM).

One of the ways to increase the energy efficiency and intensity of blast furnace smelting, especially when using pulverized coal fuel, is to increase the hot strength of coke. In the conditions of OJSC NLMK, an oil additive was introduced into the coal charge to improve the coke quality. At the same time, sulfur content in the coke increases, and, consequently, sulfur content in the cast iron increases as well. In this regard, the task of finding ways to improve the desulfurization of cast iron in blast furnace becomes urgent. The main factors determining the desulfurization of cast iron are slag basicity, content of MgO oxide in it, temperature of the smelting products, and the slag viscosity. The purpose of this work was to compare the efficiency of sulfur removal by increasing the slag basicity and MgO content. On the basis of well-known equations, an algorithm was developed that allows the problem to be solved. It was established that an increase in MgO content in the slag promotes desulfurization of cast iron to a greater extent than a basicity increase. In addition, an increase in MgO content by 1 % is accompanied by an increase in slag yield by 3.0 – 3.5 kg/t of cast iron. At the same time, an increase in basicity by 0.01 leads to an increase in the slag yield by 4 – 5 kg/t of pig iron. Consequently, reducing the sulfur content in pig iron by increasing the slag basicity requires less heat. In terms of the specific consumption of coke, difference in heat demand is 0.4 – 0.5 kg/t of pig iron. It is shown that with an increase in MgO content in the slag, the slag viscosity at a temperature of 1450 °C increases to a lesser extent than with an increase in basicity. © 2020 National University of Science and Technology MISIS. All rights reserved.

This paper is a case study of cast iron industry, which brings out the critical parameters that must be considered to reduce the burning/melting loss. The melting loss has been analyzed based on the different inputs to the induction furnace and the output as the molten metal. The various input parameters considered are boring material, briquettes, runners, steel, heel metal, pig iron, rejected/defect product etc. whereas the output is the weight of the molten metal. A detailed analysis show that the components such as boring material, scrap and pig iron in the charge increases the melting loss, while the additions such as runners, heel metal and coke reduce the melting losses. Based on the findings an empirical relation was derived to predict the burning losses during ductile iron melting which accordingly calculates the required amount of reduction agents such as coke to keep the melting loss within the limit.

The present study concentrates on investigation of the possibilities of making high basicity reduced iron ore pellets (DRI) at low cost, which can be further used in the pig iron refining or steel making technology in EAF/LD Converter process. The reduction behaviour of high flux (basicity 2, 4, 6 & 8) hardened iron ore pellets, reduced at temperature (900–1050 °C) were examined and reported here. Result showed temperature and basicity both influenced the reduction behaviour of iron ore pellets. Evolution or dissolution of different phases during reduction studied with the help of XRD and SEM.

—: With an approach to improve the strength performance and rate of blast-furnace smelting, especially when pulverized coal fuel is involved, the improvement of the hot coke strength has been considered. A crude oil additive is introduced into the coal charge in PJSC Novolipetsk steel mill (NLMK) to improve the quality of coke. This brings about an increase in coke sulfur resulting in the sulfur content growth in pig iron. Therefore, the task of finding ways to improve pig iron desulfurization in the blast furnace becomes important. The following are key factors that affect the pig iron desulfurization rate: slag basicity, the content of MgO oxide in the slag, the temperature of smelting products, and the slag viscosity. The purpose of this work deals with comparing the desulfurization efficiency through the improvement of the slag basicity and increasing the MgO content. An algorithm is developed based on known equations in order to achieve this goal. The increase of MgO content in the slag provides better input into pig iron desulfurization than the increase in slag basicity. In addition, an increase in MgO content by 1% results in growing slag to pig iron ratio amounting to 3.0 to 3.5 kg/MT. At the same time, an increase in basicity by 0.01 leads to an increase in the slag to pig iron ratio 4 to 5 kg/MT. Consequently, reducing the sulfur content in pig iron by controlling the slag basicity is less heat intensive. Recalculating to the reduced coke consumption rate, the difference in heat demand amounts to 0.4 to 0.5 kg/MT of pig iron. It is shown that the slag viscosity increases to a lesser extent than when caused by a basicity increase when MgO content grows in slag at a temperature of 1450°С. © 2020, Allerton Press, Inc.

The sustainability of raw materials manufacturing industries is represented by the inscribed triangle and inverse triangle models. The significance of the inverse triangle is to satisfy the uncertainty when the upward triangle is facing multiple crises. The sustainability effectiveness is depending on indexes, indices, and variables that are used for evaluation. The indexes reduce the dimensionality problem, indices balance the equilibrium sustainability and variables determine the process capability. Sustainability evaluation of metallurgical value addition processes indicates that the modeling possesses some level of sustainability without satisfying the profit index. The level of sustainability is ineffective and susceptible to incurring a loss when applied to semi-finished products manufacturing. Therefore, the aspect of sustainability is the profitability of the value addition processes. The effectiveness of the model will quantify the triangles and criteria for uncertainty satisfaction. Hence, a case study is undertaken for estimating the sustainability of the Port-based Pellet and Pig Iron project owned by KIOCL Ltd., Panambur, and Mangalore. The indexes based evaluation of the metallurgical value-added process facility helps to reduce the complexity of the problem and computing difficulties.

