On the Prediction of the Crust Evolution inside Aluminum Electrolysis Cells

A model for predicting the evolution of the crust inside aluminum electrolysis cells is presented. The model takes into account the effects of heat transfer, solid/liquid phase-change, and chemical transformation of anode covering material (ACM). The model predicts: 1) the temperature field inside the cell, 2) the evolution of the ACM conversion into crust, 3) the melting/solidification processes inside the cell and, 4) the time-varying heat losses at the top of the cell. The model is validated with experimental data taken on an industrial electrolysis cell. Results show that the model captures the essential behavioral features of the industrial cell. However, further experiments must be performed in order to provide reliable data on the crust formation. These experimental data are needed for a thorough validation of the mathematical model.