The use of freeze linings to protect pyrometallurgical furnaces from chemically corrosive molten slags is a widespread technique in industrial processes. The main goal of the present study is to establish a modeling framework that considers fluid flow, heat transfer, and slag solidification to simulate freeze-lining formation and its dependency on operating conditions. A mixture continuum solidification model, which had been used for the solidification of metal alloys, was employed. Several parametric studies have been conducted to better understand the smelting process. The results demonstrate that the model can capture freeze-lining formation and predict the global energy balance and flow behavior of the smelting furnace. The freeze-lining thickness was shown to depend on heat removal intensity during the process and slag bath chemistry. A direct relationship between the average temperature in the refractory and freeze-lining thickness was also observed. This is an important indicator for furnace operators in controlling the furnace operation parameters. This improved knowledge offers the potential to further optimize furnace operations and reduce energy costs and environmental impacts. A discussion was presented on the different modeling assumptions considered and potential future model refinements.