MANUFACTURE OF SINTERED IRON ORE HAVING IMPROVED REDUCTION POWDERING PROPERTY AT LOW TEMPERATURE

摘要

PURPOSE:To improve the reduction powdering properties of sintered iron ore at low temp. by setting a period of time for which a nonoxidizing gas or a weakly oxidizing gas is fed after a combustion zone reaches the lowest layer and before sintered ore is discharged from a grate. CONSTITUTION:Iron ore is charged onto a grate to form a starting material layer for sintering, the surface of the layer is ignited while feeding air downward, and the combustion zone is allowed to reach the lowest layer. The resulting sintered ore is discharged from the grate. After the sintering and before the discharge, a period of time for which a nonoxidizing gas or a weakly oxidizing gas is fed is set. Gaseous N2 is used as the nonoxidizing gas, and a gaseous mixture of =50vol% N2 with air is used as the weakly oxidizing gas.