DRAINED-CATHODE ALUMINIUM ELECTROWINNING CELL WITH IMPROVED ELECTROLYTE CIRCULATION

摘要

A drained-cathode cell for the electrowinning of aluminium comprises one or more anodes (14) suspended over one or more cathodes (16). The or each anode (14) and cathode (16) respectively have a sloped V-shaped active anode surface (22) and parallel sloped inverted V-shaped drained cathode surfaces (18) facing one another and spaced apart by two sloped inter-electrode gaps (20), arranged so the electrolyte circulates upwardly in the sloped inter-electrode gaps (20) assisted by anodically produced gas and then returns from a top part (22') to a bottom part (22'') of each inter-electrode gap (20) along an electrolyte path (26, 27, 36, 37). Each electrolyte path (26, 27, 36, 37) extends through vertical and horizontal passages as follow: a vertical passage (27) from a top to a lower part of a cathode (16) and then a horizontal passage (26) in or under the lower part of the cathode (26), and/or a horizontal passage (36) in or on an upper part of an anode (14) and then a vertical passage (37) extending from the upper to a bottom part of the anode (14). Each horizontal passage (26, 36) extends substantially over the entire horizontal length of a corresponding inter-electrode gap (20).