Alumina clinker is raw bauxite, which is calcined at high temperatures in the rotary converter. Water of crystallization is removed through calcination to increase alumina content. The clinker is gray white, light yellow, and dark gray. It has high fire resistance, low expansion coefficient, high hardness, stable performance, environmentally friendly use, and no harmful gas discharge, and it can replace other non-environmentally friendly materials. Widely used in refractory materials, aluminum smelting industry, precision casting, grinding materials, refractory pouring materials, ceramic chemicals, and other fields.