This study aims to analyze the practices of iron ore pelletizing and Pig iron manufacturing units; considered as major value-added process facilities of iron and steel manufacturing plants. To achieve the concepts of cleaner production and sustainability demands, estimation of eco-efficiency of value-added process facility (VAPF). The technical procedure adopted was the case study; the data collection was done through direct observation and literature review. The main results were obtained from the analysis of company reports available to the public. The study concludes that the eco-efficiency of value-added process facilities increases when the VAPF adopts the utilization policy to make the ancillary products of higher market value. The existing value-added process facility shows the 74% eco-efficiency whereas the VAPF 4 shows 85% Eco-efficiency.

The problem of recycling of low-quality burden with increased content of harmful impurities and industrial and domestic metal-containing wastes becomes more and more actual. The solution of it will enable to decrease damage to environment and to obtain useful product out of the secondary raw materials. A concept proposed for creation of micro-metallurgical plants with less comparing with mini-mills, production capacity. The possibility of flexible control of processed liquid and solid burden materials ratio is an important advantage of the micro-mills, taking into account varying prices for raw materials and energy. In the preparation department of the micro-mill it is reasonable to use briquetting by means of two-high presses for pelletizing of fine-fraction materials, used as a part of initial burden. In the melting department depending on the kind of finished product a 130 m3 volume blast furnace or oxygen cupola furnace of 10-15 t/h productivity can operate. For steelmaking a 10-t oxygen converter with rotating housing or small-size EAF can be used. The casting department will provide production of marketable pig iron or steel ingots. It was noted, that in the countries of Europe at steelmaking plants of 50-150 thousand t/year productivity, steel-making facilities are used based on Kal-Do converter principle. A layout of mechanisms of such a converter, perfected by Ukrainian specialists presented. The perfected converter has a modernized drive of the housing rotation mechanism, automatic systems of bath bottom blow-down by an inert gas and gas-dynamic final technological slag cut-off at steel tapping into tapping ladle. New technical solutions, used in the steelmaking aggregate, allow to simplify the operation and maintenance of the housing rotation drive mechanism, as well as to expand the possibilities of technological process flexible control due to provision of rational combinations of the operations and techniques used. Approximate calculations of expenses for production of one ton of product under conditions of industrial metal-containing wastes recycling when using oxygen converter with rotating housing presented.

Substantial quantities of openly dumped slag contribute to the absence of recovery and utilization of valuable metals as well as potential environmental pollution to water and soil. Owing to the excessively high arsenic content present in iron extracted from copper smelting slag, we propose a new arsenic removal process in this paper. The results indicate that arsenic sulfides in copper smelting slag can be significantly removed at 1100 °C in an N2 atmosphere, leading to a 0.15% residual arsenic content. Furthermore, undecomposed arsenate in the slag can be reduced in an N2–CO atmosphere. During a coal-based direct reduction process, under optimal conditions, the removal efficiency of arsenic is relatively low. Subsequently, under optimal conditions, the arsenic content drops significantly from 0.18 to 0.080%. This new removal process engenders lower arsenic content in iron extracted from slag than the standards of pig iron and direct reduced iron in steelmaking.

Manganese alloys are important raw materials for steelmaking. However, selective mining of high-grade manganese ore resources has resulted in a scarcity of these high-grade Mn ores (Mn: >42; Mn/Fe: >5). The present research work is carried out to explore a new smelting reduction process to produce high-Mn/Fe synthetic Mn ore from low-grade ferruginous manganese ores. Representative samples of low-grade ores (Mn: 25–30%; Mn/Fe: ~1) were collected and smelting reduction studies were carried out using variable smelting power (20–30 kWh), carbon rate (10–20% of ore) and slag basicity (0.1–0.3) to produce high-MnO slag and manganese pig iron. Studies have shown that different-grade high-MnO slags (MnO: 38.57–58.24%; Mn/Fe: >15) and manganese pigs (Mn: 5.16–24%) can be produced at optimum process conditions. The high-MnO slag can be used as synthetic ore for the ferroalloy production process. The developed process is capable to effectively segregate the iron and manganese in the metal and slag, respectively. The optimum Mn and Fe separation (>95%) was achieved by smelting of 10 kg Mn ore batch in a 50-kVA electric arc furnace using 30 kWh smelting power and 0.16 kg of coke. The slag basicity was maintained at 0.3 and the optimum slag SiO2 was ~30%. The studies indicated that the upgrading of low-grade ferruginous manganese ores is a promising solution for achieving high-Mn/Fe-ratio synthetic ores for ferroalloy production. It can help the manganese alloy industry to overcome challenges associated with the scarcity of high-Mn/Fe-ratio Mn ores and efficient utilization of low-grade resources.

