PURPOSE: To maintain an in-furnace powder rate at a specified value or below and to continue stable operation by eliminating the low-temp. region in a blast furnace shaft part, increasing the utilization rate ηH2 of the gaseous hydrogen at the furnace top and lowering the in-furnace powder rate.
CONSTITUTION: The amt. of scrap to be used is adjusted according to a difference of the stagnation time of the charge in the low-temp. reducing area of 500 to 800°C in-furnace temp. in the blast furnace shaft part or the utilization rate ηH2 of the gaseous hydrogen at the furnace top from a respective reference value, and further, according to a difference of the reduction powdering index RDI value of sintered ore from a reference value, in the operation method alternately charging iron ore and coke into the furnace from the furnace top.
YAMAGUCHI KAZUYOSHI
TAMURA KENJI
