Electrowinning of Light Metals from Molten Salts Electrolytes

Light metals such as lithium, sodium, potassium, magnesium and aluminium may be produced by molten salts electrolysis. Aluminium is produced by the Hall-Heroult process by electrolysis in molten salts. It is by far the largest in terms of production volumes and for metals second only to iron and steel, but it carries a very high carbon footprint mainly due to the wide-spead use of electricity based on based on coal. Magnesium is currently produced by silicothermic reduction of MgO according to the Pidgeon process. However, electrolysis in molten chloride electrolytes using MgCl 2 as feedstock may return as it is more sustainable. The current Kroll process for producing titanium is energy intensive and requires lots of work as well as having very low productivity. Sodium is produced by electrolysis in a chloride electrolyte. This process may be improved by using sodium oxide as raw material and inert oxygen evolving anode.