| 摘要 |
PROBLEM TO BE SOLVED: To provide a blast furnace operation method capable of enhancing productivity and reducing exhaust COeven under an operation condition with fine coal ratio of 150 kg/t-p or more.SOLUTION: Concentrations of combustion-sustaining gas and easily combustion gas blown together with fine coal as gas concentrations in a lance are 50 to 80 vol% and 10 to 40 vol% respectively by blowing the combustion-sustaining gas and the easily combustion gas together with the fine coal from the lance, when strength of coke injected from a furnace top by a test method described in JISK 2151 DI[%] is over 83 and 85 or less and at least two or more of 3 conditions: weight percentage of fine coal with particle diameter of 74 μm or less of 60% or less, average volatile content of fine coal of 25 mass% or less and blowing temperature of 1100°C or less are satisfied.SELECTED DRAWING: Figure 1 |
