Aluminium electrowinning cells with sloping foraminate oxygen-evolving anodes

摘要

A cell for the electrowinning of aluminum (50) from alumina, comprises an inclined plate-like or grid-like open anode structure (25) which has a generally v-shaped configuration in cross-section. The anode structure (25) has a downwardly-oriented sloping electrochemically active surface that is generally v-shaped in cross-section and spaced above an upwardly-oriented corresponding sloping cathode surface (11) by an anode-cathode gap (40) in which alumina dissolved in a circulating electrolyte (60) is electrolysed. The anode structure (25) has a plurality of anode through-passages (45) distributed thereover for an up-flow of alumina-depleted electrolyte (60) from the anode-cathode gap (40). One or more electrolyte guide members (30,30′,30″) located above the open anode structure (25) is/are arranged to guide substantially all the up-flowing alumina-depleted electrolyte (60) to an alumina feeding area (63), where it is enriched with alumina and then over and around an upper end (27) of the generally v-shaped plate-like or grid-like anode structure (25) into the anode-cathode gap (40). Alumina-enriched electrolyte (60) can be fed into a lower end and/or into an upper end of the anode-cathode gap (40).