The Electrolytic Process for Aluminium Production

The industrial production of aluminium is based, since the end of the nineteenth century, on the electrolysis process. Aluminium is in fact not present in the nature in its pure metallic form but as an oxide called Alumina (Al 2 O 3) and an adapted processing (electrolysis) is to be used to extract the metal. Aluminium electrolysis is performed in large Hall-Heroult cells, as illustrated for an industrial setting in Fig. 12.1. In the aluminium industry, these cells are connected electrically in series and supplied with direct current (DC). The electric current is supplied to the cells through metal busbars made of aluminium or copper. Figure 12.2 gives a schematic representation of one Hall-Heroult cell.