730 u00b0 c in the phase diagram of lif prf 3 by adopting an electrolytic bath temperature higher than the melting point of the electrolytic bath the deposited pr fe is liquefied on the cathode after the deposition and since the liquid is heavier than the fused salt the alloy is deposited in the fused salt below the electrode furthermore the composition of pr fe can be controlled by controlling the electrolysis temperature accordingly the electrolysis is possible if the electrolytic bath temperature is higher than the melting point of the electrolytic bath namely the electrolytic bath temperature is not lower than 760 u00b0 c which is slightly higher than 730 u00b0 c and is preferably in the range of 760 u00b0 to 1100 u00b0 c however if the electrolytic bath temperature is elevated oxidative consumption of the electrode is increased and damage of the cell material is promoted furthermore from the relations of the electrolytic bath temperature to the critical anode current density current efficiency and bath composition if the bath temperature is either too high or too low the current efficiency is reduced and the critical anode density is greatly changed accordingly from the economical viewpoint it is preferred that the electrolytic bath temperature be in the range of about 850 u00b0 to about 1050 u00b0 c determined after general consideration of the above relations the temperature of the electrolytic bath can be controlled only by heat generated by an electric current between the electrodes and in fact in the conventional fused salt electrolysis process this internal heating method is often adopted however in the process of the present.