ABSTRACT
Aluminum is the third most abundant element in the earth’s crust, and so plenty of aluminum-bearing minerals are available in nature. The bauxites that involve a less complicated process to get aluminum-containing phases are called as recoverable bauxites and those sources and reserves are economically important. Naturally occurring mineral, mainly bauxite, is purified by chemical treatment to remove the impurities and then calcined produces synthetic alumina. It was initially produced from bauxite in 1888 using the Bayer process. Fused alumina is also used for making alumina refractories mainly to improve the corrosion resistance. It is produced by the electrofusion route. In fused alumina, alumina crystals grow from a molten stage, and the growth rate is very high compared to solid state growth resulting in very large crystals when solidified as fused alumina. Alumina refractories cover a wide class of refractories having a wide variety of alumina content and other secondary oxides.
