Electrodeposition of lanthanum metal from fused chloride bath

Preparation of lanthanum metal from fused chloride bath is described. Anhydrous lanthanum chloride dissolved in sodium chloride - potassium chloride eutectic was electrolysed above the melting point of metal to get it in fused st ate. Lanthanum metal upto 1.5 kg has been prepared per batch. The specially designed cell has the provision of continuous feeding during elctrolysis and provision to drain out molten electrolyte after electrolysis, thus facilitating metal-slag separation. The effect of parameters such as cathode current density, temperature of electrolysis and bath composition on current efficiency were studied. Current efficiency upto 95% and metal yield upto 88% were achieved. By careful control of feed material and cell atmosphere, metal over 99% purity coul d be obtained. The metal was analysed for gaseous and other impurities and evaluated for its tensile strength and hardness. (author). 10 refs., 4 tabs