Numerical Investigations on Bubble Behavior at a Steel-Slag Interface

Herein, the volume of fluid (VOF) model is applied to simulate the phenomenon caused by the bubble motion from the molten metal into a slag. First, the mathematical model is validated by the experimental data from the literature. Then, the model is used to quantitatively predict the process of a single argon bubble passage from the liquid steel into the liquid slag. Finally, a parametric study is conducted to determine how the bubble diameter and the interfacial tension influence the bubble movement. The simulation results show that the bubble passing patterns at the steel-slag interface are oscillation-pass, oscillations-breakup, oscillations-pass, pass, and pass-breakup for the 3, 5, 7, 10, and 15 (20) mm bubbles, respectively. For a 5 mm bubble, it is found that an increase in the interfacial tension from 0.04 to 0.8 N m(-1) results in a delayed bubble passage time. The results also show that the bubble experiences an oscillations-breakup process if the interfacial tension value is up to 1.15 N m(-1). However, a higher interfacial tension value (1.8 N m(-1)) can make the bubble pass again but with a longer passage time.