MASS-TRANSPORT CONSIDERATIONS FOR THE DEVELOPMENT OF OXYGEN-EVOLVING ANODES IN ALUMINUM ELECTROLYSIS

Oxygen-evolving, non-consumable anodes are being developed for use in industrial aluminum production. Ceramic-type electrodes dissolve slowl y into the electrolyte, a process governed by mass transport condition s. For achievable anode life, factors determining mass transfer rates at the cathode are generally more important than those at the anode. T his is discussed by means of model calculations and using experimental results. The roles of incomplete alloying of anode constituents with the aluminum upon reduction at the cathode and of metal dissolution fr om the cathode are also treated. (C) 1997 Elsevier Science Ltd.