Refractory Grade Calcined Bauxite

With a variety of uses of calcined bauxite, Rain Gold Group offers refractory grade material that offers high refractoriness, moderate slag resistance, good mechanical strength and many other benefits. Used in a variety of industries, the company makes sure the clients get the best out of it.

"Bauxite, an aluminium ore, is the world's main source of aluminium. It consists mostly of the minerals gibbsite Al(OH)3, boehmite γ-AlO(OH) and diaspore α-AlO(OH), mixed with the two iron oxides goethite and haematite, the clay mineral kaolinite and small amounts of anatase TiO2. Calcined Bauxite is used as raw material for manufacturing fused alumina and high alumina refractories. On an average 4-5 tonnes of bauxite are needed to produce two tonnes of alumina from which only one tonne of aluminium can be produced. Aluminium is possibly the most versatile product with applications in almost every industry and since bauxite is the primary source for aluminium it will always be in great demand. 15% of bauxite goes into refractory, chemical , cement ,abrasives and other applications.
Bauxite is usually strip mined because it is almost always found near the surface of the terrain, with little or no overburden. Approximately 70% to 80% of the world's dry bauxite production is processed first into alumina, and then into aluminium by electrolysis as of 2010. Bauxite rocks are typically classified according to their intended commercial application: metallurgical, abrasive, cement, chemical, and refractory.
Usually, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as an aluminate (the Bayer process). After separation of ferruginous residue (red mud) by filtering, pure gibbsite is precipitated when the liquid is cooled, and then seeded with fine-grained aluminium hydroxide. The gibbsite is usually converted into aluminium oxide, Al2O3, by heating. This mineral is dissolved at a temperature of about 960 °C in molten cryolite. Next, this molten substance can yield metallic aluminium by passing an electric current through it in the process of electrolysis, which is called the Hall–Héroult process.
Calcined Bauxite is obtained by calcining (heating) superior grade Bauxite at high temperature (from 850 °C to 1600 °C). 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 % to 88 %. The heating is carried out in rotary kilns. We produce Calcined Bauxite for various applications such as refractory bricks, abrasives, steel polishing, etc. We are committed to provide consistency in quality and availability of product at extremely competitive prices. "