METHOD FOR OPERATING BLAST FURNACE BY INJECTING LARGE-QUANTITY OF FINE-POWDERY COALS

摘要

PROBLEM TO BE SOLVED: To provide a method for operating a blast furnace by injecting a large quantity of fine powdery coals in which, even in the case of injecting a large quantity of fine powdery coals, the formation of "bird's nest" is suppressed by a simple method to achieve excellent air permeability at the lower part in the furnace, thereby obtaining the stable blast furnace operation.;SOLUTION: The method for operating the blast furnace, in which the fine powdery coals of ≥180 kg/ton of molten iron are injected into the blast furnace by using a lance for injecting the fine powdery coals inserted so as to bore through the peripheral wall of a blowing pipe connectively arranged on the front side of a tuyere of the blast furnace is characterized in that a large quantity of fine powdery coals is injected into the furnace by inserting a nozzle for blowing oxygen-enriched gas or pure oxygen by boring through the peripheral wall of the blowing pipe as well as the lance for injecting the fine powdery coals and jetting the oxygen-enriched gas or the pure oxygen jet from the nozzle for blowing the oxygen-enriched gas or the pure oxygen at the speed of ≥1.5 times the flowing speed of hot blast blasted into the furnace from the blowing pipe at the tip-end part of the tuyere.;COPYRIGHT: (C)2011,JPO&INPIT