Iron ore reduction is a primary unit operation in current metallurgy processes and dominates the energy consumption and greenhouse gas (GHG) emissions of the iron-making process. Therefore, even a slight improvement of the energy efficiency or GHG emissions of iron ore reduction would yield considerable benefits to the cost of pig iron and, more importantly, to mitigation of the associated carbon footprint. The current study presents a discrete model that describes the iron ore reduction process for a single pellet. The transient reaction progress can be predicted and is validated against experimental measurements under various operating conditions, including different reducing gases and temperatures. The effects of pressure, isothermality, gas composition, and flow rate on reduction are investigated. The reduction rate increases significantly with increasing pressure until 5 atm, and the entire reduction process occurs more slowly under non-isothermal conditions than under isothermal conditions. This work provides a solid foundation for the development of a comprehensive particulate system model that considers both heat and mass transfer.

To make high-quality steel, it is necessary to ensure low sulfur content in the hot metal entering a steelmaking shop. The task to obtain low sulfur metal can be solved either during blast furnace smelting or its ladle desulfurization immediately after tapping out of blast furnace. Under conditions of JSC EVRAZ NTMK, the ladle desulfurization of vanadium hot metal is not applied, since it leads to a loss of vanadium. Is explained by the fat, that calcium oxide forms with V2O5 a strong calcium vanadate (3СаО·V2O5), which makes the process of vanadium recovery during further slag processing more complicated. Therefore the ladle desulfurization is accomplished after devanadation of hot metal. After the devanadation the semi-product has ions of oxygen, which makes it impossible to arrange an effective desulfurization and males it necessary to smelt the hot metal with limited sulfur content. The factors, effecting the process of hot metal desulfurization in a blast furnace, including slag basicity, MgO content in it, temperature of smelting products and slag viscosity, are presented. Dependence of distribution coefficient of sulfur on slag basicity has been shown. Research goal is pig iron desulphurization efficiency estimation by means of MgO increasing in slag. Data analysis findings about smelting products composition over 500 tappings for each of two investigated JSC EVRAZ NTMK blast furnaces have been reported. The aim of the study was comparison of hot metal desulphurization efficiency due to both slag basicity increase and MgO increase in slag. Results of data analysis on smelting products composition of over 500 heats for each of two investigated JSC EVRAZ NTMK blast furnaces have been presented. It was established that a sulfur content decrease in hot metal is achieved more effectively by MgO increase in slag. It has been shown that MgO has better desulfurizing properties, and with an increase of its content in the blast furnace slag, the overall technology for running the blast furnace process improves. It was recommended to increase the consumption of materials containing MgO while maintaining basicity at a constant level. Such a technology will allow to decrease sulfur content in hot metal, as well as will result in the process stabilization providing other conditions being equal.

The effects of CaO content, MgO content and smelting temperature on the vanadium behavior during the smelting of vanadium titanomagnetite metallized pellets were investigated. The thermodynamics of reduction and distribution of vanadium was analyzed and the high-temperature smelting experiments were carried out. The thermodynamic calculations show that the distribution ratio of vanadium between the slag and the hot metal decreases with the increments of CaO and MgO content in the slag as well as the increase of the smelting temperature. The smelting experiments demonstrate that the vanadium content in iron and the recovery rate of vanadium in pig iron increase as the CaO content, MgO content and smelting temperature increase, whereas the vanadium distribution ratio between the slag and iron tends to decrease. Moreover, the recovery rate of vanadium in pig iron has a rising trend with increasing the optical basicity of the slag. The addition of MgO in the slag to increase the slag optical basicity can not only improve the vanadium reduction but also promote the formation of magnesium-containing anosovite, which is beneficial to following titanium extraction.

This paper derives from first principles simple relationships that can be used to compute energy requirements for the production of hot metal (pig iron) in a blast furnace (BF) or direct reduced iron (DRI) in a direct reduction furnace (DRF), and the transformation of hot metal and DRI into crude steel in a basic oxygen furnace (BOF) or electric arc furnace (EAF) with the addition of scrap iron or scrap steel of varying purity. These relationships account for the impact of changing iron ore grade, in the amount and type of impurities in iron, and the impact of the addition of fluxes and the production of slag. Changing proportions of hot metal and scrap to the BOF, or of DRI and scrap to the EAF, are accounted for. The energy flow analysis presented here, combined with the mass flow analysis presented in a companion paper, provides a foundation for tracking the impact on energy use and iron losses of alternative pathways that might be used in the future as part of a broad-based effort to reduce energy use and associated greenhouse gas emissions.

