Browsing by Author "Ivashchenko, Valerii P."

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Complex Solid-Phase Reduction in a Blast Furnace of Self-Healing Pellets of Cold Agglomeration Containing By-Product Carbon Materials of Metallurgical Production
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Vaniukov, Anton A.; Ivashchenko, Valerii P.; Ivanova, Liudmyla Kh.; Kovalov, M.; Tsybulia, Ye.
ENG: The reactions of direct and indirect reduction occurring during the heat treatment of self reducing pellets (SRP) have been studied. In this investigation Blast furnace (BF) sludge which contains particles of coke, has been included in the SRP blend as a source of solid reductant. In the SRP as a part ot the blast furnace burden occur the reactions simultaneously: inside of SRP-direct reduction by Csolid; gasification of carbon and indirect reduction by CO; and outside of SRP-indirect reduction of iron bearing oxides by reducing gas coming from the hearth of blast furnace through the column of charged materials. The experiments was performed continuously from the start temperature (~200 ˚C) to the experimental temperature (500 ˚C; 700 ˚C; 900 ˚C; 1100 ˚C) in argon free environment. Upon reaching the desired temperature argon was replaced by hydrogen during 30 minutes. After that the reduced probe of SRP was cooled in argon. The objective of the present work is to research a quantitate ratio of degree direct reduction inside of SRP and degree of indirect reduction outside of SRP on the top of the blast furnace.
Development of Fast Spheroidizing Annealing Modes and Modeling of the Intensification Process of Cementite Spheroidization of Low-Carbon Steels
(TECHNOLOGY CENTER PC, Kharkiv, 2026) Shvachych, Hennadii H.; Sobolenko, Mariia O.; Ivashchenko, Valerii P.; Manko, Tamara; Moroz, Borys; Meshcheriakov, Leonid
ENG: The object of research is the process of cementite spheroidization of 20Г2Р low-carbon steel 2during heat treatment, in particular spheroidizing annealing. Special attention in conducting research is paid to the influence of the initial structural state of the steel, temperature regimes and heating methods on the formation of the microstructure of the workpiece. Traditional methods of spheroidizing annealing are characterized by a significant duration of the regime, which reaches more than 10 hours and, in connection with this, energy costs, which limits the efficiency of the technological process. This is especially true for low-carbon steels with a relatively weak thermodynamic stimulus for spheroidization. The research problem is the need to reduce the duration of spheroidizing annealing of steel and reduce energy costs while ensuring a uniform distribution of cementite globules in the ferrite matrix. The scientific novelty of the obtained results lies in the development of high-speed regimes of spheroidizing annealing of 20Г2Р steel using the initial ferritic-bainite structure and non-isothermal holding with increasing temperature, in contrast to known studies based on long isothermal holdings. It is shown that the total duration of spheroidizing annealing of low-carbon steels significantly depends on the initial structural state of the workpiece. It is established that the transition from ferritic-pearlitic to ferritic-bainite initial structural state provides a reduction in the duration of cementite spheroidization from 1500–1800 s to 200–450 s. The features of the intensification of spheroidizing annealing of low-carbon steels have been studied and the influence of changes in the values of thermodynamic and kinetic factors during structural transformation has been established. The effectiveness of using non-isothermal holding with increasing temperature in a certain temperature range and optimization of spheroidizing treatment parameters has been proven. The practical significance of the results obtained lies in the implementation of the developed high-speed modes of spheroidizing annealing of 20Г2Р low-carbon steel for the production of coiled strip and wire with a diameter of 6.0–20.0 mm. The obtained structural states of the blanks provide the necessary set of properties for the subsequent manufacture of metal products by cold drawing, in particular products of complex configuration. The proposed approaches are fully suitable and meet the requirements for technological and mechanical properties of blanks for the manufacture of metal products by cold drawing.
Improvement of Pig Iron Production Technology by Using the Useful Properties of the Potential of Secondary Resources of Raw Materials and Fuels
(Ukrainian State University of Science and Technologies, Dnipro, 2026) Mishalkin, A. P.; Ivashchenko, Valerii P.; Yaroshenko, O. V.; Petrenko, Vitalii O.; Chumak, D. D.
