Claims
- 1. A method for manufacturing rare earth oxide voidless spherical grains having a mean grain diameter of from about 20-300 .mu.m comprising the steps of slurrying a rare earth oxide powder having a mean particle diameter of about 1 .mu.m or less by dispersing it in water, admixing a salt of an organic acid in an amount from about 0.01 to 1.00 weight part per 100 weight parts of rare earth oxide with the slurry, and spray-drying the slurry.
- 2. The method of claim 1 wherein said rare earth oxide powder has a mean particle diameter of about 0.8 to 1.0 .mu.m.
- 3. The method of claim 1 wherein said rare earth oxide is selected from the group consisting of oxides of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, or Sc, and mixtures thereof.
- 4. The method of claim 1 wherein said organic acid salt is selected from the group consisting of sodium alginate, ammonium alginate, sodium carboxymethyl cellulose, or ammonium carboxymethyl cellulose, and mixtures thereof.
- 5. The method of claim 1 wherein the dosage of said salt is from about 0.01 to 1.00 weight part per 100 weight parts of rare earth oxide.
- 6. The method of claim 1 wherein said rare earth oxide powder is Y.sub.2 O.sub.3.
- 7. The method of claim 1 wherein said rare earth oxide powder is Gd.sub.2 O.sub.3.
- 8. The method of claim 1 wherein said rare earth oxide powder is Er.sub.2 O.sub.3.
- 9. The method of claim 1 wherein said rare earth oxide voidless spherical grains have a mean grain diameter of 20-80 .mu.m.
- 10. The method of claim 1 wherein said grains have a bulk density from about 1.2 to 2 g/cc.
Priority Claims (1)
Number |
Date |
Country |
Kind |
1-153728 |
Jun 1989 |
JPX |
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Parent Case Info
This is a division of application Ser. No. 07/539,064, filed June 15, 1990, now U.S. Pat. No. 5,061,560.
US Referenced Citations (7)
Foreign Referenced Citations (4)
Number |
Date |
Country |
6729965 |
Dec 1965 |
AUX |
255353 |
Oct 1988 |
JPX |
966945 |
Aug 1964 |
GBX |
8704110 |
Jul 1987 |
WOX |
Non-Patent Literature Citations (4)
Entry |
Ludwig, "How & Why Solids Agglomerate", Jan. 1954. |
Wrich, "Chemical Processing of Ceramics", Jan. 1, 1990, E & EN. |
Hoffman, "Importance of Binders in Spray Dried Pressbodies", Ceramic Bulletin, Jun. 26, 1971. |
Porovkova, "The Sintering & Properties of Y.sub.2 O.sub.3 Compounds", Nov. 1970. |
Divisions (1)
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Number |
Date |
Country |
Parent |
539064 |
Jun 1990 |
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