Explored reserves of titanomagnetite ores of Suroyamskoe deposit in Chelyabinsk region is equaled to 11 billion tons. Construction of a new metallurgical enterprise may be relevant for their production and processing. The most promising is the traditional scheme of metal production: ore mining, its crushing and enrichment, production of agglomerate and pellets from concentrates, smelting of pig iron in blast furnaces and steel production in oxygen converters. To establish basic technological parameters of the new production scheme, pig iron smelting from sinter obtained from titanomagnetite ores of Suroyams-koye deposit and its further devanadation (to produce vanadium slag suitable for the production of ferrovanadium) were studied in laboratory conditions of Nosov Magnitogorsk State Technical University. At the initial stage, a calculation was carried out, than experiments in laboratory conditions were made. As a result, the technology was developed for smelting pig iron from sinter obtained from concentrate of Suroyamskoe deposit and its subsequent devanalization to produce two products: pig iron and vanadium slag. It has been established that it is advisable to obtain vanadium in it at least of 0.22 % when smelting pig iron. Dependences of the main indicator of devanadation effi-cience - the content of vanadium oxide in slag - on the concentration of vanadium in pig iron and the amount of slag were found. The fundamental possibility of de-exploitation of experimental Suroyamskii pig iron was confirmed with the production of vanadium slag containing up to 12 % V 2 O 5 with the use of air blast as an oxidizing agent.

Timely and full tapping of liquid smelting products is an important condition for forcing the blast-furnace process. Unstable tapping of iron and slag leads to fluctuations of the liquid level in the hearth, changes in the charging rate, and fluctuations in the time the burden stays in the blast furnace. This, in turn, affects the thermal state and the composition of the liquid products. The ratio of tapped slag weight to the hot metal weight is determined by the physical properties of slag and the length and diameter of the taphole. An analysis of the operation of the EVRAZ NTMK blast furnaces revealed substantial fluctuations of this ratio. When the volume of tapped slag is 340 to 360 kg per ton of pig iron, the slag/metal weight ratio is between 200 and 850 kg per ton of pig iron. The objective is to analyze the causes of unstable tapping and the effect of the instability on the furnace performances using the laws of fluid mechanics. It is assumed that the melt flow in the taphole is stratified. The effect of the slag properties and the dimensions of the taphole on the velocity of the melt and, hence, on the slag/metal weight ratio in the taphole is studied. Since the velocity of the melt depends on its physical properties, a mathematical model was developed to assess the slag/metal weight ratio from the viscosity of the slag and the dimensions of the taphole. The results of modeling are validated against the industrial data acquired by the EVRAZ NTMK. It was established that an increase in the tapped slag/metal weight ratio leads to worse performance and lower vanadium recovery from pig iron.

The functional capabilities, methodological foundations and information software of a modernized computer system for controlling the slag regime of blast furnace smelting, developed at the Institute of Ferrous Metallurgy on the basis of fundamental principles in the physicochemical and mathematical modeling of metallurgical melts and systems based on the concept of directional chemical bonding, are considered. The system provides a predictive calculation of the complex of technological properties of the final blast furnace slag: viscosity, melting points, enthalpy, and desorption capacity. Operational assessment of the slag regime using the Slag system as part of the process control system allows efficiently and up-to-date solving the problems of optimizing the slag regime and pig iron quality under unstable blast furnace conditions

Structure of the Russian export and import of steel industry products presented by results of 9 months of 2019 operation. It was shown, that the total share of pig iron, ferroalloys and semi-products (40.3%) in the ferrous metals export from Russia is practically the same as the share of rolled products and steel pipes (39.4%), whereas the shares in the import structure were 7.7 and 75% accordingly. The share the far abroad countries in the Russian export and import of finished steel products (in natural terms) accounted for 80.6 and 28.7% accordingly, while the share of CIS countries – 19.4 and 71.3% accordingly. For 9 months of 2019 the Russian export of semi-products declined by 10.9% comparing with the analogue period of 2018 and accounted for 10.9 m tons. 54.6% of the total export shipping of semi-products were directed to Mexico, Turkey, Egypt and Taiwan. Within the nearest years the Russian export of semi-products and billets, in particular, will be effected by the further development of the semi-products production in in the countries of Middle East, Turkey, Vietnam and India. The domestic market remained to be more attractive for many Russian companies. For the 9 months of 2019, export of long and flat products accounted for 3 and 5.7 m tons accordingly, declining comparing with the analogue period of the previous year by 11 and 15.6% accordingly. Import of long and flat products decreased by 12 and 0.5%, accounting for 1.0 and 2.9 m tons accordingly. By the results of 9 months of 2019, import declined and export shipping of coated sheet increased. Taking into account the expansion of steel grades assortment by Russian plants, increase of capacities for production of sheet with different coatings, this tendency is likely to remain.

