Preparation process of rotary calcined bauxite

The main component of bauxite is aluminum oxide (Al2O3), which is an mineral containing impurities of hydrated aluminum oxide. It is white or off-white, brownish yellow or light red due to iron content. The density of bauxite is 3.9~4g/cm3, hardness 1~3, opaque, brittle and extremely difficult to melt. It is insoluble in water, but can be dissolved in sulfuric acid and sodium hydroxide solution. It is mainly used in aluminum refining and refractory material preparation.

The bauxite calcination process is a complex process of making raw bauxite into bauxite clinker after calcination at high temperature (1200~1700℃). The material enters the kiln from the up side of the rotary kiln and is calcined. Due to the inclination and slow rotation of the barrel, the material both rolls in the circumferential direction and moves axially (from the up side to the down side). The produced clinker enters the cooler. As the calcination temperature increases and the holding time increases, the aluminum content increases and so does the grade of the bauxite.

The traditional bauxite calcination process: raw materials → storage → crushing → grinding → pressing and filtering → mud training → extrusion → drying → calcination → crushing → products. Due to the unstable composition of bauxite raw material, the quality of bauxite clinker obtained by this traditional calcined bauxite clinker production process is not high and the product quality is not stable. In order to get good quality bauxite clinker, a new bauxite homogenizing material calcination process has been invented: raw material → storage → crushing → grinding → desiliconization → wet homogenization → overpressing and filtering → mud training → extrusion → drying → calcination → crushing →product.