Electrolysis of High-Purity Aluminum in a Novel Series Cell

A novel series cell containing an inert anode, a bipolar electrode and a graphite cathode was applied for producing high-purity alu-minum by electrolysis in cryolite-alumina melts. The bipolar electrode is an Al-Cu liquid alloy held by a porous graphite plate. During electrolysis, evolution of oxygen mainly took place on the surface of inert anode; both aluminum and impurities reduced simultaneously at the cathodic surface of bipolar electrode; while only electrochemical dissolution of aluminum occurred at the an-odic surface of bipolar electrode; consequently, high-purity aluminum reduced at the surface of graphite cathode