The present study aims to develop composite (amorphous + nanocrystalline) coating using blast furnace (BF) pig iron composition with the help of atmospheric plasma spray process for the first time. The usage of cheap and lean chemical composition of pig iron for the development of economical composite coating on mild steel substrate has led to the improvement in its hardness as well as corrosion resistance in 3.5% NaCl solution. The corrosion resistance of the BF metal composite coating in 3.5% NaCl solution has rivaled that of the heavily alloyed (like Cr, Ni and Mo) 316L stainless steel coating. The as-sprayed coating has been characterized using x-ray diffraction, scanning electron microscope and transmission electron microscope. The improvement in corrosion resistance of composite coating can be attributed to the presence of amorphous, nanocrystalline phase and higher content of P and Si and protective rust phases.

Despite the fact that alternative processes such as Corex® and Finex® have already been established on industrial scale, the blast furnace route continues to be the most important process used to produce pig iron. Due to its importance, a variety of models of the blast furnace process have been developed in the past decades. In addition to this, a well-established analogue representation of blast furnace operation is given by the Rist operating diagram. The target of this work is to create a comprehensive blast furnace model in the simulation platform of gPROMS ModelBuilder®. Based on elemental assignments and empirical component distribution correlations, the blast furnace process is depicted by means of a black box model. The thermodynamic process boundaries are analysed in a Rist sub-model. Furthermore, an additional sub-model is used to calculate the adiabatic flame temperature in front of the blast furnace tuyeres. This modelling concept enables the description of interdependencies between the main blast furnace process, raceway conditions as well as overall thermodynamic process conditions within a single mathematical model. A detailed analysis of the model behaviour under varying coke substitution scenarios was carried out. The achieved simulation results demonstrate the applicability of the developed model for simulation of the blast furnace process under a wide range of operation conditions. The model also provides the means for simulation of different blast furnace route setups which allow for further optimisation regarding process efficiency, fuel consumption and environmental emissions of the blast furnace process.

We discuss the transportation of molten pig iron in hot-metal ladle cars and mixer ladle cars at metallurgical plants. It is determined that manual traffic management and entry of data on the amount transported in each ladle or mixer have the most significant impact on molten pig iron transportation efficiency. We review prior work on this problem.

The expenses of pig iron manufacturing stay in a relatively high level due to the large consumption of coke and ore. There are a variety of methods to optimize the ironmaking process, including multi-indexes method, production-oriented approach, and cost control strategy. In order to reduce the production cost, we optimize the raw materials supply schedule of an ironmaking plant with five sintering machines and seven blast furnaces. The ironmaking plant used to fix the feeding system, leading to an inefficient operation and mismatched connection between these two procedures. At first, the physical characteristics of each blast furnace is captured by linear regression model. Then, a self-adaptive genetic algorithm with variable population size is constructed under distribution system. Finally, the improved genetic algorithm is applied to optimize the total production cost represented by the aggregation of seven coke ratios on a cloud computing platform. With the application of this cloud collaborative optimization framework, the mean coke ratio of the ironmaking factory has decreased 13.96kg/t Fe.

In the iron manufacturing industry, it is unavoidable to produce large volumes of blast furnace slag (BFS) as a mineral residue from the preparation of pig iron in blast furnaces as well as to discharge a high volume of carbon dioxide (CO2) gas as a result of the consumption of coke. These byproducts potentially lead to environmental problems such as ground pollution and global warming unless they are treated. BFS is a complex oxide mainly composed of CaO, MgO, SiO2 and Al2O3. The former two have the ability to react with CO2, and SiO2 is a major component of mesoporous silica (MS). Herein, we report a direct route to convert BFS into a mesoporous silica-calcium oxide composite (slagCaO-MS) possessing high CO2 adsorption performance. A composite composed of SBA-15-like mesoporous silica with a pore diameter of 12.3 nm and crystalline CaO particles (mean surface area = 128 m2 g−1) was synthesized from BFS via a facile dissolution-hydrothermal process using formic acid as a dissolving agent, while the use of mineral acids (HNO3 and HCl) resulted in the formation of ill-defined low-surface-area materials with less CO2 adsorption capacities. The composite synthesized under optimum conditions was found to have a CO2 uptake value of 18.8 wt% per mass of adsorbent, and could be regenerated for at least 10 cycles. The green and low-cost adsorbent originating from BFS with high CO2 adsorption ability and reusability is advantageous for mitigating CO2 emissions discharged from the iron manufacturing industry, and will surely contribute to the sustainable development of the iron manufacturing industry.

