Patent ID: 6572757
Filing Date: 2003-06-03
Classification: C25C

Abstract:
An electrolytic cell for electrowinning of aluminium from alumina dissolved in a fluoride-containing molten electrolyte, the cell comprising a plurality of anodes immersed in a molten electrolyte, each anode having an oxygen-evolving active surface of open structure facing and spaced by an inter-electrode gap from a cathode; a thermal insulating cover above the molten electrolyte surface; and an alumina feed device arranged above the molten electrolyte surface for supplying alumina to the molten electrolyte surface from where the alumina is dissolved as it enters the electrolyte to enrich the electrolyte in dissolved alumina, alumina-containing electrolyte being electrolysed in the inter-electrode gaps to produce oxygen gas on the anodes and aluminium on the cathode, wherein the alumina feed device comprises means for spraying and/or blowing alumina sidewards between the molten electrolyte surface and the thermal insulating cover and over an entire expanse of the surface of the molten electrolyte, so that upon dissolution of alumina sprayed and/or blown to the electrolyte, electrolyte enriched in dissolved alumina flows down to the inter-electrode gaps.