Electrochemical Reduction of Zirconia in Melts Based on Mixture of Calcium Chloride and Calcium Oxide

It has been found that the reduction of zirconium dioxide from the CaCl2-NaCl-CaO and CaCl2-LiCl-CaO melts involves calcium and gallium intermetallics, which are formed during the cathodic polarization of the gallium cathode, calcium being not consumed for reduction, and evolved oxygen being discharged at the anode. Zirconium deposits on the gallium cathode as a fine powder, whose specific surface area decreases with increasing current density. Calcium is discharged at the gallium cathode irreversibly with considerable depolarization. The degree of zirconium reduction is the higher, the lower the acid strength of the oxide-chloride melt.