Titanium slag is a basic raw material for production of titanium dioxide, widely used in various branches of national economy. Titanium slag is produced out of ilmenite concentrate. In Russian Federation there are several ilmenite deposits of ledge and placer type under various stages of development. Laboratory studies of ilmenite concentrates of Malyshevskoye, Irshanskoye and Medvedevskoye deposits processing technologies carried out. Two-phase technological scheme proposed, including ilmenite-coal briquettes reducing in an annular furnace and smelting of hot metallized briquettes in an ore-smelting furnace resulting in titanium slag and pig iron obtaining. Ilmenite concentrates were mixed with anthracite, bonding agent, briquetted and reduced in an annular furnace. After reducing the hot metallized briquettes were smelted in an electric furnace at 1650 ° С and the smelting products were casted into molds. The chemical and size composition of ilmenite concentrates and chemical composition of metallized briquettes presented. Technical indices of the annular furnace operation at metallized briquettes production and chemical composition of titanium slag and pig iron obtained out of the mentioned deposits ilmenite concentrates cited. It was determined, that the production of briquettes with high degree of metallization in the annular furnace is possible at heat treatment mode, providing a quick heating until the temperature of 1400-1500 °С. The cycle of the briquettes heat treatment in the annular furnace can be 15-30 min, including the phases of charging, heating, roasting, cooling and discharging. To study the heat treatment parameters effect on the process of coal-thermal reducing of ilmenite concentrates briquettes, a heat-physical model was elaborated. The model was based on studies of coal-thermal reducing kinetics of briquettes comprising ilmenite and anthracite, as well as zonal heat and material balances of oxidizing-reducing processes in the annular furnace. A technological scheme of titanium slag from ilmenite concentrates of Malyshevskoye, Irshanskoye and Medvedevskoye deposits proposed.

The article explores the time it takes to form a coating. Various combinations of materials are shown and the best option for creating a coating with the desired parameters is selected. Shows the effect of the coating composition on the change of microhardness

The Pedersen process is a method to produce alumina from Al-containing sources, and it is a more material-efficient method than the current commercial Bayer process, since the formation of bauxite residue (red mud) is avoided, and the bauxite can be holistically consumed. The smelting reduction (SR) part of the Pedersen process yields pig iron and a calcium aluminate slag, and the latter is a feedstock material for alumina extraction via alkaline leaching. In the present study, three different bauxite ores (Greek, Turkish and Jamaican) were smelted with lime to ease the process and control the slag chemistry and coke for the carbothermic reduction of iron oxides. The slags produced were analyzed with XRD, XRF, and EPMA to identify the phases and chemical compositions. According to the results, the slags composed of Al-containing leachable phases. Moreover, it is shown that the amount and distribution of both the leachable and non-leachable phases in the slags depend on the ore chemical composition. The results are discussed regarding the characteristics and potential leachability of the slags. Standard leaching tests were performed to examine the actual leachability.

Nodular cast iron is a fundamental material used in engineering. It has unique properties and is one of the most produced materials in the world nowadays. The production of nodular cast iron involves melting of raw materials such as steel scrap, pig iron, machining returns and alloy irons. With the development of increasingly technological steels through the addition of chemical elements to meet a specific application, there is an increasing difficulty in acquiring steel scrap content low alloy for the production of nodular cast iron. The chemical elements present in the steel scrap favor the appearance of unwanted phases and particles. The present study evaluated the effect of the addition of the elements copper, chromium, molybdenum and nickel in levels between 0.50% w and 1.0% w in the formation of nodular cast iron microstructure. While nickel and copper were evenly distributed in the matrix, chromium and molybdenum formed carbides. In addition, chromium strongly favored the formation of perlite in nodular cast iron and molybdenum, the martensite.

Steel slag from an electric arc furnace (EAF) may contain significant amounts of oxides of valuable metals. The recovery of iron and other metals from the EAF slag using smelt-reduction process was studied with coal as the reductant. A pig iron phase with high carbon and a final slag depleted of the valuable metals were generated. SEM-EDS and ICP analysis indicated that valuable metals could be successfully recovered in the pig iron. Nearly 84% recovery of Fe was observed with about 85%, 95% and 84% recovery of Mo, Ni and Co, respectively. In addition, 48% Cr, 30% V and 7% Mn were also recovered with a total metal yield of about 20%. An experimental design was developed using the three most important process variables, dwell time, reaction temperature and basicity, with a view to optimize the process and identify the most favourable process conditions. A total of 15 experiments were carried out per the Box-Behnken design using Response Surface Methodology. The response variables included metal yield, total yield, slag yield, Fe recovery, Cr recovery, Mo recovery as well as C and S content of the metal. Statistically significant empirical models for the response variables were developed and the process was optimized. The optimum was obtained at a dwell time of 20 min, reaction temperature of 1681 K and basicity of 1.025. The recovered pig iron with 3.32% C and 0.1% S is suitable for use in steelmaking as hot metal. The final slag may be used in construction applications.

The Si content in pig iron is one of the important indicators for evaluating the technical level of ironmaking in the blast furnace. From the late twentieth century, the production of low-Si pig ir...

