High temperature diffusion processes at the metal/slag interface

The interface metal/molten oxide is of interest for several high temperature processes (metallurgy, gasification…). The exchange reactions occurring at the interface between the metal and the molten slag are complex and up to date not well understood. More generally, this is of importance for the understanding of the exchange reaction kinetics between one metallic compound (solid or liquid) and an ionic one (slag). This work proposes a theoretical approach which takes into account the effect of speciation in the slag on the diffusion process of the species in the two phases and the redox reaction occurring within the vicinity of the interface. The systems investigated consist of Fe and CaO-SiO2 without convection. The concentration profiles of silicon and iron oxide in both parts were calculated. The effect of impurities present in metal phase such as sulphur in the molten slag was investigated. This provides a basis of comprehensive approach for the purification of metal and a better understanding of processes at metal/oxide interface.