Abstract
A theoretical analysis of the relevant thermodynamic and electrochemical data revealed that the electrolytic regeneration of the calcium reductant and the solvent salt from the spent salt of the neodymium oxide reduction process is feasible. Electrolytic decomposition of 
dissolved in 
molten salt between a graphite anode and a Ca‐Zn molten pool cathode was achieved at a potential higher than 2.2V, which was determined from current‐voltage curves. Calcium recovery in the range of 10 to 20% was obtained in these experiments. Electrolytic calcium transport experiments proved that the poor calcium recovery was not due to difficulty of calcium incorporation into the Ca‐Zn molten pool cathode. Chemical equilibrium experiments along with chemical analysis of the phases established that the parasitic formation of calcium carbonate at the anode was the primary reason for the low calcium recovery.