What is Hall–Héroult process?

The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide in molten cryolite, and electrolyzing the molten salt bath, typically in a purpose-built cell. The Hall–Héroult process applied at industrial scale happens at 940–980 °C and produces 99.5–99.8% pure aluminium. Recycled aluminum requires no electrolysis, thus it does not end up in this process. This process contributes to climate change through the emission of carbon dioxide and fluorocarbons in the electrolytic reaction and consumption of large amounts of electrical energy.