Thermal physics as the basis for energy and resource conservation in steelmaking

Abstract

This article outlines improvements in metallurgical technology achieved on the basis of the integration of thermal physics and information science by the Ural school of specialists in metallurgy and thermal physics. In recent years, mathematical modeling, combined with physical modeling, has significantly reduced the optimization time in the thermal design and debugging of new technologies and equipment. Sintering machines have been modernized by introducing automatic control of the thermal and gas-dynamic processes and by designing new ignition hearths. These measures, besides improving heat and mass transfer, have boosted the performance of sintering plants in Russia and elsewhere, while reducing their environmental impact. In pellet roasting, a refined gas-flow system has been organized, and the gas lines have been reconstructed. As a result, the productivity has increased by 10–17%, with 8–15% decrease in the fuel consumption. The losses of gas after purification have fallen by 50–58%. Roasting machines in Russia, Brazil, and Iran have been reconstructed. In recent years, software has been developed for blast furnaces and introduced at Russia’s largest steelworks: OAO Magnitogorskii Metallurgicheskii Kombinat. In blast furnaces, new air heaters for the blast produce temperatures of 1300°C or more by means of furnace gas and air, without added natural gas. In addition, systems processing metallurgical liquid slag at rates of 3–15 t/min and producing granulated slag at a rate of 0.66–2.0 million t/yr have been built at Russian, Ukrainian, Indian, and Chinese steel plants. A system is also operating successfully at the Norilsk Nickel plant. The thermal conditions in heating furnaces and equipment of various types have been improved on the basis of mathematical simulation of thermophysical processes by means of a dynamic zonal–point model of radiant and complex heat transfer. This method performs well in practice. In recent years, new furnace designs have been developed, and hundreds of heating furnaces have been modernized. Optimal thermal organization has significantly reduced fuel consumption, improved heating of the metal, and resulted in higher quality of the heat-treated product.