Aluminium electrowinning cells with sloping foraminate oxygen-evolving anodes

Abstract

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