METHOD OF FORMING PROTECTIVE SKULL ON BLAST FURNACE HEARTH LINING Russian patent published in 2004 - IPC

FIELD: ferrous metallurgy; blast furnace processes; melting cast iron in blast furnaces. SUBSTANCE: proposed method includes introduction of skull-forming additive into burden of blast furnace in form of lumpy shungite at size of 10-100 mm containing 28-32% of carbon and 58-60% of silica. Skull-forming additive is fed according to results of monitoring lining temperature at level of joint of hearth and blast-furnace bottom. At positive deviation of temperature trend from preset level by more than 10 C, shungite in the amount of 2.0-6.0% of mass of coke is loaded into narrow peripheral ring bounded by radii of 0.8-1.0 of furnace to radius. For local protection of hearth lining, its temperature is monitored by sectors for finding the sector at maximum temperature; at deviation of this temperature by more than 15 C from average temperature over circumference, shungite is periodically loaded into furnace top sector located above hearth sector at maximum lining temperature by batches of 0.10-0.25 of portion of iron ore portion of burden. EFFECT: enhanced efficiency of forming skull on furnace walls. 3 cl, 2 ex