Reaction behavior of caloaded highly reactive coke

Abstract

Usage of highly reactive coke in order to decrease the thermal reserve zone temperature in a blast furnace is considered promising to increase the reaction efficiency in the blast furnace and to decrease the reducing agent rate. In order to develop a new method to produce highly reactive coke by adding a Ca catalyst other than Ca-rich coal, in this paper, firstly the effects of Ca compounds pre-addition to coal on coke qualities were investigated. It was shown that carbonizing the mixture of coal and Ca compounds (CaO, CaCO3) greatly increased coke reactivity and that it was possible to produce Ca-loaded highly reactive coke with high coke strength by adding 3% of Ca compounds under such conditions as high strength coke was produced. Furthermore, the reaction behavior of Ca-loaded highly reactive coke when mixed with conventional coke in the presence of an alkali was investigated. It was shown that when a mixture of Ca-loaded highly reactive coke and conventional coke was heated in a reaction gas, Ca-loaded coke selectively and preferentially reacted. It was also confirmed that Ca acted as catalyst in the existence of K. This shows that the reactivity of Ca-loaded coke is higher than that of conventional coke in an actual blast furnace whereby coke reactivity is promoted by condensed alkali vapor.