| 摘要 |
PROBLEM TO BE SOLVED: To provide a blast furnace operating method for making ore reduction and permeability in a furnace diameter direction be proper when blowing a hydrogen-containing reducing gas into a blast furnace shaft part.SOLUTION: In a blast furnace operating method, when blowing a hydrogen-containing reducing gas from a blast furnace shaft part, a blowing amount of a hydrogen gas is 20 Nmor more and 150 Nmor less per ton of pig iron, and O/C in a radial direction in a blast furnace top part satisfies the following expressions (1) and (2). The expression (1) is (0.003×VH+1.2)≥a≥(0.003×VH+0.85) and the expression (2) is a≥1.0, provided that: (a) is (O/C)/(O/C), and it is a ratio of O/C of a furnace peripheral part and a furnace intermediate part when the radial direction of the furnace top part is divided into three and defined as 1, 2 and 3 from a furnace center to a furnace wall; and VHis a blowing amount (Nm/tp) of the hydrogen gas. |
