ALUMINA

Alumina, also called alumina, is a synthesized alumina, Al 2 O 3, a white or almost colorless crystalline substance that is used as a starting material for melting metallic aluminum. It also serves as a raw material for a wide range of modern ceramics and an active ingredient in chemical processing. Alumina is made from bauxite, a natural ore containing different amounts of aqueous (water-containing) alumina. Free Al 2 O 3 occurs naturally as a mineral. corundum and its forms of precious stones, sapphire and ruby; they can be synthesized from alumina and are actually sometimes called alumina, but this term is more precisely limited to the material used in aluminum metallurgy, industrial ceramics and chemical processing.