Potentiostatic studies of processes on liquid aluminium cathode during electrolysis of lanthanum-bearing melt with soluble anode

A potentiostat has been used to study the processes occurring in the liquid aluminium cathode during the electrolysis of the melt KCl-NaCl-3.1 mass % La3+. A potential region -(2.40 to 2.57) V has been established corresponding to the highly efficient deposition of lanthanum both in the potentiostatic and galvanostatic conditions. It is shown that potentiostatic electrolysis at phi3=-2.55 V may result in the production of aluminium alloys with 17 mass % La and cathode current output eta=100%. Galvanostatic electrolysis realized at isub(k)=(0.3-0.4) A/cm2 up to phisub(k)sup(max)=-2.55 V gives Csub(La(Al))=12 mass % with eta approximately 85%