| 摘要 |
PROBLEM TO BE SOLVED: To provide a blast furnace operation method in which variability of tuyere tip temperature in a blast furnace circumferential direction can be suppressed.SOLUTION: A lance 4 that blows dust coal and oxygen in hot blast blasted to each tuyere 3 from different blow channels is included, when dust coal and oxygen are simultaneously blown from the lance 4 to the tuyere 3 of a blast furnace 1, a blow amount of dust coal is measured for each tuyere 3, a measured value of a blow amount of measured dust coal is used, and a blow amount of oxygen blown from the lance 4 is set for corresponding each tuyere 3. Thereby, variability of tuyere tip temperature in a blast furnace circumferential direction can be suppressed, thereby burning of dust coal is stabilized, variability of depressant speed of a charging material in a circumferential direction is made not to exist, air permeability of furnace gas becomes favorable, thereby reduction efficiency is raised, heat loss from a furnace wall is lowered, thereby stable low reduction material ratio operation can be realized, and tap temperature is stabilized, thereby an effect in which molten iron quality is stabilized can be also obtained. The effect is remarkable in a dust coal ratio of at least 150 kg/t-hot pig iron. |
