PREPARATION OF FINE POWDERY YTTRIUM OXIDE

摘要

PURPOSE:To obtain fine powdery yttrium oxide having small average particle size and a narrow range of particle size distribution by roasting a basic salt of yttrium having a specified composition. CONSTITUTION:A basic salt of yttrium expressed by the formula (wherein X is Cl or NO3) is roasted. The basic salt of yttrium to be used is obtd. by dropping aq. soln. of alkali (e.g. aq. NH3 aq. NaOH) into aq. soln. of a yttrium salt (e.g. yttrium chloride yttrium nitrate) while regulating the pH of the soln. to <=8, particulary pref. to <=7.5. The shape of particles of obtd. basic salt of yttrium is flaky. The basic yttrium salt has a characteristic property that the roasted product causes no coagulation even if it is intentionally coagulated by press- forming before roasting.