Use of converter slags in blast-furnace smelting

The Enakievo Metallurgical Plant is using converter slag as a fluxing component of the charge for its blast furnaces. The contents of the slag are as follows: 44.5% CaO; 17.4% SiO2; 5.97% MgO; 5.06% MnO; 1.24% Al2O3; 14.34% FeO; 8.39% Fe2O3; 19.45% Fetot; 0.118% S and 0.95% P2O5. The use of the processed converter slag in blast-furnace charges in place of raw limestone has made it possible to increase furnace productivity by 178 tons/day and reduce coke consumption by 6 kg/ton pig iron. Despite the fact that use of the converter slag increases the yield of blast-furnace slag, we did not observe any deterioration in the gas permeability of the stock. The desulfurization of the pig obtained in our test was improved by the formation of a basic slag in the hearth of the blast furnace. The performance indices of the furnaces increased in value, while working conditions improved in the slag-processing section. The savings realized from the use of converter slag in blast-furnace smelting amount to 12.4 rubles per ton of slag.