Patent ID: 8025785

Claim:
A cell for the electrowinning of aluminium from alumina dissolved in a molten electrolyte, comprising a generally horizontal cell bottom on which a pool of product aluminium is collected and at least one electrically conductive cathodic element having one or more sloping upper aluminium-wettable drained active cathode surfaces separated by an anode-cathode gap from one or more anodes with corresponding sloping active anode surfaces, wherein the cathodic element comprises an inclined cathodic wall in the electrolyte above the generally horizontal cell bottom, the cathodic wall having: a) an upwardly-oriented inclined face that forms the sloping upper aluminium-wettable drained active cathode surface(s) on which aluminium is produced and drains into the aluminium pool; b) a downwardly-oriented inclined face which is in contact with the molten electrolyte and which overlies the aluminium pool; c) a bottom end on the cell bottom in the aluminium pool; and d) a passage in a bottom part thereof for the aluminium pool and/or for a flow of alumina-rich electrolyte from behind the active cathode surface(s) to a bottom part of the anode-cathode gap, the aluminium pool covering substantially the entire cell bottom including underneath the cathodic wall.