PRODUCTION OF ALPHA-ALUMINA POWDER HAVING LOW VISCOSITY

摘要

PURPOSE:To lower the slurry viscosity of alpha-alumina and suppress the variation of the viscosity with time, by heat-treating fine powder of alpha-alumina at a specific temperature, thereby suppressing the activity of the surface. CONSTITUTION:Fine powder of alpha-alumina produced by dry-pulverization is heat-treated at a temperature between 300 deg.C and the calcination temperature of alpha-alumina. The surface activity of alumina increased by the dry-pulverization can be lowered by the heat-treatment. An aqueous or organic slurry of alumina produced by using the treated alumina powder has a viscosity and viscosity change with time suppressed to low levels independent of the kind and amount of the dispersant, etc., added to the slurry.