Ilmenite smelters must be operated with the slag bath contained in a freeze lining of solidified slag to prevent refractory damage and ensure feasible furnace life. This makes the process an interesting and challenging one to operate and control. The study focused on interactions between the freeze lining and slag bath. A mathematical model was developed to describe heat transfer, solidification and melting in the freeze lining and furnace wall. This model was incorporated into another model to yield a dynamic simulation-type model of the entire smelting furnace process. Simulation experiments with the models aimed to study the dynamic response of the freeze lining to changes in power input, slag composition, and operating parameters. Due to confidentiality considerations, it was not possible to incorporate industrial data for comparison into the study. Regardless of this, the results still remain useful to practitioners when considering the process aspects that were investigated. (c) 2005 Elsevier Ltd. All rights reserved.