| 摘要 |
PROBLEM TO BE SOLVED: To provide a blast furnace operation method that can improve the productivity and reduce the emitted COeven under an operating condition of a pulverized coal ratio of 150 kg/t-p or more.SOLUTION: When the strength of coke charged from blast furnace top is DI[%] 87 or less measured in accordance to a test method described in JISK2151, and at least two of the three conditions that the weight ratio of pulverized coal having particle size of 74 μm or less is 60% or less, the average volatile content of pulverized coal is 25 mass% or less and the blast air temperature is 1100°C or less, are met, the mainstreams of a lance for injecting pulverized coal and a lance for injecting inflammable gas are collided and the injected amount of inflammable gas is maintained at 3 kg/t-p or more, in the blast furnace operation method. When the pulverized coal properties and the blast air temperature are in the same condition and the strength of coke is DI[%] 85 or less, maintain the injected amount of inflammable gas at 10 kg/t-p or more, and when the strength of coke is DI[%] 83 or less, maintain the injected amount of inflammable gas at 20 kg/t-p or more. |
