METHOD OF PERFORMING BLAST-FURNACE SMELTING Russian patent published in 2003 - IPC

FIELD: ferrous metallurgy; blast-furnace processes; control of flow rate of additional fuel blown into blast furnace hearth. SUBSTANCE: proposed method includes loading charge and coke into blast furnace, putting-on oxygen-enriched and moistened hot blast, gaseous fuel in form of natural of coke gas, check of composition and amount of charge materials and coke, chemical composition of coke-oven gas and check of flow rate of gaseous fuel and blast. Flow rate of gaseous fuel and content of oxygen in blast are found from the following formula: a(6,1•v²-38,12•v+70,15), ω + 21 + b U, where U is flow rate of gaseous fuel being blown, for example natural gas or coke gas, % of dry blast; v is coefficient showing specific yield of gases (CO + H₂) at incomplete chemical combustion of gaseous fuel (cu m/ cu m); ω is content of oxygen in blast, % of dry blast; a, b are coefficients showing thermal and physico-chemical properties of blastfurnace charge: a = (0.70-1.20) and b = (0.30-0.50). EFFECT: reduced power requirements; improved quality of cast iron. 2 tbl, 5 ex