METHOD FOR PRODUCING alpha-ALUMINA PARTICLE

摘要

PROBLEM TO BE SOLVED: To provide a method for producing anα-alumina particle suitable for a polishing material and having a size of >5μm average primary particle diameter and a narrow distribution of particle size and a polyhedral form of a uniform shape. SOLUTION: This method for producing theα-alumina particle comprises baking aluminum hydroxide having >=450 deg.C dehydrating temperature and >=99 and <99.9 mass % purity in an atmosphere containing one kind of gas selected from (1) hydrogen chloride, (2) a component prepared from molecular chlorine and water vapor and (3) molecular chlorine at a temperature within the range of >=800 and <=1,200 deg.C. The method for producing theα-alumina particle comprises hydrothermally treating aluminum hydroxide having >=99 and <99.9 mass % purity at a temperature within the range of >=120 and <=300 deg.C and providing the aluminum hydroxide.