Rotary kiln calcined bauxite is obtained by calcining superior grade bauxite at high temperatures (from 850 to 1600) in the rotary kiln. 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%. Besides, through calcination, the density and refractory resistance will also be improved to varying degrees. The grade of bauxite can be increased greatly.
