Increase of pulverized coal use efficiency in blast furnace

Abstract

Replacement of metallurgical coke by pulverized coal (PC) injected in blast furnace (BF) tuyeres is a major economical challenge, due to the high price of coke and unfavorable effect of its production for the environment. But the difficulty consists in necessity of complete gasification of coal particles within raceway and compensating for the negative changes in technology. Theoretical and experimental researches of PC burning process under conditions of raceway have been carried out. Methods and designs for intensifying burning have been developed. Among them there are enriching blast with oxygen and its rational use, applying physical methods and chemical additives. Laboratory and industrial tests of these methods have shown the possibility of considerable raise of PC combustion degree under high PC consumption. Effect of coal composition on its use efficiency in BF operation have been examined. Technical and economical parameters of BF operation when injecting PC from different coals have been calculated. Recommendations to coal grinding and method of complex compensating for the changes in technological regime have been developed.