2019 年 59 巻 7 号 p. 1198-1204
To reduce CO2 emissions from steel works, low reducing agent rate (low coke rate) operation of the blast furnace is desired. Mixing nut coke in the ore layer is one effective measure for realizing this type of operation. Therefore, the effect of coke mixing on the reduction reaction rate of ore and the gasification reaction rate of coke in the mixed layer of ore and coke was investigated. The reduction rate of the ore and the gasification rate of the coke in the mixed layer of ore and coke was estimated by a reduction and gasification experiment, and the packing structure of the coke in the mixed layer was estimated by a mathematical model analysis using the discrete element method. The reduction rate of the ore and the gasification rate of the coke in the mixed layer was affected by the degree of contact between the ore and coke. In addition, the reduction rate of the ore and the gasification rate of the coke in the mixed layer was accelerated by the effects of mutual utilization of the gases generated by the reactions.