ENG: The scientific and technical relevance of the study lies in determining the directions for improving the ways of using the useful properties of secondary resources in order to intensify the blast furnace process, increase its energy efficiency and reduce pollutant emissions. At the same time, economic efficiency is achieved by reducing the cost of purchasing primary raw materials and reducing waste generation, which corresponds to modern concepts of sustainable development on the way to "green" metallurgy. Purpose of the study. Scientific and practical substantiation of directions for improving the technology of pig iron production through the use of useful properties of secondary resources of raw materials and fuels that have a man-made origin. It is aimed at increasing the level of energy efficiency and improving the slag regime of the blast furnace process, reducing the man-made load on the environment of industrially developed regions of Ukraine. To achieve this goal, the following theoretical and practical tasks will be solved in the study: 1. The analysis of the current state of use of secondary resources of mineral raw materials and fuel in blast furnace production in the conditions of world and domestic metallurgical enterprises has been carried out. 2. The physicochemical properties of the most common types of secondary resources (man-made wastes of metallurgical origin: dust, sludge, scale, production of metallurgical lime: fractions from gas cleaning devices and heat treatment products of waste of plant origin, which are sources of pyrocarbon) have been investigated. Further - determination of the spectrum of their probable purpose, impact on the features and indicators of the blast furnace process, as well as justification of rational ways of their preparation and use. 3. Rational shares of substitution of traditional raw materials and fuels with secondary materials in the blast furnace process are substantiated, the use of which will not reduce the quality of pig iron and will not increase the specific consumption of coke. Their influence on physicochemical and heat-gas-dynamic processes, which is reflected in the characteristic zones of the blast furnace, has been studied. 4. The optimal technological schemes and recommendations for the methods of introduction and rational specific consumption of innovative materials based on man-made wastes have been determined, which will ensure the maximum level of use of their useful properties in the material and thermal balances of the blast furnace process. 5. The technological and environmental advantages of introducing into the blast furnace process a monomaterial, the composition, physicochemical features and spectrum of purpose of which are formed by heat treatment of a mixture of man-made industrial waste, are evaluated and their prospects as a substitute for the corresponding part of pulverized coal fuel (PCF) and fluxes are determined. Research methods. When conducting a comprehensive study, the following methods will be used: - analysis and generalization of materials of scientific and technical literature and patent sources, coordination of their results in accordance with modern trends and the best results of the practice of using secondary resources in blast furnace production; - physicochemical methods of analysis chemical, thermogravimetric, to determine the composition, structure, metallurgical value, probable spectrum of purpose and reactivity of secondary resources of materials - substitutes for iron ore raw materials, coke and pulverized coal fuel (PCF); - thermodynamic forecasting and kinetic modeling of the behavior of experimental materials of secondary origin under the conditions of their heat treatment to assess the influence of their properties on the course of physical and chemical processes and transformations to the thermal and gas-dynamic regime of the blast furnace. The expected results of the study should also include: - development of scientifically grounded recommendations for the effective use of useful properties of the initial potentials of secondary resources of raw materials and fuel in blast furnace production; - establishment of quantitative ratios regarding rational levels of substitution of traditional fuel and raw materials with secondary ones, without reducing the productivity of the furnace and the quality of pig iron while reducing the specific consumption of lime and PCF; - development of a method for the implementation of a complex technological scheme for the preparation, heat treatment of experimental mixtures based on components of mineral raw materials and fuel, followed by the use of an innovative product in the conditions of blast furnace production of pig iron; Scientific novelty of the work. For the first time, systematically, on the basis of the results of an analytical and practical study, the energy efficiency of production and use in the blast furnace process of a two-component monomaterial based on dispersed waste from the production of lime and materials – waste of plant origin, obtained by implementing the effect of their pyrolysis under conditions of joint heat treatment of the initial mixture layer, was substantiated, tested on high-temperature models, poured thermal, in an inclined rotary drum-type furnace. For the first time, a resource-efficient and results-efficient approach has been used to assess the efficiency of the use of materials based on secondary resources of metallurgical and plant origin, based on an integrated combination of the results of thermodynamic forecasting, physical modeling and taking into account the provisions of the exergical methodology for assessing the energy efficiency of the objects of study. Methodological bases have been developed for the selection of rational schemes for the introduction of complex materials based on secondary materials into the blast furnace charge and in the air blast flow to stabilize gas-dynamic conditions in the charge layer, intensify recovery processes with a decrease in the specific consumption of coke per ton of liquid pig iron. The regularities of the influence of the composition and dispersion of secondary resources on the gas-dynamic and thermal parameters of blast furnace smelting have been revealed, which makes it possible to increase the accuracy of predicting the furnace course. It has been proved that the use of materials based on secondary resources of mineral raw materials and fuels can provide the effects of increasing the energy efficiency of pig iron production and reducing the environmental burden, which meets the requirements of sustainable development and the concept of "green metallurgy".
Intelligent Monitoring and Control System for the Pipe Manufacturing Process
(Ukrainian State University of Science and Technologies, Dnipro, 2022) Ivashchenko, Valerii P.; Shvachych, Gennady G.; Sobolenko, Oleksandr; Ivashchenko, Olena V.
ENG: Here one of the new efficient approaches to solving problems of intelligent support of making decisions of a cooperate enterprise scale is analyzed, bearing in mind that the enterprise is oriented towards integration of two interconnected information technologies: a technology of constructing information storages and a technology of intelligent data analysis. A new conception of the role of informating-controlling systems in controlling and operating pipe manufacturing process is suggested. It broadens a traditional view over information systems just as if it were only an instrument of a computer data analysis. The role of the modern information systems in the manufacturing as an independent scientific and applied direction serving as a connecting link in the triad “raw product – ngineering process – end product” is substantiated. Some problems connected with plantation of the informating-controlling systems in the pipe manufacturing is formulated. It broadens a traditional view over information systems just as if it were only an instrument of a computer data analysis.