Rotary Kiln Calcined Bauxite used for refractory.

Bauxite is usually  because it is almost always found near the surface of the terrain, with little or no . Approximately 70% to 80% of the world's dry bauxite production is processed first into , and then into aluminium by  as of 2010. Bauxite rocks are typically classified according to their intended commercial application: metallurgical, abrasive, cement, chemical, and refractory.

Usually, bauxite ore is heated in a pressure vessel along with a  solution at a temperature of 150 to 200 °C. At these temperatures, the  is dissolved as an aluminate (the). After separation of ferruginous residue () by filtering, pure gibbsite is precipitated when the liquid is cooled, and then seeded with fine-grained aluminium hydroxide. The gibbsite is usually converted into , Al₂O₃, by heating. This mineral is dissolved at a temperature of about 960 °C in molten . Next, this molten substance can yield metallic aluminium by passing an  through it in the process of electrolysis, which is called the , named after its American and French discoverers.

Prior to the invention of this process in 1886, elemental aluminium was made by heating ore along with elemental  or  in a . The method was complicated and consumed materials that were themselves expensive at that time. This made early elemental aluminium more expensive than .