MANUFACTURE OF MULLITE POWDER AND MULLITE-ALUMINA MIXED POWDER

摘要

PURPOSE:To manufacture mullite powder or mullite-alumina mixed powder contg. no residual silica by hydrothermally treating a mixture of fine alumina powder or a dispersion of the powder with fine silica powder or a dispersion of the powder and carrying out calcination. CONSTITUTION:Alumina powder having =1mum average particle size or a dispersion of the powder is mixed with silica powder having =1mum average particle size or a dipersion of the powder so as to make the atomic ratio of A/Si =about 2. Hot water regulated to high temp. and pressure is allowed to act on the mixture, and the resulting powdered precipitate is taken out by filtration, dried, and calcined to manufacture mullite powder or mullite-alumina mixed powder contg. no residual unreacted silica.