| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for operating a blast furnace, in which ferrocoke is used as a blast furnace raw material so that the calorific value of a blast furnace gas generated therefrom can be improved.SOLUTION: The method for operating the blast furnace is characterized in that 25-150 kg/t of the ferrocoke, which has 55-72% of an average value of the reducibility indices JIS-RI and is produced by molding a mixture of a main raw material comprising an iron ore and a sintered ore and a raw material based on coke, coal and the iron ore and dry-distilling an obtained molded product, is charged into the blast furnace from the top of the blast furnace to improve the calorific value of the blast furnace gas generated therefrom. As a result, when the ferrocoke is charged into the blast furnace, the amount of CO to be generated in the blast furnace is increased, the temperature of a heat keeping zone in the blast furnace is lowered, the reducibility of the main material is lowered, and the generated CO is discharged as the blast furnace gas generated therefrom without contributing to reducing action so that the calorific value of the blast furnace gas generated therefrom can be increased. Furthermore, since the temperature of the heat keeping zone in the blast furnace is lowered, a heat loss such as furnace body heat radiation is also lowered to increase the energy efficiency of the blast furnace. |
