A Finite Element Method Approach to the Design Process of an Aluminium Reduction Cell

摘要

An aluminium smelter produces aluminium through electrolysis in reduction cells. A high DC-current is passed from an anode to a cathode, through a highly resistive cryolite bath and a low resistance liquid metal pad. The magnetic flux density and current gives rise to Lorentz forces inside the liquid aluminium, which produce waves at the interface between the bath and the liquid metal. These waves can grow large enough to impact the current paths and therefore disturb the current density distribution in the reduction cell. This may cause the cell to become unstable, leading to a loss in current efficiency, reduced cell life/total cell failure. In reduction cells, similar to the one shown in Figure 1, the instability is mainly caused by the vertical component of the magnetic flux density BZ and this is a significant factor in cell design [1].