Distribution of oil from oiled scale between various types of waste from blast furnace dedusting plant: dust, sludge, and slime water was estimated by physical modeling using a vertical tubular electric furnace. According to the mathematical modeling of thermal state of a metal container with oiled scale, intensive evaporation of oil in a blast furnace begins after it is loaded and lowered along the shaft to a depth approximately corres­ponding to three feeds. The oil was passed through a layer of sinter and pellets of the Mikhailovsky GOK heated to 500 °C with a mass of 0.6 kg and a particle size of 10 – 12 mm. Together with oil vapors, finely ground material was injected into the layer of iron ore raw materials (IORM), which imitated in component and fractional composition a mixture of blast furnace dust and sludge from a vacuum filtration plant (VFC) of blast furnace shop, taken in a ratio of 36:64. The physical modeling ensured compliance with the actual gas-dynamic mode in the area of blast furnace ore ridge, based on equality of the Reynolds criterion. The value of this criterion, equal to 215, was achieved in the laboratory model when argon was supplied with a flow rate of 70 L/min. According to the experimental results, distribution of oil was, % of the initial amount: 74.8 % decomposed on the IORM layer corresponding to three feeds; 9.1 % turned into blast furnace dust; 15.9 % turned into VFC sludge; there was no oil in the wet gas purification water; 0.2 % (30 mg) of the oil underwent wet dedusting in the form of an aerosol; a small amount of soot was observed on the pipeline walls. Gas phase of oil decomposition contained: 70 – 90 % H₂; 1.5 % CO; 0.5 – 7.0 % CO₂; 3.2 – 22.2 % CH₄; 0.1 – 2.5 % Σ(C₂H₄, C₂H₆, C₃H₆, C₃H₈). The content of benzo(a)pyrene controlled in Russia in oil vapor did not exceed 0.00058 %.

Using an electrolytic model, the authors investigated the operation of a ferroalloy furnace with increased electrode diameters and power. A traditional aqueous solution with a concentration of 0.2 % NaCl was used as the working fluid. Diameter of the electrodes was increased from 30 to 150 mm. The parameters of furnaces with a capacity from 7.5 – 10.5 to 81 MV·A during ferrosilicon smelting correspond to the results of simulation experiments, which were confirmed during the smelting of 45 % ferrosilicon in industrial furnaces with similar relative technological parameters. The type of dependence of the decrease in bath resistance on the increase in electrode diameter for industrial ferroalloy furnaces is similar to the dependence obtained as a result of modeling experiments. The factor of a significant decrease in the bath resistance due to an increase in electrode diameter for ferroalloy furnaces of different capacities during the smelting of a single alloy is very significant. With an increase in current strength of the elect­rode, electrical efficiency, the furnace power factor and the share of active power in the bath decrease. Analysis of the furnace parameters during smelting of 45 % ferrosilicon confirms the conclusions of electrolytic modeling of ferroalloy furnaces about the significant role of increasing the dia­meter of furnace electrodes in reducing the bath active resistance.

Gas analysis is one of the key methods for assessing the quality of atmospheric air in populated areas, as well as in the work area of production facilities. Atmospheric air monitoring is especially necessary at facilities that have a significant negative impact on the environment, in parti­cular, at ferrous metallurgy enterprises. The peculiarities of the gas analyzers used for air quality monitoring system are their sensitivity and selectivity. To achieve these indicators, a properly selected sensing element is needed: a gas analyzer converter. Synthesized solid solutions of semiconductor binary components, which proved themselves to be good adsorbents, are proposed as materials for the manufacture of converters. In this paper, the authors examined semiconductor systems consisting of ZnTe and CdSe, conditions for synthesis of the solid solutions based on them, and methods for their identification, which allowed the obtained materials to be certified as solid substitution solutions with cubic spha­lerite and hexagonal wurtzite structures (depending on the composition). X-ray, micro-, electron-microscopic, and IR spectroscopic studies of solid solutions made it possible to understand the surface structure of adsorbents. Results of the studies of the surface chemical composition, acid-base properties of solid solutions and binary components of the system allow us to conclude that the Lewis and Brønsted acid centers responsible for CO adsorption on the surface are present on the surface. In the ZnTe – CdSe systems, there is a tendency to move from a slightly acidic region to a relative increase in the surface basicity with an increase in ZnTe content. When materials are placed in a CO atmosphere, gas adsorption on the surface of solid solutions occurs in the same dependence, which was confirmed by the direct catalytic studies. The established patterns of changes with the composition of bulk and surface properties allow us to recommend new obtained materials as primary converters of sensors.

