Abstract
In the production of steel, as the productivity rises and the resource and energy consumption declines, improvements in converter design are required to ensure preliminary scrap and batch heating and to intensify redox processes in the liquid bath and exhaust-gas combustion above the bath, without impairing the durability of the injection systems and the converter lining. The use of fuel–oxygen combustion flames in the converter resolves numerous technological problems. The hydrodynamics in the reaction zones and in the liquid bath may be greatly changed by fuel combustion in the converter’s working space with jet formation or by means of submersible combustion flames. In the present work, thermodynamic methods are used to analyze the dynamics of gaseous-fuel combustion and the oxidation of elements in the converter bath on interaction with high-temperature combustion products. The interaction of the combustion flame and chemical elements in the converter bath is calculated for equilibrium conditions. The use of the combustion flames is found to change the composition of the gas phase in the converter’s working space (above the bath), which contains H2 and H2O in addition to the traditional components associated with oxygen injection: O2, CO, CO2. The presence of H2 and H2O changes the thermal conditions and oxidative properties of the gas phase. In the combustion of gas–oxygen fuel, the optimal composition of the initial gas mixture (natural gas + oxygen) must correspond to the ratio 100% CH4 + 69% O2. The oxidation product is gaseous phase consisting of 40% CO2 + 60% H2O. The total enthalpy of combustion of the gas–oxygen fuel at converter temperatures, with an oxygen excess greater than 1.0 (up to 2.0), is about 200 kJ per mole of the initial reagents. In the oxidation of methane by carbon dioxide, the total enthalpy of combustion is between–7 and–14.5 kJ/mol of initial reagents at 1800 K. The process becomes endothermal at temperatures above 2000 K: ΔH 2200 = 7.7–15.4 kJ/mol. In the oxidation of natural gas by water vapor, ΔH 1800–2200 = 19.5–70 kJ/mol. Thus, flame temperatures above 1800 K may only be attained in the oxidation of methane by oxygen. The use of air, carbon dioxide, or water vapor as the oxidant does not yield the required thermal effect.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Shneerov, Ya.A., Smoktii, V.V., Shor, V.I., Afonin, S.Z., and Leporskii, S.V., Combined processes of steel smelting in oxygen converters: an overview, Chern. Metall., Ser. Staleplavil’noe Proizvod., 1982, vol. 4, p. 23.
Hosoki, S., Production technology of iron and steel in Japan during 1992, ISIJ Int., 1993, vol. 33, no. 4, pp. 427–445.
Osani, H. and Ohmiya, S., Total hot metals pretreatment and BOF operation practice for high purity steelmaking, 1st European Oxygen Steelmaking Congr., Düsseldorf, 1993, pp. 41–46.
Krieger, W., Proferl, G., and Pochmarskital, L., Metallurgische und Betriebliche Ergebisse des LD-processes bei Zufur von Inerigasen durch den Tiegelboden, Berg-Huettenmaenn. Monatsh., 1983, no. 9, pp. 332–338.
Haastert, H.P. and Hoffken, E., Konverterstahlwerke kombiniertes blasen und das TBM-verfahren in den Stahlwerken der Thyssen, Stahl Agll Thyssen Tech. Ber., 1985, no. 1, pp. 1–10.
Jacobs, H., Q-BOP process–after eleven years, Metals, 1973, vol. 25, no. 3, pp. 33–41.
Afonin, S.Z., Vyatkin, Yu.F., and Yugov, P.I., Increasing the efficiency of converter steel production by introducing combined blow-down and dynamic process control systems, Stal’, 1986, no. 10, pp. 5–7.
Kitamura, M. and Hoh, S., LD-converter way of combined blowing, Kobe Steel Eng. Rep., 1982, vol. 32, no. 4, pp. 85–87.
Mink, P., van Unen, G., and Deo, B., Developments in bath agitation process at Hoogovens, IJmuiden, 1st European Oxygen Steelmaking Congr., Düsseldorf, 1993, pp. 65–70.
