OPERATING METHOD OF BLAST FURNACE FOR PRODUCTION LOW SI PIG

PURPOSE:To obtain stably low Si pig without decreasing the heat level in the lower part of a blast furnace in blast furnace operation by adjusting the basicity distribution of the piled charge layer in the furnace in such a way that the basicity is higher on the side nearer the furnace wall than the central part of the furnace. CONSTITUTION:The component distribution of the charge layer in a blast furnace provided with a mechanism for controlling the charge distribution at the furnace top such as a movable armor or the like is so adjusted as to pile the sintered ore and limestone having higher basicity near the furnace wall and to pile much of sintered ore and silica, etc. having low basicity near the center of the furnace, thereby forming the basicity distribution wherein the raw material layer nearer the furnace wall than the central part of the furnace has higher basicity. Said distribution is so adjusted that the basicity over the entire part has a general level as in the prior art. The stable operating condition of the furnace is maintained without a decrease in slag viscosity and remaining of slag and the low Si pig of about 0.1-0.2% is tapped stably.