Alumina is a colloidal mixture composed of three aluminum hydroxides in different ratios. According to its use, it is divided into metallurgical grade, chemical grade, refractory grade, grinding grade, cement grade, etc. Used to make refractory materials, this kind of bauxite is called refractory bauxite. Bauxite clinker with proper ratio of AL2O3/Fe2O3 and AL2O3/SiO2 is used to melt alumina. Bauxite clinker with proper ratio of AL2O3 and AL2O3/SiO2 is used to melt alumina.
Bauxite has strong resistance to acid and alkaline slag erosion, and has high high temperature strength. It is widely used in steel, non-ferrous metals and other industries, but its resistance to rapid cold and heat is poor, and its volume stability at high temperature is not good, resulting in material deformation and peeling Reduce the service life of the material. At present, the method of adding synthetic mullite is basically adopted in China to overcome its shortcomings. However, the high price of synthetic mullite limits its use. Bauxite has a wide range of uses in the refractory and aluminum industries. The most basic use of bauxite is in the metallurgical sector producing aluminum, accounting for 85% of the total bauxite consumption. The remaining bauxite consumption can be divided into two categories: special alumina and "other". Special aluminum bauxite is used to produce nitroplate aluminum, calcined alumina and activated alumina, accounting for 10% of the total bauxite consumption tray. The "other" category refers to bauxite that is directly used for mining in the refractory, cement and corrosive industries. In terms of market size and value, refractory bauxite occupies an important position in this non-metallurgical market end use.