Reconsideration of the Relationship between Coke Quality and Blast Furnace Performance

The contradiction between constantly pursuing higher coke thermal strength and shortage of coking coal resources has been aggravated, directly threatening the sustainable development and survival of blast furnace technology. Discussions were made from the viewpoint of metallurgical reaction engineering on the issue of coke quality. Because the reduction of wustite and the gasification of coke are a pair of coupled reactions, the amount of gasified coke in the blast furnace is essentially determined by the reducibility of coke. As highly reducible iron ores are used, the increase in coke reactivity is favorable to the improvement of blast furnace efficiency. Experimental studies have demonstrated that the governing factor is the regular multi-phase counter-current movement in the lower blast furnace, and the permeability of gas and liquid in the coke bed could be improved and furnace smooth running could be promoted by means of increasing the resistance against size degradation. A proposal was put forward that multi-discipline investigations of ironmaking, cokemaking and coal geology should be carried out to formulate new coke quality standards.