Formation of Fine Bubble through Swirling Motion of Liquid Metal in the Metallurgical Container

Abstract

In pyrometallurgical processes, creation of gas-dispersed metal system is required to promote an interfacial reaction rate at a gas-liquid metal boundary, as well as to remove non-metallic inclusions in a bulk metal. We found that fine gas bubbles penetrated easily from a container wall to a mercury bath by addition of the swirling motion which created a centrifugal force. Measured radius of bubbles in a metal bath, B is in good accordance with that calculated by the following equation; B=(1/2)^1/3 (1/w)(2Rσ/ρ)^1/2: w ; tangential velocity, R; radius of container, σ; surface tension of molten steel, ρ; density of molten steel. In the system, injection pressure for penetration of bubbles in the metal bath is much lower than that of conventional injection process by tuyeres and lances.