| 摘要 |
PROBLEM TO BE SOLVED: To establish a method for stably operating a blast furnace with improved air permeability inside the furnace by preventing reduction powdering of charged raw materials at a blast furnace shaft.SOLUTION: A blast furnace operating method adjusts retention time of charged raw materials passing through a temperature range of 800 to 1000°C when the charged raw material move down by blowing a preheating gas into the blast furnace from its shaft part. The retention time of the charged materials passing through the temperature range of 800 to 1000°C is 60 minutes or more and the 100 Nm3/t or more of heat gas at a temperature of 950°C or more is blown. The charged raw materials is a sinter and/or an iron ore, and a fine coal and/or a reductant are blown from a charging tuyere of the blast furnace. |
