| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide stabilized zirconia fine powder which has a reduced alkali metal content and a sulfuric acid radical content, and to provide a method for producing the same by which the amount of ammonia components included in industrial waste water to be exhausted can remarkably be reduced. <P>SOLUTION: The zirconia fine powder has a composition containing stabilizing elements selected from Y, Ca, Mg, Al and rare earth elements, and in which the content of the alkali metal is ≤100 ppm, and the content of sulfuric acid radicals is ≤250 ppm. The zirconia fine powder has a crystallite diameter of ≤50 nm, a bulk density of ≥0.80 g/cm<SP>3</SP>, a tap density of ≥1.30 g/cm<SP>3</SP>and a tetragonal ratio of ≥90%. The stabilized zirconia fine powder is obtained by increasing the temperature of an aqueous solution containing the stabilizing elements, sulfuric acid radicals and zirconium to ≥50°C to precipitate zirconium basic sulfate, and adding the hydroxide of the alkali metal to the slurry to control the pH therein to ≥8, and performing filtering to obtain a zirconium hydroxide aggregate with the stabilizing elements fixed, and roasting the aggregate. <P>COPYRIGHT: (C)2003,JPO |
