Effect of metallic phase species on the corrosion resistance of 17M/(10NiO-NiFe₂O₄) cermet inert anode of aluminum electrolysis

Abstract

NiFe₂O₄-based cermet inert anodes with metallic phase compositions of Cu, Ni and 85Cu15Ni were prepared by cold pressing-sintering. Their corrosion resistance was also investigated in Na₃AlF₆-Al₂O₃ melts. The results show that the metallic phase species in cermets have no effect on the concentration of impurities in bath during electrolysis, the total steady-state concentration of impurities is almost the same, i. e. between 4.12×10⁻⁴−4.80×10⁻⁴. There exists metal preferential corrosion for the cermet inert anode with metal Ni as metallic phase. For NiFe₂O₄-based cermets, the cermet with metal Cu as metallic phase exhibits better corrosion resistance than the others.

Keywords

inert anode / NiFe₂O₄ based cermet / metallic phase species / corrosion resistance