BLAST FURNACE OPERATION METHOD

摘要

Provided is a blast furnace operation method enabling additional increase in combustion temperature and a decrease in the basic unit of reducing agents. Pulverized coal (PC: solid reducing agent), city gas (flammable reducing agent), and O2 (combustion-supporting gas) are blown, one type after another, independently, and in all types, into each of an inner tube lance, an intermediate tube lance, and an outer tube lance constituting a three-fold tube lance. Initially, the city gas burns with O2, for example, whereby the pulverized coal is explosively diffused while the temperature of the pulverized coal is significantly increased due to the heat of combustion of the city gas. This leads to an increase in heating velocity of the pulverized coal and a significant increase in combustion temperature, which enables a decrease in the basic unit of the reducing agents. Some of enriching O2 is blown through the three-fold tube lance for blasting so that oversupply of O2 can be avoided without adversely affecting the gas balance in the blast furnace, and the basic unit of the O2 used can be decreased.