IMPROVING THE TECHNOLOGY FOR MAKING STEEL IN OXYGEN-CONVERTER SHOPS

摘要

In recent years, the West Siberian Metallurgical Combine has developed and introduced a series of technological innovations that cut the cost of making steel. The combine mastered a technology for making steel in 160- and 350-ton oxygen converters by using pig iron with reduced silicon and manganese contents. Lowering the concentrations of these elements in the pig makes it possible to minimize its production cost by reducing the unit consumption of coke, increasing blast-furnace productivity, and decreasing the amount of manganese-bearing raw materials used to make the sinter that is employed in the furnace charge. Production of the steel involves preheating scrap inside the converter with the use of TOM- and SSO-grade coals at a rate of 10-22 kg/ton steel. The heat is blown by the "dry" regime (with a highly viscous slag) while the lance is lowered. Slag-formation conditions are improved and the manganese content of the steel is increased by adding manganese sinter containing the following, mass percent: 16-26 Mn_(tot), 20-28 Fe_(tot), 2-4 CaO; 0.9-1.2 MgO; 19-30 SiO_2; 4.0-5.6 Al_2O_3; 0.040-0.047 S; 0.01-0.03 P. The consumption of manganese sinter is 4-12 kg/ton steel. Up to 50 percent of the sinter is added before the preheating of the scrap, and the rest is added during the second half of the blow.