Abstract: A process for the electrowinning of aluminium from alumina dissolved in a fluoride-based molten electrolyte in a cell operating at reduced temperature, typically below 870° C., utilising nickel-alloy based anodes, in particular nickel-iron alloy anodes. The electrolyte contains AlF3 in such a high concentration, usually above 20 weight %, in addition to cryolite, that fluorine-containing ions rather than oxygen ions are oxidised on the anodes. However, only oxygen is evolved, the evolved oxygen being derived from the dissolved alumina present near the anodes. The anodes may be porous at the surface so as to provide a high active surface area for operation at low current density.

Abstract: A method for producing a metal in an electrolysis cell comprising an anode, a carbon cathode, and a chamber containing a metal oxide dissolved in a molten salt bath, said method comprising: coating an outer surface portion of the cathode with a coating composition consisting of a refractory metal, a paint comprising an organic polymeric binder, and aluminum powder, and optionally an organic solvent and an oil; and optionally a boron source; curing the coating composition by heating it to an elevated temperature, producing an aluminum-wettable coating on the cathode outer surface portion; and electrolyzing the metal oxide to a metal bypassing an electric current in the molten salt bath between the anode and the coated cathode.