Alpha-alumina is divided into the following categories

1. Common α-Al2O3

The preparation of α-Al2O3 with different morphologies is essentially to introduce physical or chemical methods to finalize the final formed structure while adjusting the control factors of crystal transformation, so as to achieve synergistic or inhibiting effects.
2. High purity and fine powder α-alumina

High purity α-Al2O3 is also a widely used material, which is often used in integrated circuits and other fields, as a LED sapphire substrate to use, precision ceramic parts in the semiconductor field also often have purity requirements for products, need to use high purity aluminum oxide powder to prepare.

3. Nano-α-alumina -- nanospheres, nanosheets/strips and nanowires, etc. 

Because of its special structure and physical and chemical properties, α-Al2O3 is often used in industrial fillers, catalysis and other applications. The poor surface activity of α-Al2O3 can usually be improved by increasing the specific surface area, and preparing it into nanoscale materials is a better improvement strategy.

4. Catalytic carrier α-alumina

α-Al2O3, as a catalytic carrier, mostly exists in the above form with higher purity, but the surface usually needs to be treated in various ways to have a better active center loading capacity. Hydrated aluminum oxide powder was combined with pore-making agent, binder and other additives, and then calcined at high temperature to obtain ethylene oxidation catalyst carrier with large specific surface area, anti-sintering and good thermal conductivity. The α-Al2O3 prepared by this method has low cost, low wear, high purity and high strength.