Numerical Investigation of Inclusion Motion at Molten Steel–Liquid Slag Interface During Ruhrstahl Heraeus (RH) Process

Abstract

A CFD and inclusion at interface (IAT) coupled model was built and applied to simulate the floating, collision, and removal of inclusion during the Ruhrstahl Heraeus (RH) process. In the model, the influence of fluid flow, the interfacial properties, the wettability, and the viscosity of each phase are considered. The results show that during the RH process, the inclusion size tends to increase via collisions driven by the flow and buoyancy. The volume fraction of inclusion at certain aggregation points even reaches 10−4 magnitude. The different results of the model with and without the IAT boundary condition (BC) were compared, showing that with IAT BC, more inclusions are blocked by the steel–slag interface, especially the ones with a smaller size. The optimization of the bottom gas blowing rate shows that an excessively small or large blowing rate is hazardous for the inclusion removal.