OPERATION OF VERTICAL FURNACE USING SINTERED ORE HAVING GOOD CHARACTERISTIC AT HIGH TEMPERATURE

摘要

PROBLEM TO BE SOLVED: To improve the permeability of fused layer formed with sintered ore, to improve the ventilation at the lower part of a blast furnace and to keep the operation of the blast furnace at stable by charging the sintered ore which has good characteristic at high temp. and specifies the average diameter in a specific opening hole diameter, from a furnace top part. ;SOLUTION: The vertical furnace is operated by injecting pulverized fine coal at ≥150 kg/t from a tuyere part of the blast furnace. During this operation, the sintered ore having good characteristic at high temp. and 0.05-0.15 μm average diameter in the opening hole of ≤300 μm is charged from the furnace top in the vertical furnace. This sintered ore having this average diameter is produced by executing one or more of actions among the fine powdery quantity having ≤0.25 mm, powdery coke blending rate, average diameter of the powdery coke, fine powdery coke quantity having ≤0.25 mm and the negative pressure in the operation. As the other way, this sintered ore can be produced by adjusting the basicity in the sintered ore to high and the contents of alumina, silica and magnesia to low.;COPYRIGHT: (C)1999,JPO