Charcoal has several applications on both small and industrial scales. Nevertheless, its parallel production of approximately 70% in coproducts during the slow pyrolysis process is still considered a challenge, especially for producers in emerging countries. However, the Brazilian production model stands out positively compared to the other producing countries, considering that Brazil is the world’s largest charcoal and sole pig iron producer from a renewable natural resource. The aim of this work was to analyze the thermal behavior of wood during the thermochemical process and the macro-thermogravimetry of large wood samples in different moisture and diameter conditions, similar to those found in the production units in Brazil. The slow pyrolysis was performed using 30-cm-long logs. The highest temperature gradient of 280 °C was observed in the 14-cm-diameter and 40 wt% moisture logs. The wood heating rate during carbonization was nonlinear. The presence of water in the wood delays the charcoal production reactions by up to 50% and contributes to the formation of different thermal profiles in the wood. Thus, due to the nonlinear thermal profile of the transformation of wood into charcoal, thermal curves are an important tool to help the control systems of the charcoal production units.

Blast furnaces are one of the most common and economical ways to produce pig iron and steel. One of the most important pieces of a blast furnace is the blowpipe which transmits preheated air to the blast furnace. In this investigation, a failure of a blowpipe was performed. XRD and EDS analyses were used for phase and elemental analyses. The fractography and microstructure of the samples were examined by optical and scanning electron microscopy. The results showed that chromium carbide segregation caused embrittlement and fracture at grain boundaries.

The article presents the results of long-term studies on the preparation of ligatures for gray and high-strength cast iron, which are used for the casting of key parts of internal combustion engines (ICEs). The main purpose of the study is to extend the life of the components of the ICE by increasing the wear resistance of the main parts (cylinder liners and piston rings). The objectives of the study are to develop a ligature and technology for gray and high-strength pig-iron. The research methods included mathematical modeling by means of regression analysis of Gram matrices formed on the basis of the determined correlation coefficients between the wear resistance of cast iron and its chemical composition, which was checked by Fischer's criterion, as well as practical studies on the casting of pig iron of various brands and bench tests of engines with parts on their basis. The regression equation describing the optimal chemical composition of cast iron is given as I = 8.4 +0.9C- 0.6Si - 3.2Mn - 84.4P - 4.5Ti - 33.8S + 9.3Cr + 0.4Ni - 5 , 9Cu - 1,1V + 24,3Mo. The basis for the development was the analysis of a sufficient number of literary sources related to the dopant properties of different elements when applied in gray and high-strength pig-iron. The main results of the literary search are presented in the corresponding section, where doping with nickel, chromium, molybdenum, vanadium, copper, silicon, titanium and other elements is covered. It was developed and protected by patents of Ukraine No. 25099 and number 25100 highly effective ligatures for pig-iron parts of cylinder-piston group (CPG). The bench tests of hardness resistance of the received pig-iron showed that the formation of sorbitol perlite due to alloying of pig iron in the ladle is an optimal approach that in combination with other measures can significantly improve the quality of the obtained parts. Thus, studies have shown that for super-loaded parts of the cylinder-piston group, the inevitable transition to doped pig-iron is inevitable. For pig-iron for bushings of cylinders of diesel engines of type ЧН 25/34 it is connected with their transition to high-grade fuel, and the work of new forced engines 6CHN 26/34 without doped pig-iron was not possible.

Charcoal is an important source of renewable energy with great industrial importance as a bio-thermo-reducer in the production of pig iron and steel. To increase the quality and yield of charcoal, it is necessary to invest in the continuous improvement of carbonization kilns and in the control of the carbonization process. However, studies to characterize the technologies currently used in the production of charcoal are lacking. This paper aims to fill this research gap by searching for patent documents of kilns used worldwide in the production of charcoal. A total of 172 carbonization kiln patents have been found and most of them contain technological improvements. The following were emphasized: information on the structure of the kiln, means of mechanizing the loading and unloading of kiln, the reuse of gases and vapors from the carbonization process, control of the carbonization process, rapid cooling of the produced charcoal while it is still inside the kiln, and possible advantages of adopting such technologies. However, despite these technological advances, most of the world's charcoal production still comes from low-technology, traditional kilns, resulting in lower yield and variable charcoal quality. Also discussed are the reasons for the lack of consolidation in the production environment of technologies proposed by kiln patents, considering the fact that they could increase the yield and quality of charcoal and, consequently, reduce the demand for wood.

