Characteristics of Anodic Dissolution for Al-Cu Alloys in EmImCl-AlCl3 Ionic Liquid

Abstract

To produce high-purity Al from Al–Cu alloys, the dissolution behaviors of various Al–Cu binary alloy anodes in EmImCl–AlCl3 ionic liquid have been investigated at 323 K. In the constant potential electrolysis of the Al–5.0Cu casting alloy and cold-rolled plate at 0.3 V, Al atoms in the matrix phase were preferentially dissolved followed by the formation of Al2Cu surface species. The dissolution of both Al2Cu and Al in the alloy matrix occurred during electrolysis at 0.8 and 1.2 V. Moreover, a Cu-rich layer derived from Al2Cu was formed on the cold-rolled plate surface at a potential of 0.8 V and high electric charge densities. From the results, potential dependence of the anodic dissolution of the Al−Cu alloys in the ionic liquid was clarified.