Patent ID: 6656520
Filing Date: 2003-12-02
Classification: C25C

Abstract:
A method of manufacturing a non-carbon, metal-based, high temperature resistant, electrically conductive and electrochemically active anode of a cell for the production of aluminium by the electrolysis of alumina dissolved in a fluoride-containing electrolyte, comprising forming onto a metal-based substrate one or more layers applied from:a) a liquid solution, b) a dispersion in a liquid or a paste, c) a suspension in a liquid or a paste, and d) a pasty or non-pasty slurry, and combinations thereof with or without one or more further applied layers, with or without heat treatment between two consecutively applied layers when at least two layers are applied; and exposing the coating to a final heat treatment so as to render it electrically conductive and electrochemically active during operation in the cell for the oxidation of oxygen ions present at the surface of the anode to form monoatomic nascent oxygen which as such or as biatomic molecular gaseous oxygen oxidises or further oxidises the surface of the coating, or part or most of the coating or the surface of the substrate, to form a barrier to the ionic and gaseous oxygen at least a limited barrier to the nascent monoatomic oxygen, said coating having a slow dissolution rate in the fluoride-containing electrolyte.