JPS55154515A - Desulfurizing method in front of blast furnace - Google Patents

Abstract

PURPOSE:To increase desulfurizing ratio through whole tapping, by making a portion of molten slag flowing together with the preceding tapping molten metal flow into the succeeding tapping molten iron in order to decrease the sulfur content of molten iron tapped in the early stage. CONSTITUTION:In a blast furnace having four tap holes, the first tapped molten metal from the tap hole 1 reaches a ladle 2 through a tapping spout 1, which is equipped with a skimmer 3. Molten slag having followed the molten cast iron is delivered from the skimmer 3 installed on the way to the ladle 2 to a dry pit 6 through a molten slag spout 4. The molten slag spout 4 is equipped with a dividing device 5 at the suitable position, which makes it possible to deliver a portion of the molten slag from the tapping spout 4 into the tapping spout 1' through which the molten metal from a tap hole 2 flows. Upon opening of the tap hole 2 and flowing out of the molten cast iron according to the tap schedule, the dividing device 5 is adjusted simultaneously in order to deliver the molten slag from the tapping spout 1 into the tapping spout 1', whereby the tapped molten metal from the tap hole 2 is accompanied by molten slag from the tap hole 1 even in early stage of the tapping, consequently the desulfurization is promoted.