CORROSION OF ZINC FERRITE IN NaF-AlF_3-Al_2O_3 MOLTEN SALTS

Zinc ferrite was used as inert anode materials for aluminum electrolysis.The corrosion behavior of zinc ferrite as investigated under the anodic current density of 0-2.5A/cm2. Experimental results prove that zinc ferrite materials is very corrosion resistant to molten NaF-AlF3-Al2O3 under anodic polarization.The biggest corrosion rate appears in the range of 0.5~0.75A/cm2.The corrosion rate will get down after that peak value. High anodic current density (1.5 A/cm2), high alumina concentration and low mole ratio of NaF/AlF3 in the molten salts would be the most important conditions for using inert anode.