A CONSIDERATION ON THE EFFICIENCY OF BLAST FURNACES

Abstract

The reduction of iron in the iron blast furnaces may be regarded to be due to both of C and CO. The reduction amount due to CO gas amounts to 60 70% of the total iron content, and the rest is due to the direct reduction of carbon. The amount of coke used in the direct reduction corresponds to 10-15% of the total consumption and its rate is called the direct reduction percentage "D.R%". The magnitude of D.R% is represented by the combustion velocity of coke and the charging velocity. The production capacity of a blast furnace is mostly determined by the direct reduction pereentage, the gas reduction percentage and the blast quantity. It is possible to presume the highest capacity of the furnace by defining the limit value of the aforementioned three. Espeoially the magnitude of D.R% greatly influences the furnace status and the produetion capacity. The author theoretically explained that D.R% varys with the preheating capacity of the blast stove and the quantity of materials used, and thus intellded to contribute to the operation of a blast furnace.