Fe-30Ni-5NiO alloy as inert anode for low-temperature aluminum electrolysis

Fe-30Ni-5NiO alloy anodes were prepared by a spark plasma sintering process for aluminum electrolysis. NiO nano-particles with the size of ∼20 nm were dispersed in the anodes. The oxidation behaviors of the anodes were investigated at 800°C and 850°C, respectively. The electrolysis corrosion behaviors were tested in a cryolite-alumina electrolyte at a low temperature of 800°C with anodic current densities of ∼0.5 A/cm². The results indicated that the oxidation kinetic of the anodes followed a parabolic law. A continuous Fe₂O₃ film selectively formed on the surface of the anode during the electrolysis process. A semi-continuous Al₂O₃ layer was observed at oxide film/alloy interface, probably caused by an in-situ chemical dissolution process.