BLAST FURNACE OPERATION METHOD

PROBLEM TO BE SOLVED: To provide a blast furnace operation method, in the case dust coals with different descriptions are blown from different lances, capable of efficiently increasing the burning rate of the whole of the dust coals to be blown.SOLUTION: The descriptions and blowing quantity of the dust coals blown from lances 4 are decided in advance, and the increasing slant of the dust coal burning rate to the increasing quantity of the blowing quantity of the oxygen to be blown is obtained in advance. In the case the increasing slant of the dust coal burning rate to the increasing quality of the oxygen to be blown has been known per description and blowing quantity of the dust coal, the burning rate of the whole of the dust coals in accordance with the oxygen blowing quantity from each lance 4 can be found from the weighted average burning rate of the dust coal blowing quantity. At this time, when the blowing quantity of the oxygen blown from each lance 4 is increased in the high order of the increasing slant of the burning rate of the dust coal blown from all the lances 4, the burning rate of the whole of the dust coals is most efficiently increased. For obtaining the maximum efficiency burning rate, the blowing quantity of the oxygen blown from each lance 4 is set in accordance with the description and blowing quantity of the dust coals blown from all the lances 4.