Mitigating Cathode Corrosion in Aluminum Reduction Cells Using a VOF-Electric Model

The corrosion of carbon cathodes in aluminum reduction cells operating at about 950°C significantly impacts the cells’ lifespan. This issue is exacerbated when graphitized cathodes are used. In this paper, a volume-of-fluid electric (VOF) model was developed to investigate the evolution of corrosion in graphitized cathodes and explore the influence of sludge and different cathode materials on corrosion. Cathode corrosion (CC) initiates at the ledge toes and spreads to the central channel. The maximum corrosion depth for graphitized cathodes reaches − 0.2 m at the ledge toes after 2100 days. The presence of a solid ledge effectively protects the cathode underneath. When sludge is introduced, it alters the local electric current density (ECD) distribution without significantly affecting the overall pattern. Sludge in the central channel protects the cathode beneath but slightly intensifies corrosion at the ledge toes, with a maximum corrosion depth of − 0.203 m, which reduces to − 0.196 m with sludge placed in the side channel. Transitioning to a semi-graphite cathode material reduces the maximum ECD at the ledge toes, resulting in a reduced maximum corrosion depth of − 0.187 m. This research provides valuable insights into the development of cathode corrosion in graphitized cathodes, highlighting the importance of cathode material selection.