Boemite
Boemite is an
aluminium oxide hydroxide
(γ-AlO(OH)) mineral, a component of the aluminium ore
bauxite
and plays a role in the production of aluminium. Bauxit has been first found in Les Baux, France (hence its name) and is, for example, reduced to aluminium through the
cryolite process, a fused-salt electrolysis. Aluminium, the third most common element of the earth lithosphere, in turn is used for many components. It is mainly valued for its lower weight and corrosion susceptibility compared to iron. It is used in modern vehicle and aircraft construction for example.
As aluminium also has a good electrical conductivity e.g. the wires in the Airbus A 380 are produced of aluminium to reduce weight. But also the aluminium oxides themselves are used in production and technology. Because of their thermal resistance boemite and other aluminium oxides are used as catalyst support in the oil and chemical industries. In the paint and plastics industries they serve as thickeners and fillers or to reduce stickiness and increase scratch resistance. They can also have a positive effect on the colour brilliance of lacquers.
Other areas of application are
- ceramics (to achieve high refractoriness and abrasion resistance),
-
additives for paper production (so the paper won’t stick to the transport rollers during the high speed processes),
-
synthetic gemstones like sapphires or yttrium-aluminium garnet (the latter is used in high energy lasers for example)
-
phosphors using aluminium oxides as carrier materials.
Corundum, a close relative of boemite, is used as an abrasive agent for polishing workpieces whereas zeolites, alkali or alkaline earth alumosilicates, are used in chemical engineering
but also as cat litter in cat's litter trays.
Literature
