DOI: 10.52150/2522-9117-2021-35-200-211

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: d.gorodenskiy@gmail.com

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 (Si_xO_y^z- anions), and the electrical conductivity by mobile ions by cations and/or anions (Ca²⁺, Mg²⁺, O^2-, 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 (E_η) and electrical conductivity (E_χ) have been calculated. A criterion is proposed, the ratio n = Е_η/Е_χ, which varies in the regions: Е_η>Е_χ = n >1, Е_η<Е_χ = n <1 and Е_η≈Е_χ = n≈1, which indicate the presence of three structural regions: heterogeneous (Е_η > Е_χ = n> 1), homogeneous (Е_η <Е_χ = n <1) and equilibrium state of the melt (Е_η≈Е_χ = 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).

DOI: 10.52150/2522-9117-2021-35-200-211

References

1. Mills C., Yuan L., Li Z., Zhang G. (2012). Estimating the electrical & thermal conductivities of slags. Proceedings of 5th International Congress on the Science and Technology of Steelmaking. Dresden, Oct. 1-3. p. 1-10.
2. Zang H. Chou K.C. Measuring and modeling viscosity of CaO-Al₂O₃-SiO₂(K₂O) melt. (2012). Metallurgicals and Materials Transaction B, 2012, 43, 841-848 https://doi.org/10.1007/s11663-012-9668-9
3. Zang H., Yan B.J., Chou K.C., Li F.S. (2011). Relation between viscosity and electrical conductivity of silicate melts. Metallurgicals and Materials Transaction B, 2011, 42, 261-264. https://doi.org/10.1007/s11663-011-9484-7
4. Stepanenko A., Volkova O., Heller H.-P., Otorvin P.I., Chebykin D.A. (2017). Selecting Optimal Slag Conditions in the Blast Furnace. Steel in Translation, 2017, Vol. 47, 9, 610-613. https://doi.org/10.3103/s0967091217090133
5. Frenkel I. (1975). Kineticheskaya teoriya zhidkostej [Kinetic theory of liquids]. Leningrad: Nauka. 1975. 592 [In Rusian].
6. Esin A., Geld P.V. (1966). Fizicheskaya himiya pirometallurgicheskih processov [Physical chemistry of pyrometallurgical processes]. Part 2. Moskva: Metallurgiya. 1966. 704 [In Rusian].
7. Gabdullin G., Takenov T.D., Bajsanov S.O., Buketov E.A. Fiziko-himicheskie svojstva margancevyh shlakov [Physical and chemical properties of manganese slags]. Alma-Ata: Nauka. 1984. 232 [In Rusian].
8. Povolockij Ya., Mishenko V.Ya., Vyatkin G.P. et al. (1970). Fiziko-himicheskie svojstva rasplavov sistemy SaO-Al₂O₃-CaF₂ [Physicochemical properties of melts of the CaO-Al2O3-CaF2 system]. Izvestiya VUZov Chernaya metallurgiya [Izvestiya VUZov Ferrous metallurgy], 1970, 12, 8-11. [In Rusian].
9. PhaseDiagram-Web. Non-interactive diagrams. Retrieved from https://www.crct.polymtl.ca/fact/PDsearch.php.
10. Prihod′ko V., Togobickaya D.N., Hamhotko A.F., Stepanenko D.A. (2013). Prognozirovannie fiziko-himicheskih svojstv oksidnih sistem [Prediction of the physicochemical properties of oxide systems]. Dnepropetrovsk: Porogi. 2013. 339 p. [In Rusian].
11. Prihod′ko V. (1995). Metallohimiya mnogokomponentnyh sistem [Metallochemistry of multicomponent systems]. Moskva: Metallurgiya. 1995. 320 p. [In Rusian].