9th International Conference on Modeling and Simulation of Metallurgical Processes in Steelmaking - STEELSIM2021

As an essential stage in inclusion removal processes, separation of inclusion at the steel-slag interface certainly affects the overall removal efficiency and is of great importance to molten steel cleanliness. In this study, the dynamics of a spherical Al2O3 inclusion (50 μm in diameter and with a typical contact angle of 45°) interacting with the steel-slag interface is investigated using computational fluid dynamics. We employed the volume of fluid (VOF) method in combination with the dynamic overset grid technique to account for particle motion near the steel-slag interface. This numerical approach is capable of capturing the meniscus in the course of particle motion and incorporating the Marangoni flow induced by particle dissolution. The results demonstrate that the capillary force arising from the formation and continuous evolution of a meniscus is mainly responsible for inclusion motion. In consequence, the spherical inclusion generally accelerates to a quite high velocity, then undergoes a deceleration stage, and finally settles in an equilibrium position at the interface in a very short time. Based on the case of rapidly trapped inclusion, the subsequent dissolution drives a flow along the interface. Eventually, this interfacial flow can further lift the inclusion up to a certain distance, which could facilitate the separation process. This study provides an understanding about the physics of inclusion removal which is essential for steel quality control.