The ultra high-purity alumina powder we are supplying whose purity can be 99.998%+. The powders are produced by direct hydrolysis. There are two crystal phases: alpha and gamma. And the particle size can be controlled between 50nm and 30um, which can be customized according to customer requirements. This series of products have stable quality and can be used in the production of artificial sapphire, wear-resistant and heat-conducting filler, polishing materials, super ceramics (bioceramics, electronic ceramics, etc.), wear-resistant coatings, catalyst carrier and many other fields.