Calcined alumina powder is produced by calcining industrial aluminum hydroxide or industrial alumina at an appropriate temperature to obtain a crystalline stable α-alumina product; it is made into alumina micro powder through ball milling using calcined α-alumina as raw material. Calcined alumina powder is generally used in shaped refractory products such as skateboards, the three major components, and corundum bricks, or in combination with activated alumina for use in unshaped refractory materials.
When using calcined alumina powder to produce resin-bonded products, its low moisture content allows for easy and uniform mixing, and it has high volume stability. When combined with active alumina micro powder or silica fume for use in amorphous refractory materials, it can form a particle gradation with finer micro powders to achieve the closest packing, reduce water addition and porosity, decrease linear change rate, and increase strength.