METHOD OF FLUSHING OF BLAST-FURNACE HEARTH Russian patent published in 1999 - IPC

FIELD: ferrous metallurgy, particularly, blast-furnace process; applicable in control of blast-furnace operation. SUBSTANCE: flushing of blast-furnace hearth is carried out with flushing sinter produced from mixture whose iron ore component consists of concentrate (in which iron content is of not less than 65%) and scale with their weight ratio of 1:(1-3), and fluxes in form of mixture of limestone, lime and dolomite. Consumption and composition of flux mixture depends on producing of sinters with basicity (CaO+MgO)/(SiO₂+Al₂O₃)≤ 0.8 and MgO/CaO=0.30-0.50. Flushing sinter is introduced 20-60 times a day for 1-10 days by replacing burden ore components, for instance, pellets, sinters and ore. Ore load is reduced to increase coke consumption for 20-60 kg/t of flushing sinter. EFFECT: increased blast-furnace production efficiency, reduced consumption of coke and improved quality of iron. 2 cl, 3 tbl