Patent ID: 6425992
Filing Date: 2002-07-30
Classification: C25C

Abstract:
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, having a metal-based oxidation resistant substrate to which an adherent electrochemically active multi-layer coating is applied prior to its immersion into the electrolyte and start up of the electrolysis by connection to the positive current supply, the electrochemically active multi-layer coating being obtainable from a plurality of applied layers selected from:a) a liquid solution, b) a dispersion in a liquid or a paste, c) a suspension in a liquid or a paste, or d) a pasty or non-pasty slurry, and combinations thereof, with or without heat treatment between two consecutively applied layers the multi-layer coating after final heat treatment being electrically conductive and having during operation in the cell an electrochemically active surface for the oxidation of oxygen ions present at the surface of the anode, at least one layer applied from said selection of layers being obtainable from a polymeric and/or colloidal carrier, wherein said at least one layer is obtainable fromsaid polymeric carrier contained in a liquid solution, a dispersion, a suspension or a slurry; or said colloidal carrier, or said polymeric and colloidal carriers, contained in a dispersion, a suspension or a slurry.