BLAST-FURNACE SMELTING METHOD Russian patent published in 2002 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: method involves charging iron ore material and coke into blast furnace; blowing fuel additive into fuel-injection tuyere; charging lumpy schungite into annular zone of furnace mouth arranged within the range restricted by radii of 0.1- 0.95 of mouth radius; mixing schungite with coke; changing position and length of said annular zone for stabilizing silicon content in cast iron. For increasing silicon content in cast iron by 0.1%, said annular zone is moved to furnace center to increase its area by 10-20% through reducing radius of inner boundary of said annular zone. For reducing silicon content in cast iron by 0.1%, said annular zone is moved to peripheral part of furnace to increase its area by 10-20% through increasing radius of outer boundary of said zone. Method is used for manufacture of conversion pig iron and cast iron and ferrite alloys in blast furnaces equipped with feeding devices allowing distribution of charged materials in radial direction of furnace mouth to be controlled within wide range. EFFECT: increased efficiency of blast furnace, reduced consumption of coke and improved quality of cast iron. 1 ex