PRODUCTION OF FINE POWDER WITH FLOCCULATION SUPPRESSED

摘要

PROBLEM TO BE SOLVED: To obtain a hydroxide or oxide-base superfine powder which is never flocculated with a convenient technique. SOLUTION: An aq. soln. contg. one or >=2 kinds of metal ions capable of flocculating a hydroxide precipitate in the presence of sulfate ion is allowed to react with a hydroxide-base precipitant to crystallize the precipitate. In this case, sulfate ion is added before or after the precipitate is crystallized to flocculate the formed precipitate. The precipitate is then dispersed in an org. solvent without being dried and dried to form the individually separated amorphous or crystalline primary particles having <=0.2μm average diameter.