PRODUCTION OF FINE POWDER OF CERAMIC RAW MATERIAL

摘要

PURPOSE:To obtain the title fine powder having uniform and small particle diameter by dripping an aqueous solution containing an alkaline earth metal and Ti and/or Zr into an aqueous solution containing oxalate ion and NH4 ion and burning the formed precipitate. CONSTITUTION:An aqueous solution containing one or more alkaline earth metals (e.g. chloride) and Ti (e.g. titanium tetrachloride) and/or Zr (e.g. zirconium oxychloride) at pH <=2 is dripped into an aqueous solution containing oxalate ion (e.g. ammonium oxalate) and NH4 ion (e.g. ammonium oxalate and concentrated ammonia water) at pH7-12 while stirring by a static mixer at about 1-2m/second flow velocity. The slurry has pH3-11 after completion of the dripping. The slurry is filtered, the precipitate is cleaned with ion exchange water and dried by hot air at 50 deg.C. The prepared ceramic crystal particles having a given composition are sintered at 800-1,200 deg.C for 2-10 hours to give ceramic raw material fine powder comprising primary particles having 0.1-1.0mum average particle diameter.