Multiphysics simulation of slag melting in an induction furnace for sustainable silicon production

Abstract

This work presents a multiphysics mathematical modelling and numerical simulation of the slag melting process in an induction furnace, with a focus on the production of sustainable silicon through the EU SisAl Pilot project. The mathematical model incorporates electromagnetic, thermal and hydrodynamic phenomena in a coupled axisymmetric framework to simulate the melting of a CaO-SiO2 slag, a key component in the aluminothermic reduction process for silicon production. The model addresses the challenge of heating the poorly electrically conductive slag using a graphite crucible and it also accounts for buoyancy-driven convection in the molten slag. The numerical simulations are validated against experimental data from pilot scale trials at Elkem’s plant in Norway. In addition, sensitivity analyses are carried out considering both the progressive filling of the furnace and the inclusion of surface-to-surface radiation models.