METHOD FOR OPERATING BLAST FURNACE

摘要

Provided is a method for operating a blast furnace with which it is possible to further increase the combustion temperature and reduce the amount of reducing material required per basic unit. A solid reducing material and a flammable reducing material are mixed and blown in from a single tube that constitutes a lance (4). For example, a solid reducing material and a flammable reducing material are mixed, and the reducing-material mixture is blown in from a single-tube lance (4). Alternatively, the lance is structured as a double-tube lance (4), a reducing-material mixture obtained by mixing a solid reducing material and a flammable reducing material is blown in from the inner tube of the double-tube lance (4), and a combustion-supporting gas is blown in from the outer tube of the double-tube lance. Alternatively, the lance is structured as a double-tube lance (4), a combustion-supporting gas is blown in from the inner tube of the double-tube lance (4), and a reducing-material mixture obtained by mixing a solid reducing material and a flammable reducing material is blown in from the outer tube of the double-tube lance. Pulverized coal is mainly used as the solid reducing material. City gas, revolving-furnace gas, blast-furnace gas, coke-oven gas, or hydrogen is used as the flammable reducing material. O2 is used as the combustion-supporting gas.