Volume 48, Nº 10 (2018)

In industry, nonuniform distribution of the material and energy resources significantly affects the stability of production processes and impairs product quality. In particular, in blast furnaces, nonuniform distribution of the batch components and the gas temperature significantly affects furnace performance. A literature review shows that the nonuniformity is usually assessed by means of various coefficients taking account of the variability in the material and energy resources in the course of production. The variation coefficient introduced by Pearson in 1895 is most commonly used. The relation between the square of the variation coefficient V² and X² = [n(N–1)/N]V² is established. According to this relation, the random quantity V² has a χ²_k distribution with k degrees of freedom: k = N–1. Here n = n₁ + n₂ + … + n_N; n_i is the ith measurement (\(i = \overline {1,N} \) ); and N is the total number of measurements. The proposed method of assessing the nonuniformity is based on the statistics χ²_k and X², as proposed by Pearson in 1901 and 1904, respectively. Here X₀ is intended for verification of hypothesis H₀: that the empirical and statistical distributions agree. The azimuthal nonuniformity of the distribution of materials and gases in the blast furnace is based on the consistency of the Pearson statistics χ²_k and X². The quantile factor q is employed if the calculations of X² do not employ the frequency of the measured quantities but, by analogy, the magnitudes of the physical quantities. In this method, after correction, X² is used to assess the deviation p from a uniform distribution (the nonuniformity factor): p = p(χ²_k), p ∈ (0; 1–α); χ²_k= X²_co-qX². If X² and χ²_k are to be consistent for measurements of physical quantities (the temperature or pressure) or of materials (friable materials, gases), X² must be corrected so that qX²_max ≈ χ²_k(α), X²_max ⊂ (X²₁, …,X²_M), where M is the number of experiments for which X² is determined; χ²_k(α) is the upper α quantile of χ²_k; q is the quantile factor introduced for correction of X²; X²_max is the limiting value of X²_max permissible in determining the nonuniformity measure. The method is tested in estimating the relative nonuniformity of the batch components and the distribution of the azimuthal temperature for 2014- and 1370-m³ blast furnaces at OAO Magnitogorskii Metallurgicheskii Kombinat. The influence of the sequence in which the batch components are selected in the bunker of the nonconical furnace-charging system on the azimuthal nonuniformity of the materials and the smelting characteristics is analyzed.

The proposed socially oriented information technology is based on the integration of diversification and technological processes for the creation of additional products and infrastructure, by stepwise structural synthesis of waste processing and land reclamation. The technology relies on empirical assumptions, theoretical principles, models of the decrease in environmental impact, assessments of the requirements, practical results, and verification criteria. The main approaches to decreasing the environmental impact include prevention of environmental damage; the introduction of a complete resource-utilization cycle; reconciliation of the interests of state agencies, investors, property owners, and other stake holders; and the stepwise integration of waste processing, recultivation of degraded land, and the creation of social infrastructure. The conceptual model for decreasing the environmental impact makes coordinated use of the primary and secondary products of waste processing and land restoration, with subsequent infrastructure creation. The outcomes of socially oriented information technology are specific, interpretable, verifiable, reliable, complete, and consistent. On the basis of the proposed tool set, scenarios are developed for improving the environmental conditions in the city of Novokuznetsk, which is located in the vicinity of metallurgical enterprises. In these scenarios, industrial wastes are used in the production of raw materials for the steel industry, building materials (bricks, concrete additives), and agricultural fertilizer. Predictions are made up to 2037, in terms of economic impact, area of recovered land, environmental pollution by productive activities, population of the region, relevant standards, and the pollution prevented per capita. Construction of the new system is planned for 2019 and 2020, with operation in 2021. Stepwise construction of the social infrastructure will begin in 2033. Simulation indicates the annual growth in predicted indices under the various scenarios, on account of synthesis of waste processing and land restoration, as well as decrease in the pollution thanks to low-waste and zero-waste production.

Coke production has numerous serious environmental impacts (atmospheric emissions of pollutants, wastewater emissions, solid-waste storage). To reduce such impacts, the local environmental and economic system and its basic components must be studied in order to improve plant management. In the present work, existing approaches to determining the operational features of industrial enterprises as local environmental and economic systems are analyzed; their modification is considered. This analysis provides the basis for a set of correlated environmental and economic indices reflecting the specifics of a coke plant with a narrow production program (specifically, PAO Koks). It is particularly important to understand the relationship between the following pairs: the current environmental protection costs and the risk level; the current environmental protection costs and fees for environmental damage; the current environmental protection costs and the compensation factor for the economic harm; and the utilization of production resources and the risk level. It is evident that the coke plant has pursued different environmental policies at different times: from 2004 to 2010; and from 2010 to 2016. By the analysis of theoretical developments in Russia and elsewhere and the analysis of graphs of actual plant data, means of improving the management of the coke plant as a local environmental and economic system are identified. From this perspective, it is important to make better use of current expenditures on environmental protection by redistributing the total among specific budget items and by devising a management algorithm for the wastes generated at the plant such that they may be converted to a commercial product, with decrease in waste-storage fees. This research is of practical interest for large industrial enterprises with numerous negative environmental impacts, so as to identify effective environmental management strategies.

The forging of high-alloy 13Kh17N14M3 and 08Kh18N10T steel ingots (mass 5.3, 1.5, and 1.2 t) is considered. Five forging technologies based on microshear are considered: natural shear in forging by traditional tools, insertion hammers; and hybrid hammers; and applied shear in forging by hammers with working surfaces that cross in the transverse vertical plane. In forging with macroshear, the reduction is 1.78, while the total reduction in the ingot is 2.44. For all the forgings, the deformation of the metal is satisfactory, with no residual cast structure. The mechanical properties of the metal considerably exceed the standard requirements.

An energy-saving technology is proposed for the manufacture of high-strength fasteners (strength class no less than 8.8) on the basis of the principles adopted in thermal–mechanical–thermal technology (TMT technology). This technology is tested in industrial conditions. The technology relies on cumulative increase in the strength at all stages of production: wire rod → blank → fastener. The proposed technology decreases the energy consumption in the manufacture of high-strength fasteners and so increases their competitiveness in the global marketplace.

An algorithm is developed for simulation of phase transitions in the solid state. The algorithm permits the derivation of the corresponding kinetic curves for different initial conditions (quantity and configuration of new-phase nuclei, distance between the closest nuclei). The results of simulation are analyzed by means of the Johnson–Mehl–Avrami–Kolmogorov equation and the logistical function for determining the corresponding coefficients. Analogies are established between the results of simulation and the experimental kinetics of isothermal transformation of austenite in alloy steel.

Research on the electrosmelting of reduced iron-ore pellets and briquets in an arc furnace permits the development of a method of burning the waste gases in three zones of the furnace, by the supply of pellets through tubular (hollow) graphitized electrodes in the furnace bath. The smelting of the pellets at the fuel–oxygen burners and oxygen tuyeres is intensified by ensuring the combustion of the waste gases above the melt in the furnace. The combustion rate of the waste gases in the furnace’s working space is monitored in the gasexhaust channel by means of sensors recording the content of CO, CO₂, H₂, O₂, and other gases. On the basis of the results, the heating and melting of the iron-ore pellets may be accelerated, as well as the heat and mass transfer between the metal, the slag, and the working gas in the furnace. In addition, the thermal and economic indices of pellet electrosmelting in arc furnaces may be increased.