At Kakogawa Works of Kobe Steel, Ltd. a sinter plant and a pelletizing plant have been operated for pretreatment of ores and the ore are used for source of pellets or sinter according to the brand, grain size and chemical composition. This builds an extension to the variety of raw material. In future, as the ratio of fine ore in raw material increases, the importance of pelletizing is considered to increase. Therefore, to establish the predominance of pellets over sinter, advantages of not only cost but also applicability is needed.
From this point of view, test operation was conducted for raising the mixing ratio of pellets from the conventional 35% to 70% at Kakogawa No. 2 blast furnace, where pulverized coal is continuously injected at 120 kg/t. By means of adjustment of burden distribution and mixing small coke into ore, the stable operation was continued with no conspicuous changes in the furnace condition.