A new class of materials created at the beginning of the 21st century – high–entropy alloys – attracts the attention of researchers in the field of physical materials science. Based on the analysis of recent literature data, the current state of the problem of creating and researching medium- and high-entropy high-speed steels is considered. Due to solid-solution hardening and nano-precipitation hardening based on medium- and high-entropy alloys of complex composition, it is possible to create high-speed steels with high hardness, thermal resistance and impact strength. The presented results of studies of tribological characteristics and microhardness of high-speed steels indicate the dependence of these characteristics on entropy. The lowest values of cutting forces and contact temperatures are typical for cutting tools made of high-speed steel with a high level of entropy. Thus, when developing new high-speed grades, preference should be given to the compositions with a high level of entropy, since they provide better tribological characteristics and higher wear resistance. The structural and phase state of surfacing of high-entropy high-speed molybdenum steel of non-equiatomic composition on medium-carbon steel in a nitrogen medium was studied by the methods of modern physical materials science. X-ray spectral analysis methods determined the elemental composition of surfacing outer layer, and X-ray phase analysis revealed that solid solutions based on α-iron (88 wt. %) and γ-iron (12 wt. %) are the main phases of the deposited layer material. The calculation of the configuration entropy of this high-speed high-entropy steel gives a value of 1.93R (where R is the universal gas constant). The conclusion is made about the relevance and prospects of the development and research of high-energy alloys.

The considered analytical method for determining the optimal mode of hardening pulsed laser treatment (LT) of tungsten-cobalt hard alloys is based on the study of the patterns of temperature field formation during hardening of hard alloys, determination of thermal stresses occurring in the laser exposure zone (LEZ) during laser pulse treatment, and their comparison with the stresses of fracture of the alloy individual structural elements. The optimal modes of hardening LT of the alloys of WC group are considered to be modes that meet two criteria. First, the temperature on the LEZ surface should be in the range of 1290 °C < T < 1400 °C, when the alloy does not contain weakening it phases of the η-Co₃W₃C, θ-Co₃W₂C, or χ-Co₃W₉C₄ types, and increase in grain size of the carbide phase is insignificant. Secondly, cracks of an arbitrary scale are unaccep­table in the LEZ, that is, the thermal stresses resulting from the fracture should not exceed the stresses of fracture of the alloy structural elements. The calculation of thermal stresses occurring in a hard alloy during LT within a single carbide grain was carried out in accordance with the Hooke’s law. Calculations performed for both single and multiple treatments allow us to establish that for all the studied modes, with variations in the laser energy density from 0.9 to 1.8 J/mm² and treatment multiplicity from 1 to 10, when the surface temperature is in the range of 1290 – 1400 °C, the thermal stresses in the carbide phase are lower than minimum fracture stresses and do not exceed 80 MPa. The proposed analytical method for determining the limiting energy characteristics makes it possible to establish pulsed LT modes that provide dispersion hardening of hard alloys of the WC group in the absence of destructive changes in the material. The data obtained on defect-free LT modes are in good agreement with the earlier results of measurements of acoustic emission signals during treatment of hard alloys (VK8 alloy).

The article solves the problem of determining the temperature of calibrated strikers in a unit of combined casting and deformation during production of hollow steel billets. The authors substantiate the relevance of determining temperature fields and thermoelastic stresses in calibrated strikers when compressing the wall of a hollow billet and at full speed when cooling the strikers with water, and describe the strength and thermophysical properties of the steel from which the strikers are made. Geometry of the striker for producing a hollow billet in one pass is shown. The paper considers the initial data and temperature boundary conditions for calculating the temperature field of the striker during production of hollow billets in a unit of combined casting and deformation. The boundary conditions are given to determine the striker temperature as well as the values of heat flow and effective heat transfer coefficient. The results of calculating the temperature fields are performed in four sections and are presented for cha­racteristic lines and points located on the striker contact surface and in the contact layer at a depth of 5 mm from the working surface. Dimensions of the finite element grid were used in calculating the temperature field of the strikers. The temperature field of the strikers with collars was determined based on solution of the unsteady thermal conductivity equation with the corresponding initial and boundary conditions. The values and patterns of temperature distribution in a calibrated striker are presented when the wall of a hollow billet is compressed and when a hollow billet is produced in one pass in a unit of combined casting and deformation.

