Stepanenko Dmytro Oleksandrovych, Ph.D (Engin.), Senior Researcher, Iron and Steel Institute of Z. I. Nekrasov National Academy of Sciences of Ukraine, Academican Starodubova square, 1, Dnipro, Ukraine, 49107. ORCID: 0000-0002-0184-8295. Е-mail: firstname.lastname@example.org
Togobitskaya Daria Mykolaivna, Dr. Sci. (Engin.), Professor, Iron and Steel Institute of Z. I. Nekrasov National Academy of Sciences of Ukraine, Academican Starodubova square, 1, Dnipro, Ukraine, 49107. ORCID 000-0001-6413-4823
Bielkova Alla Ivanivna, Ph.D (Engin.), Senior Researcher, Iron and Steel Institute of Z. I. Nekrasov National Academy of Sciences of Ukraine, Academican Starodubova square, 1, Dnipro, Ukraine, 49107. ORCID 0000-0001-8519-9351
Цюпа Natalia Oleksandrivna, Ph.D (Engin.), Senior Researcher, Iron and Steel Institute of Z. I. Nekrasov National Academy of Sciences of Ukraine, Academican Starodubova square, 1, Dnipro, Ukraine, 49107. ORCID 0000-0003-0682-461Х
SELECTION OF RATIONAL COMPOSITIONS OF SLAGS AND MIXTURES IN THE PRODUCTION OF IRON AND STEEL
Summary. When solving the problem of choosing the rational chemical composition of metallurgical slags and mixtures, it is important to study their properties (viscosity, melting point, electrical conductivity, surface tension, etc.). According to scientific studies, the physicochemical properties of slag and aluminosilicate melts (including their viscosity and electrical conductivity) depend on the chemical composition of the system and temperature and reflect structural changes in the melt.
The properties of slag melts are well explained by the ion theory according to which the viscosity is determined by the structure of polymer ions (SixOyz- anions), and the electrical conductivity by mobile ions by cations and/or anions (Ca2+, Mg2+, O2-, F–, and etc.). Increasing the temperature of the slag melt weakens the bonds of its structural particles (ions and/or their groups) is an important and necessary condition for improving the efficiency of heat and mass transfer processes in the system “metal-slag”. The study of the relationship between viscosity and electrical conductivity and the development of criteria for assessing the structure of the slag melt, the establishment of a rational chemical composition for specific technological conditions of the smelting process of cast iron or steel is of great scientific and practical importance.
The relationship between the viscosity and electrical conductivity of different oxide systems has been studied and the activation energies of viscosity (Eη) and electrical conductivity (Eχ) have been calculated. A criterion is proposed, the ratio n = Еη/Еχ, which varies in the regions: Еη>Еχ = n >1, Еη<Еχ = n <1 and Еη≈Еχ = n≈1, which indicate the presence of three structural regions: heterogeneous (Еη > Еχ = n> 1), homogeneous (Еη <Еχ = n <1) and equilibrium state of the melt (Еη≈Еχ = n≈1).
The performed research has expanded the scientific ideas about the structure of slag melts, and the proposed criterion allows the choice of rational compositions of slags and mixtures in the production of iron and steel.
Keywords: slag, viscosity, electrical conductivity, model, criterion, structure.
For citation: Stepanenko D.O., Togobytska D.M., Belkova A.I., Tsyupa N.O. Do vyboru ratsionalnykh skladiv shlakiv ta shlakoutvoryuyuchykh sumishey pry vyrobnytstvi chavunu ta stali [Selection of rational compositions of slags and mixtures in the production of iron and steel]. Fundamental’nye i prikladnye problemy černoj metallurgii [Fundamental and applied problems of ferrous metallurgy], 2021, 35, 200-211. (In Ukrainian).
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