Corrosion Behavior of ZrO2(f)-NiFe2O4 Inert Anode in Cryolite Molten Salt
ZrO2（f）-NiFe2O4惰性阳极在冰晶石熔盐中的腐蚀行为

NiFe2O4 spinel was synthesized via solid-state sintering technology using NiO and Fe2O3 as raw materials,and ZrO2(f)-NiFe2O4 inert anode was prepared by adding ZrO2 fibers ZrO2(f)] into NiFe2O4.The static thermal corrosion rate and electrolytic corrosion rate of inert anode samples in cryolite molten salt were measured by weight-loss method,and their corrosion mechanism was examined by SEM,EDX and XRD analysis.The experimental results indicate that the porosity of anode samples is increased from 4.9% to 5.8% with the increase of ZrO2(f) from 0 to 4%(ω),which leads to the increase of static thermal corrosion rate from 3.8 to 4.3 mg/(cm2·h).The dissolution reactions of oxides in cryolite molten salt are inhibited in the electric field.The electrolytic corrosion rate of anodes samples containing 3%(ω) ZrO2(f) is 2.2 mg/(cm2·h),which is much lower than its static thermal corrosion rate,and both corrosions are controlled by physicochemical dissolution.ZrO2(f) has excellent stability in cryolite molten salt at high temperature,and can be used for the reinforcement of NiFe2O4 based inert anodes in aluminum electrolysis.