Alumina dissolution modeling in aluminium electrolysis cell considering MHD driven convection and thermal impact

Abstract

In the last decade, the cell productivity has been dramatically improved as demonstrated on AP30 technology with amperage increase from 350 kA to 440 kA. At the same time, available liquid bath volume in the pots has been drastically reduced by the anode surface enlargement. In order to achieve such impressive step change, management of alumina dissolution is a key point to optimize both cell design and process control algorithms. Rio Tinto Aluminium and EPFL have developed a 3D model taking into account the cell geometry, metal and bath velocities, alumina granulometry and thermal balance. It enables to optimize number, location and feeding rate of point feeding systems. In this paper, we present the model development, the latest progress and the model validation with measurements performed on AP technology pots.