Bauxit ist das wichtigste Aluminiumerz.
Es entstand im Laufe von Millionen Jahren und ist das Restprodukt chemischer Verwitterung aus Felsen, die Aluminiumsilikate enthielten. Zuerst wurde Bauxit 1821 in Frankreich und anschließend an zahlreichen Fundorten auf der ganzen Welt entdeckt. Hydro ist an zwei Bauxitminen in Brasilien beteiligt.
- Bauxite occurrences are widespread, mostly in tropical areas where there has been intense weathering to generate bauxite, however resources are tightly held by a few competitors
- Bauxite usually occurs in a thin layer (typically 2 to 5 meters) near or at the surface
- Worldwide production is about 250 million tonnes, and has been growing at an annual rate above 5% for the past decade, driven largely by Chinese demand growth
- Bauxite is a mixture of minerals that contain various concentrations of hydrated aluminum oxides, as well as impurities. The primary ore minerals are gibbsite (alumina tri-hydrate), boehmite and diaspore (alumina monohydrates)
- Gibbsite-rich bauxite is preferred as it can be refined at lower digestion temperatures than the other types of alumina bearing minerals
- Bauxite is usually reddish-brown, but can also be white, tan, and yellow, depending on the type and concentration of iron minerals present. It also has a wide range of textures, but is typically dull to earthy in luster and can look like clay or soil
- Alumina for metallurgical purposes
- Chemical applications