Model studies on slag metal entrainment in gas-stirred ladles

A synthetic slag is used in ladle metallurgy to capture inclusions in steel to protect the liquid metal from reoxidation and heat losses. The ladles are stirred by gas injection, which creates a two-phase plume of gas and liquid steel that rises to the steel surface. Currently, there is no quantitative link between the entrainment conditions in the system and the rate of refining. Many attempts have been made in the past to characterize this degree of entrainment, most of which are limited to finding the critical condition for onset of entrainment. They found from particle image velocimetry measurements that the velocity difference across the two-phase interface corresponded to the inviscid Kelvin Helmholtz instability criterion. The model was subsequently applied to predict the critical gas injection rate for the onset of entrainment, and reasonable agreement was found between experimental measurements and predictions.