The objective of this theoretical study is to evaluate the effect of annular temperature seams in the inner surface of a spherical metal casting mold on the level of stress-strain state (SSS) in it during crystallization of a steel casting. The specificity of this technological process consists in the geometric shape (sphere) of the casting model, when the crystallizing metal creates significant compressive stresses in the inner surface of the mold (in the first moments), which are enhanced by the mold curvature: the mold inner layer, heating up, tries to increase in volume, but this is prevented not only by the cooler outer layers, but also by curvature of the surface layer itself. Two possible applications of the casting mold are being considered: with and without seams. The problem of optimizing the design parameters of temperature seams (recesses) is formulated. It depends on the magnitude of the normal stresses occurring in the casting mold at the initial stage of the steel casting crystallization. When solving the problem, the equations of the linear theory of elasticity, the equations of thermal conductivity and the proven numerical method are used. The paper presents a numerical scheme and a developed algorithm for solving the problem. Crack resistance was estimated based on the magnitude of normal stresses in a spherical metal mold. The optimal design options (schemes) of a spherical metal casting mold found as a result of solving the test problem depend on location of the temperature seams in the shell mold, the stress values in them under conditions of the min-max objective function and the developed algorithm. The results of solving the problem are presented graphically in the form of plots of stresses and temperatures in the studied area in different sections and periods of cooling of the shell mold and the metal growing crust. The obtained results of resistance of a metal spherical casting mold were analyzed.

The paper considers the features of producing granular pig iron using an annular furnace with a rotating hearth during implementation of ITmk3 technology (Ironmaking Technology Mark Three). The design of a coal gasifier with a synthesized gas purification system and the cross-section of an annular furnace are shown. The article briefly describes the process of industrial production of granular high-quality pig iron. The prospects of using the technology in question on the territory of the Russian Federation were assessed. At the first stage of research on the metallization of iron-ore concentrate (IOC) with coal, the thermogravimetric method of a complete factor experiment was used to determine the optimal metallization conditions. In the experiments, the ratio of IOC was varied: coal, size of coal, lime additives as a percentage of the amount (IOC + coal). As a result of thermogravimetric analysis, the authors obtained the curves of changes in mass of the samples, composition and amount of released gas when the heating temperature changed during sintering of IOC with coal and lime. At the second stage, a laboratory chamber furnace with a portable hearth, heated by generator gas from coal, was developed to test the ITmk3 technology. Ore-coal briquettes were made with a ratio of IOC, coal, bentonite 80:20:5 and heat-treated in a chamber furnace with heating by generator gas from a coal gasifier. Iron-ore concentrate from the Korshunovsky MPP and Kasyanovsky coal from the Cheremkhovsky deposit were used as experimental raw materials. Based on laboratory studies, the authors determined the temperature-time firing mode of ore-coal briquettes, which ensures a high degree of metallization of iron-ore materials of 80 – 87 % when firing briquettes in the temperature range of 1080 – 1424 °C for 40 min. The yield of briquettes after drying and firing was determined to be 66.45 %. The mechanism of solid-phase reduction of iron-ore materials in annular furnaces with a rotating hearth and liquid-phase separation of reduction products is considered. The composition of the gases released during calcination of ore and coal briquettes was determined.

The article is devoted to the topical issue of increasing the efficiency of rotary kilns used in the production of metallurgical lime from chalk. Methods of improving the structures and thermal operation of these units are considered, which is especially important in modern production conditions. The work begins with a description of the importance of lime in the metallurgical industry and the specifics of using rotary kilns as the main units for its production. There is a need to increase productivity and reduce energy consumption. The article provides an overview of promising technical solutions, such as: design changes, optimization of heat exchange devices, improvement of burner mechanisms, introduction of automatic control and process control systems. The results of tests confirming the expediency of using chalk of certain brands are also considered. Attention is drawn to the importance of factors such as the quality of raw materials and the qualifications of service personnel that affect the firing efficiency. The authors proposed new technical solutions to increase the efficiency of roasting process and reduce energy consumption. The article discusses the main problems associated with the production of lime from chalk. The proposed improvements are aimed at solving the mentioned problems and improving the quality of the final product. Special attention is paid to optimizing the thermal mode of the furnace; this will make it possible to use thermal energy more efficiently and reduce fuel consumption, which in turn will lead to reduction in the cost of lime production. Implementation of the proposed technical solutions will significantly increase the economic and environmental efficiency of lime production. The article emphasizes that continued research in this area is promising for improving the performance of rotary furnaces and, consequently, the quality of the resulting product.

