Preparation of High-purity Alumina by Hydrolyzing High-Purity Metal Aluminum

This paper puts forward a new method for the preparation of 99.999% high-purity alumina used for the LED underlay sapphire, which has above 99.999% high-purity aluminum atomized the active aluminum powder by the supersonic multistage cooling way, then makes the powder form the hydrate of the alumina through the hydrolyzing reaction, and finally gets 99.999% high-purity alumina by means of the calcinations and the follow-up granularity treatment. By the processing way, the reactant is only aluminum and water, and there is no other additive, which profitably keeps the product pure and completely satisfies the requirements of synthetic crystals while tested.