Transient CFD Modeling of Matte Settling Behavior and Coalescence in an Industrial Copper Flash Smelting Furnace Settler

Copper losses into slag within the flash furnace settler is an economically important topic for the primary copper production. Since the settler is not easily accessible to experimental studies due to harsh reaction conditions, numerical simulations are a promising alternative to obtain more insights into the settling behavior of matte. This study aims to increase the process understanding by developing a CFD flash furnace settler model of an industrial flash furnace. Thereby, the CFD model accounts for bath level changes, polydispersity, and coalescence of matte. Coalescence is modeled by an own empirical model focusing on gravitational coalescence. Matte settling shows size-dependent sedimentation within the slag layer, as supported by an own sampling study. Lowering the slag viscosity by a third decreases the copper loss by approximately 37 pct, while slightly increasing it leads to comparable results. Finally, average copper losses of 0.98 wt pct are estimated, finding good agreement with industrial data.