Effect of Converter Shape on Reaction Rate between Slag and Metal in a Combined Blowing Converter with Inert Gas Bottom Blowing

Abstract

The peroxidation of molten steel is a problem occurred in a combined blowing converter with inert gas blowing. It caused by a relatively weak mixing power of bottom blown inert gas compared with that of bottom blown oxygen gas. In order to resolve the problem, several methods for optimizing top and bottom blowing conditions has developed. However, the effect of the equipment condition such as converter shape on the metallurgical characteristics has not been investigated enough. In this study, the effect of H/D (ratio of bath depth H to bath diameter D) on the reaction rate between slag and metal, and furnace body vibration in converter was investigated by water model experiments. It was found that the apparent reaction rate constant, kA/Vw, increase with increasing H/D, except for the case of H/D=0.85. It seemed that the change of kA/Vw with increasing H/D has a relation to the behavior of bath vibration. From the analysis based on the bath surface vibration model, it was indicated that the change of H/D affects the bath surface vibration behavior and the formation behavior of slag emulsion, and these effects increase the reaction interface between slag and metal.