Fedorovich, V.G. and Karp, S.F., Combined blowing of high-phosphoric iron in a laboratory converter, Izv. Vyssh. Uchebn. Zaved., Chern. Metall., 1960, no. 8, pp. 34–37.
Ohnishi, M., Nagai, J., Yamamoto, T., et al., Metallurgical characteristics and operation of oxygen top and bottom blowing at Mizushima Works, Ironmaking Steelmaking, 1983, vol. 10, no. 8, pp. 28–34.
Jacobs, H., Ceschin, B., Dauby, D., and Claes, J., Development and application of the LD–NC top and bottom blowing process, Iron Steel Eng., 1981, vol. 58, no. 12, pp. 39–43.
Bogdandy, L., Von Brotzmann, K., and Fritz, E., Improvements in bottom blowing by combined blowing technique and increase of the scrap rate, Iron Steel Eng., 1981, no. 9, pp. 58.
Chernyatevich, A.G., Protopopov, E.V., and Ganzer, L.A., On some peculiarities of oxidation of impurities in the converter bath with combined blowing, Izv. Vyssh. Uchebn. Zaved., Chern. Metall., 1987, no. 4, pp. 25–29.
Protopopov, E.V., Chernyatevich, A.G., and Yudin, S.V., Hydrodynamic features of converter bath behavior at various blowdown methods, Izv. Vyssh. Uchebn. Zaved., Chern. Metall., 1998, no. 8, pp. 23–29.
Chernyatevich, A.G., Brodskii, A.S., and Panteikov, S.P., High-temperature modeling of converter bath behavior at combined oxygen blowing, Izv. Vyssh. Uchebn. Zaved., Chern. Metall., 1997, no. 12, pp. 27–31.
Protopopov, E.V., Aizatulov, R.S., Ganzer, L.A., Kalashnikov, S.N., and Verevkin, G.I., Applied study of liquid motion in zone of blowing by jets with different dynamic head, Izv. Vyssh. Uchebn. Zaved., Chern. Metall., 1996, no. 6, pp. 18–23.
Trubavin, V.I., Prosvirin, K.S., Shchedrin, G.A., et al., Features of structure and hydrodynamics of reaction zone at bottom blowing of converter bath by oxygen and oxygen-fuel jets, Metall. Koksokhim., 1979, no. 63, pp. 26–29.
Yakushevich, N.F., Strokina, I.V., and Polyakh, O.A., Determining redox parameters in the Fe–C–O2–H2 system, Steel Transl., 2011, vol. 41, no. 8, pp. 631–635.
Suris, A.L., Termodinamika vysokotemperaturnykh protsessov: spravochnik (Thermodynamics of High-Temperature Processes: Handbook), Moscow: Metallurgiya, 1985.
Elliott, J.F., Gleiser, M., and Ramakrishna, V., Thermochemistry for Steelmaking, Reading, Mass: Addison- Wesley, 1963.
Termodinamicheskie svoistva individual’nykh veshchestv (Thermodynamic Properties of Individual Substances), Glushko, V.P., Ed., Moscow: Nauka, 1979.
Tolstoguzov, N.V., Teoreticheskie osnovy i tekhnologiya plavki kremnistykh i margantsevykh splavov (Melting Theory and Technology of Siliceous and Manganese Alloys), Moscow: Metallurgiya, 1992.
Turkdogan, E.T., Physical Chemistry of High Temperature Technology, San Diego: Academic, 1980.
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © V.V. Solonenko, E.V. Protopopov, S.V. Feiler, N.F. Yakushevich, 2017, published in Izvestiya Vysshikh Uchebnykh Zavedenii, Chernaya Metallurgiya, 2017, No. 7, pp. 556–564.
About this article
Cite this article
Solonenko, V.V., Protopopov, E.V., Feiler, S.V. et al. Oxidation of molten impurities in converters by means of combustion flames: Thermodynamic principles. 1. Thermodynamic analysis of processes in natural-gas combustion. Steel Transl. 47, 449–455 (2017). https://doi.org/10.3103/S0967091217070130
Received:
Published:
Issue Date:
DOI: https://doi.org/10.3103/S0967091217070130