JPS5794509A - Method for addition of aditive to molten iron - Google Patents

Abstract

PURPOSE:To perform mixing and reaction of additives and molten steel uniformly and quickly by adding the additives into the iron notch just prior to tapping at the stage of tapping molten iron from a blast furnace. CONSTITUTION:In tapping molten iron 5 from a blast furnace, preliminary refining outside the furnace is carried out prior to entering a steel making furnace by adding additives such as a desulfurizer, a desiliconizer, a dephosphorizer, and the like. At the time when the molten steel 5 and molten slag 6 are tapped into a tapping spout 3 by passing through the iron notch 2 of the blast furnace, the wire like additives 10 packed in a metallic pipe of mild steel or the like are inserted consinuously into the notch 2 before the molten metal ejecting flow 9 which the molten metal drops through the notch 2 into the spout 3. The pipe made of mild steel melts and the additives therein mix uniformly with the molten iron in an ejecting part 9, whereby preliminary refining such as desulfurizing, desiliconizing, and dephosphorizing are carried out. The molten slag formed at this time is separated together with the molten slage 6 of the blast furnace by a skimmer 4 provided to the spout 3, whereby it is separted into a molten spout 8 and a molten slag spout 7, respectively.