IMPROVED ALUMINUM REDUCTION TECHNOLOGY TO EXPLOIT NON-CONSUMABLE ANODES

A NEW CONCEPT OF A SLURRY ELECTROLYTE CELL FOR PRIMARY ALUMINUM EMPLOYING A NON-CONSUMABLE ANODE IS PRESENTED. THE FINE-PARTICLE ALUMINA SLURRY CONCEPT ALLOWS CELL OPERATION AT A TEMPERATURE OF 700 DEGREES CENTIGRADE AS COMPARED TO 950 DEGREES-980 DEGREES CENTIGRADE IN CONVENTIONAL HALL-HERAULT CELLS. THE LOWER OPERATING TEMPERATURE IS EXPECTED TO MAKE PRACTICAL THE STATE-OF-THE-ART CERMET ANODES DEVELOPED ELSEWHERE. DIMENSIONALLY-STABLE TITANIUM DIBORIDE CATHODES ARE ALSO EXPECTED TO BECOME PRACTICAL. NEW, LESS-CAPITAL INTENSIVE CELL DESIGNS THEN BECOME PRACTICAL. REVIEW OF THE LITERATURE SHOWS THAT THERE ARE ELECTROLYTE COMPOSITIONS THAT HAVE THE APPROPRIATE PROPERTIES. DESIGN CALCULATIONS ON LIMITING CURRENT DENSITIES, ELECTROLYTE CIRCULATION RATE BY OXYGEN GAS LIFT, PARTICLE SETTLING RATES, AND OTHER FACTORS INDICATE EMINENT FEASIBILITY. INVESTIGATION WITH SMALL SCALE LABORATORY CELLS IS PROPOSED FOR PHASE I.