Computational Modeling of Thermochemical Evolution of Aluminum Smelter Crust

Abstract

In an aluminum reduction cell, crushed anode cover at room temperature is added onto the exposed bulk electrolyte surface around newly positioned anodes and is heated by high heat flux from this liquid electrolyte. Liquid electrolyte penetrates inside the porous anode cover. Solid cryolite and alumina crystallize from the liquid electrolyte due to the temperature gradient in the anode cover. A solidified crust forms at the bottom part of the anode cover during the heating up period. A thermochemical model which takes into account both the liquid electrolyte penetration and phase transformations has been developed to simulate the temperature evolution, chemical composition development, and liquid front penetration and content in the anode cover. The model is tested against experimental data obtained from industrial cells and laboratory experiments in this paper.