The article discusses the development of an information modeling system for assessing the instability of a blast furnace. The presented approach is based on the application of mathematical models and methods for analyzing the parameters of the blast furnace process, which makes it possible to assess the impact of technological and organizational factors on the furnace stability. The developed system is designed for automated collection, processing and analysis of data in real time, as well as forecasting technological deviations. The methodology is based on the use of integral stability indicators, including the technical and economic characteristics of smelting, the properties of raw materials, the parameters of blast, gas dynamic, thermal and slag modes. To determine the integral indicators, a set of controlled and calculated features is used, ranked according to the degree of significance. The main modules of the system include functional blocks for data collection, calculations, analysis and visualization. The system architecture is implemented on the basis of a client-server approach, which provides the possibility of integration with existing metallurgical production management systems. The practical implementation of the system makes it possible to improve the performance of blast furnace smelting, reduce fluctuations in the parameters of the technological process and improve the quality of the resulting cast iron. The above calculation examples confirm effectiveness of the developed tool. The presented results may be useful for the specialists in the field of blast furnace production automation, as well as for the researchers involved in analysis and forecasting of instability of technological processes.

The main trough of a blast furnace represents a complex technological structure that plays a critical role in the ironmaking process by draining molten cast iron and slag from the furnace hearth, thus ensuring the continuity and safety of the process. The reliable operation of the trough directly impacts the blast furnace productivity. The trough must be designed to withstand extremely high temperatures and aggressive chemical environments, and its proper functioning requires constant monitoring and maintenance. Selection of refractory materials and lining technology, as well as the potential for enhancing the resistance of refractory linings in the main mining troughs and extending their service life, are contingent on the timely acquisition of information regarding the thermal load on the refractory layers and casing, the operating conditions, design characteristics, and destruction processes of refractories in interaction with cast iron and slag. The control systems of the blast furnace main mining trough are designed to ensure its safe and efficient operation, by detecting deviations from normal mode in a timely manner and preventing emergency situations. These systems include visual, instrumental and automatic control. The monitoring system of the main mining troughs heat-up will allow the blast furnace technological personnel to control the condition of troughs, estimate their remaining life and make timely decisions on their repair. The developed mathematical model of the blast furnace main trough lining condition takes into account real-time thermocontrol of the blast furnace mining trough casings. It is aimed at obtaining operative information on the main mining troughs heat-up, and is based on the solution of the problem of stationary heat conduction of a multilayer flat wall, each layer of which is a homogeneous wall.

A known cause of flat shape defects in finished cold-rolled steel strips is the inequality of the drawing ratios across the strip width. Difference in the values ​​of these ratios is affected by the roll barrel profiling parameters, energy-power parameters of rolling, operating parameters of the automatic profile and strip shape control system. The impact of all technological factors on the strip shape is complex. The paper considers an approach that takes into account the main operating parameters of rolling equipment allowing to estimate the type and amplitude of flatness defects in finished steel strips. When implementing this approach, 6 calculation stages were performed: energy-power calculation of the cold rolling process; calculation of elastic deformations of the working roll barrel surface; assessment of wear of the working roll barrel surface; calculation of the roll thermal profile; assessment of convexity of the steel strip transverse profile; assessment of flatness indicators of the finished strip. To calculate the parameters affecting the flatness of the rolled product, known calculation methods adapted to specific process conditions were used. The results of assessing the shape indicators of the rolled strip obtained using the model were compared with the results of modeling in the Deform 3D program. The modeling results demonstrated reliability of the proposed approach to assessing the rolled product quality.

Oxidation and reduction of metals consist in the loss of valence electrons by metal atoms with the conversion of an electromagnetic metallic bond into an ionic bond during oxidation and the reverse transition of electrons from anions to metal cations with the conversion of an ionic bond into a metallic bond during reduction. The electronic reduction theory developed by the authors describes the reduction process by the sequential operation of two electrochemical cells: a fuel cell, in which the chemical energy of the oxidized reducing agent is converted into electrical energy of “free” electrons, and a solid electrolyte electrolyzer, which converts the electrical energy of these electrons into energy of the metal bond of the reduced cations in the oxide. Since the stage of the actual reduction is the formation of a metallic bond between cations due to electrons coming from outside, the shortest and therefore most effective supply of electrons to the reduced cations will be not from the fuel cell, but from the electrical network, that is, electrolysis of the oxides of the metal being reduced. Known methods for producing iron by electrolysis of molten oxides, as well as possibly alkaline solutions, are promising for extracting iron from rich ores. For the selective extraction of iron from ferromanganese, titanomagnetite, siderite, chromite and other complex ores, relatively low-temperature reduction of iron with hydrogen or solid-phase electrolysis to produce, after separation, a metallization product by melting carbon-free iron and a concentrate of active metal oxides is more promising.