| 摘要 |
PROBLEM TO BE SOLVED: To secure liquid permeability in a furnace even in the case of increasing the injecting quantity of pulverized fine coal and to provide blast furnace operation having high iron tapping rate by controlling the piling state of the coke charged in a furnace opening part. SOLUTION: The coke layer S2 having a terrace part, in which the piled material surface is formed in flat state, is formed in the range of the distance (r) from the inside of the furnace wall to the shoulder part of the coke layer S2. In the case of adjusting the terrace length (r) to the radius (ro) in the furnace opening part to <=0.27, a gas ventilation and the liquid permeability in the coke layer at the furnace core part are secured, and the molten iron can be produced at a high iron tapping rate even in the case of increasing the injecting quantity of pulverized fine coal. Since the mixed layer S4 formed at the axal center part of the furnace opening part comprises coarse grain coke at a large part therein, a solution loss reaction is restrained and the coke in the coarse grain state, is used to renew the coke layer at the furnace core part.
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