The use of high reactivity coke is proposed to realize low reducing agent rate blast furnace operation. The reducing agent rate was reduced by use of high reactivity coke in an actual blast furnace. The reduction of reducing agent rate is caused by the improvement of the reaction efficiency due to the decrease of the thermal reserve zone temperature. On the other hand, it is suggested that sinter reducibility will affect on the effect of the high reactivity coke. Therefore, in this paper, the quality of high reducibility sinter and the effectiveness of high reactivity coke coexistence of high reducibility sinter were verified by the experimental blast furnace and following results were obtained.
1) The top gas utilization was improved and the reducing agent rate was reduced by use of high reducibility sinter.
2) The permeability was improved by use of high reducibility sinter. The improvement of permeability will be expected in actual blast furnaces.
3)The top gas utilization was improved by use of high reactivity coke. The improvement was caused by the improvement of reaction efficiency due to the decrease of the thermal reserve zone temperature.
4) The degradation of coke was decreased due to the decrease of the amount of reaction.
5) The high reactivity coke works effectively when high reducibility sinter co-exists.