| 摘要 |
PURPOSE:To produce easily sintering alumina powder having small particle diameter at a low cost, by adding alpha-alumina powder to an aluminum salt or hydrated alumina which gives alumina by thermal decomposition, calcining the mixture and pulverizing the product. CONSTITUTION:A starting raw material for alumina is added with alpha-alumina powder and the mixture is calcined and pulverized to obtain the objective alumina powder. The starting raw material used in the above process is selected from an aluminum salt giving alumina by thermal decomposition (e.g. ammonium alum), a hydrated alumina obtained by the hydrolysis of an organoaluminum compound such as alkylaluminum, a hydrated alumina produced by the spark discharge of aluminum in water and a hydrated alumina produced by reacting an aqueous solution of sodium aluminate with ethylene chlorohydrin. The amount of the alpha-alumina is preferably 0.1-50pts.wt. per 100pts.wt. of the starting raw material and the particle diameter of the powder is preferably <=1.0mum.
|