The processing of electric arc furnace dust by the Waelz process forms the iron-containing residue called Waelz slag. In the paper, best practices for recycling of Waelz slag from electric arc furnace dust processing have been analyzed and physicochemical characteristics and microstructure of the Waelz slag obtained from JSC Chelyabinsk zinc plant have been investigated. Chemical analysis of the Waelz slag composition has shown that it contains 26.4 wt % of iron with a metallization degree of 47 and 18.7 wt % carbon. It also contains about 1 wt % of zinc unevaporated during Waelz process. It has a complex multicomponent mineralogical composition. Analysis of papers has shown that currently Waelz slag recycles mainly in the construction industry in the production of cement, concrete, bricks and for road making. There is a limited number of papers devoted to recycling of Waelz slag in metallurgy because it contains too high values of contaminants such as zinc, lead, sulfur, phosphorus and copper. It is expedient to apply for recycling of Waelz slag the reduction smelting with obtaining of pig iron, slag suitable for construction industry and zinc-lead fume.

Iron sand as the largest form of iron ore reserves in Indonesia has not been optimized properly for domestic iron-steel production. In the production chain of pig iron from iron sand, there is a problem that in sponge iron (result of direct reduction) contains many impurities, especially titanium. This research is conducted to determine the effect of additive variation to the Fe content and Fe recovery during sponge iron smelting process into pig iron using electric arc furnace (EAF). Types of additives variation that used in this research are CaCl2 and CaC2, as well as smelting without additive as comparison. Briquettes made from sponge iron, coal, flux (SiO2), and variations of additive are melted in crucible using EAF (16.2 Volt; 180 Ampere) for 6 minutes. Based on EDX and XRD results of pig iron and slag, the optimum process of sponge iron smelting is use the CaCl2 as additive. It’s shown by the result that the pig iron containing the highest %wt Fe by 90.97% and the highest Fe recovery by 80.41%. The product that used CaC2 as additive has Fe content of 89.31 %wt and Fe recovery during process of 72.36%. Meanwhile, the results obtained from the smelting without additives only shows that the Fe content in pig iron amounted to 88.90 %wt and 68.76% values for Fe Recovery.

The authors proposed the selective reduction of P from steelmaking slag to enable the recycling of steelmaking slag for the sintering process, and for the extraction of P and Mn separately. By decreasing the basicity of the slag and increasing the temperature of the reduction, Fe and P were reduced to the metal, while most of the Mn remained in the slag. In this study, this selective reduction technique was applied to a kind of Mn ore to remove P. The influences of the different mixing ratios of graphite, SiO2, and pig iron as well as the temperature on the reduction behavior were investigated. By adding SiO2 as a slag modifier to produce an acidic slag with a low melting temperature and adding graphite and pig iron as a reductant and receiver, respectively, the selective reduction of P without the reduction of Mn was achieved for Mn ore. When the slag obtained after the selective reduction of Mn ore was used in the smelting reduction process to produce the ferromanganese alloy, a significant decrease in the P content of ferromanganese was estimated through a mass balance calculation. Therefore, the selective reduction of P from Mn ore has the potential to produce high-grade ferromanganese alloys with low P content.

Stainless steel pickling sludge (SSPS), generated from the lime neutralization process of spent pickling liquor, is classified as a hazardous waste consisting of abundant metals like Fe, Cr and Ni, and other elements like F, S and Na, etc. Rather than a common disposal in landfill, recovering these metals and other valuable components from SSPS can not only create economic benefits, but also eliminate its adverse impacts on human health and the environment. A review of the formation mechanism and basic properties of SSPS was made, and the technical features, advantages and limitations of a series of pyrometallurgical treatment processes were summarized. Based on these, the main challenges for recycling of SSPS through the existing techniques are demonstrated. The traditional pelletizing/sintering-blast furnace process can only be used as a partial solution. Direct use of SSPS as flux in an argon–oxygen decarburization converter or electric arc furnace is a promising way, but low S sludges are preferred. The STAR process shows excellent recovery for metals, but it also has a low tolerance to the S and F contents in SSPS. And the INMETCO process is highly flexible in treatment of various wastes, whereas it exhibits relatively low Cr recovery and produces poor-quality pig iron. In addition, the feasibility of the rotary kiln-electric furnace, solid-state reduction of chromite and reduction-magnetic separation processes requires further studies. An urgent task at present is to develop a system for scientific classification and separate collection of SSPS in terms of chemical composition, notably S and F contents.

In this article, we introduce the excavation of an iron smelting site at Xuxiebian 許鞋匾, Pujiang 蒲江 County, Sichuan 四川 Province in the PRC. Two excavations were carried out in 2007 and 2011, and a total of four bowl-shaped furnaces, five pits, two trenches, and one posthole were excavated. The site is dated from the mid-late Eastern Han dynasty to the Jin dynasty (ca. AD 150-420) according to the local pottery assemblage. It is possible that the sole functions of the Xuxiebian site were the production of pig iron ingots and the conversion of pig iron to wrought iron. The iron ingots were likely transported to areas with stronger administrative control by the central government near the ancient city of Chengdu or even to the Central Plains, where they were then cast into different objects.