How much alumina can be produced from four tons of bauxite?

Refining four tons of bauxite typically yields about two tons of alumina.1

The production of alumina from bauxite is primarily achieved through the Bayer process, which involves digestion, clarification, precipitation, and calcination to remove impurities such as iron oxide, silica, and titania. This refining step is essential, as these impurities must be eliminated before the alumina can be processed into metallic aluminum via the Hall-Héroult electrolytic process.21