Alumina

Alumina is refined aluminum oxide, produced from bauxite, that is smelted using large amounts of electricity to make metallic aluminum.

Alumina, aluminum oxide, is what bauxite becomes after a chemical refining process strips away impurities, leaving a white powder that is the direct input to aluminum smelting. It sits in the middle of the aluminum supply chain, too refined to be called ore but not yet metal.

Smelting alumina into aluminum requires large amounts of electricity, so alumina refineries and aluminum smelters are often built in different places: refineries near the bauxite mines that feed them, smelters wherever power is cheapest, sometimes on a different continent entirely. This split means alumina itself is a significant traded commodity, shipped from refineries to smelters that may have no bauxite or alumina production of their own nearby.