Bauxit

A general term for a rock composed of hydrated aluminum oxides. It is the main ore of alumina to make aluminum. Also used in the production of synthetic corundum and aluminous refractories.The bauxite is purified by the Bayer Process. First the ore is mixed with a hot concentrated solution of sodium hydroxide. The NaOH will dissolve the oxides of aluminum and silicon but not other impurities such as iron oxides, which remains insoluble. The insoluble materials are removed by filtration.1:description: calcined bauxite is one of the principal ore of aluminum. Calcined bauxite contains hydrous aluminum oxides and aluminum hydroxides, formed through the laterization of aluminous rocks in tropical and subtropical areas .calcined bauxite is obtained by calcining (heating)superior grade bauxite at high temperature (from 85OC to 1600C) .this removes moisture thereby increasing the alumina content. compared to an alumina content of about 57%to 58%in raw bauxite, calcined bauxite has an alumina content of 84%to88%.the heating is carried out in rotary kilns. 2:applicationg: calcined bauxite is typically calssified according to its intended commercial application,such as abrasive ,cement ,chemical l, metallurgical, and refractory .as raw material for use in high alumina and super duty refratory bricks and shapes ,plastics ,castable refratory, motors, gun mixes, ramming mixes, abrasive grains and other products chemical composition refractoriness