Effect of gas bubbling and impeller agitation on degassing kinetics during magnesium alloy (AZ91D) melt recycling - Water model approach

Abstract

A water model approach was carried out to simulate degassing kinetics in metallurgical refining vessel for the recycling of magnesium-based alloy (AZ91D). In order to investigate the behavior of hydrogen gas in magnesium alloy melt, oxygen/water system was adopted to simulate degassing process in water by air bubbling together with impeller agitation. It was found that increased surface area by the formation of dispersed fine bubbles was found to be very effective for degassing. For comparisons, the surface area of air bubbles and mass transfer coefficients of oxygen in water were theoretically calculated and compared with water model experiments. It matched well each other.