A 100 mm diameter cup-shaped inert anode for aluminum electrolysis consisting of cermet 17Ni/83(10NiO-90NiFe2O4) was prepared and the operating performance was evaluated in a laboratory cell with the electrolyte CR2.3 and Al2O3 concentration 7.43% (mass fraction). The results indicate that no major operational difficulties are encountered during the testing which lasts for 101.5 h and the inert anode exhibits good general performances. The steady-state average concentration of impurity Ni in the bath is close to the solubility, however, the Fe concentration is lower than its solubility. The contents of the main contaminants for aluminum produced are Ni 0.128 8%, Fe 1.007 4%. The corrosion rate of inert anode under electrolysis conditions based on the content of impurity Ni in metal aluminum is approximately 8.51 mm/a.
Ni/(10NiO-90NiFe2O4)cermet inert anodes with metal Ni content of 0,5,10,15 and 20(mass fraction,%)were prepared and their corrosion behavior in Na3AlF6-Al2O3 melts was investigated in laboratory electrolysis tests.The results indicate that the content of metal Ni in anodes has little effect on the steady-state concentration of impurities Ni and Fe in electrolyte and the values range in(114-173)×10- 6and(287-385)×10 -6,but the content of impurities in the metal aluminum manifolds.There is preferential corrosion for metal Ni in NiO-NiFe2O4 based cermet anodes.Considering the corrosion resistance and electrical conductivity,the cermet containing 5%Ni(mass fraction)behaves best among NiO-NiFe2O4 based cermet anodes studied,and should be further studied.
