METHOD OF PRODUCING ALUMINA POWDER

PROBLEM TO BE SOLVED: To provide a method by which fine alumina powder of high purity can be produced by a thermal decomposition method of aluminum chloride.SOLUTION: A method of producing alumina powder by thermally decomposing aluminum chloride hexahydrate is provided. In the method, the alumina powder which is easy to crush can be obtained by thermally decomposing the aluminum chloride hexahydrate under a condition of an average decomposition speed of 3-15 mass%/hr represented by following expression until the decomposition rate reaches 80 mass%, thereby the fine and high purity alumina powder extremely little contaminated due to crushing is efficiently produced. Here, average decomposition speed (mass%/hr)=decomposition rate (mass%)/decomposition hours (hr).