2009 Volume 95 Issue 12 Pages 813-820
Usage of highly reactive coke in order to decrease thermal reserve zone temperature in blast furnace is considered promising to increase reaction efficiency in blast furnace and to decrease reducing agent rate. We focused attention on the catalytic effect of iron and succeeded in producing highly reactive formed iron coke with high iron content. In this paper the reaction behavior of formed iron coke when mixed with conventional coke and in the presence of alkali was investigated and the following results were obtained. It was shown that when the mixture of iron coke and conventional coke is heated in a reaction gas, iron coke selectively and preferentially reacts near the thermal reserve zone temperature (900°C), which causes a decrease in thermal reserve zone temperature, while conventional coke reacts little and is protected from degradation. It was also confirmed that catalytic activity of Fe and that of K is independent each other and that in the presence of alkali, the reaction beginning temperature of iron coke is lower than that of conventional coke. These results show that the use of formed iron coke could decrease thermal reserve zone temperature in an actual blast furnace where coke reactivity is promoted by condensed alkali vapor.