OPERATING METHOD OF BLAST FURNACE BY WHICH POWDER IS BLOWN THROUGH TUYERE

PURPOSE:To maintain the uniform characteristics of molten irons and to meet the requirement for small-volume production of diversified kinds with a method for blowing various kinds of powders through each tuyere into a blast furnace by controlling the blowing of the powder according to the characteristic of the molten metal from each tap hole. CONSTITUTION:The characteristics, such as the temp. and components, of the molten iron to be tapped from each tap hole are measured with a method for operating a blast furnace provided with plural tap holes in the circumferential direction thereof while blowing various kinds of powders through each tuyere into the furnace. The kind and amt. of powder to be blown through the tuyeres in the range having relation corresponding to the respective tap holes are controlled according to the results of the measurement so that the molten metal to be tapped from each tap hole have uniform characteristics. Or the kind and amt. of the powder to be blown through the tuyere within the range having the relation corresponding to the specific tap hole are preliminarily controlled so that the molten iron having the required characteristics can be tapped from the specific tap hole according to the results of the above-described measurement.