Recent developments in the field of low-temperature electrolytes and electrolysis are considered. Although the investigations have not found fundamental problems in low-temperature aluminum electrolysis development as an industrial process, challenges remain in cell design, construction, and operation of cells with these emerging technologies.

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Salt mixtures based on sodium or/and potassium fluorides were tested as electrolyte for oxygen evolving anodes. Electrolyte compositions used in experiments were suggested on the basis of suitable alumina solubility and dissolution rate in the previous papers. Platinum, cermets and Ni-Cu-Fe based metal alloys were tested as inert anodes. Preferable inert anode materials with low polarization, suitable high current density range and low corrosion rate for low-temperature electrolyte systems were proposed.

The rate of oxygen evolution on metallic inert anodes was measured as a function of current density during electrolysis of a low-melting NaF(12)-KF-AlF 3 bath ([NaF ? KF]/[AlF 3 ] = 1.5 mol mol -1 ) at 800°C. The oxidation rate of the anode substrate (A cm -2 ) was calculated. The anode oxidation process was depressed at the potentials of oxygen evolution. The dynamics of the decrease in the oxidation rate, which were obtained in previous study by the change in geometrical size of the metallic part of the specimen, was reproduced both by the technique proposed and also in potentiostatic electrolysis at potentials below that of oxygen evolution, in some cases, depending on prepolarisation.

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