Bauxite ore is one of the primary source of aluminum but it must first be chemically processed to produce alumina (aluminum oxide). The next step of aluminum production is smelting of alumina using an electrolysis process (Hall-Heroult process). This electrolysis process is driven by electrical current. Electrolyte (molten salt) with immersed carbon anodes is used in order to dissolve the alumina. Carbon anodes are carrying electrical current and thee chemical bond between aluminum and oxygen in the alumina is broken.