Patent FR497371A successfully refreshed from Google Patents.
US4497785A
Expired / Lapsed
US
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Production of rare earth compounds
Assignee: Union Oil Company of California
•
Filing: 1983-11-18
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Granted: 1985-02-05
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Expires: 2003-11-18
Abstract
Abstract A method for preparing high-density particles of rare earth carbonate comprises precipitating rare earth ions with aqueous carbonate or bicarbonate ions, in the presence of rare earth carbonate crystals, and separating the resulting precipitate. The method can be conducted to prepare individual batches or, alternatively, a continuous precipitation method can be used, wherein rare earth and carbonate or bicarbonate ions are mixed at a controlled rate to maintain an optimum pH condition. High-density rare earth oxide is obtained by calcining the precipitate.
Inventors
- 👤 George L. Tilley
- 👤 Allen W. Doty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:34
CPC Classifications
C; C01; C01F; C01F17/00; C01F17/20; C01F17/247; C01F17/206; C01F17/224; C01P; C01P2004/00; C01P2004/01; C01P2006/00; C01P2006/10
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
47 words
A method for preparing high-density rare earth carbonate which comprises admixing, with agitation, an aqueous solution containing rare earth ions and an aqueous solution containing bicarbonate or carbonate ions, in the presence of added rare earth carbonate crystals, and separating rare earth carbonate from the aqueous solution.
Claim 2
Independent Claim
47 words
A method for preparing high-density rare earth carbonate which comprises admixing, with agitation, an aqueous solution containing rare earth ions and an aqueous solution containing bicarbonate or carbonate ions, in the presence of added rare earth carbonate crystals, and separating rare earth carbonate from the aqueous solution.
Claim 3
Dependent Claim
25 words
The method defined in claim 1, wherein the pH of the solution of rare earth ions is adjusted to a value greater than about 3.
Claim 4
Dependent Claim
31 words
The method defined in claim 1, wherein rare earth carbonate crystals are added to the solution of rare earth ions, prior to admixing with the solution of bicarbonate or carbonate ions.
Claim 5
Dependent Claim
30 words
The method defined in claim 3, wherein added rare earth carbonate crystals have a concentration about 1 to about 70 grams per liter in the solution of rare earth ions.
Claim 6
Dependent Claim
25 words
The method defined in claim 1, wherein the concentration of rare earth ions in their aqueous solution is about 0.05 Molar to about 1 Molar.
Claim 7
Dependent Claim
26 words
The method defined in claim 1, wherein the concentration of bicarbonate or carbonate ions in their aqueous solution is about 0.05 Molar to about 4 Molar.
Claim 8
Dependent Claim
21 words
The method defined in claim 1, wherein temperatures about 30° C. to about 90° C. are maintained while solutions are admixed.
Claim 9
Dependent Claim
21 words
The method defined in claim 1, wherein added rare earth carbonate crystals have been prepared by the method of claim 1.
Claim 10
Dependent Claim
27 words
The method defined in claim 8, wherein a portion of the crystals has been present during one or more previous repetitions of the method of claim 1.
Claim 11
Dependent Claim
17 words
The method defined in claim 9, wherein the portion has been present during at least 3 repetitions.
Claim 12
Dependent Claim
64 words
The method defined in claim 1, wherein added rare earth carbonate crystals have been prepared by a method comprising admixing an aqueous solution containing rare earth ions and an aqueous solution containing bicarbonate or carbonate ions, while maintaining temperature about 30° C. to about 90° C., aging the admixture for at least about 4 hours, and separating rare earth carbonate from the aqueous solution.
Claim 13
Dependent Claim
46 words
The method defined in claim 1, wherein individual flows of rare earth ion solution and bicarbonate or carbonate ion solution are simultaneously introduced into a mixing vessel, at flow rates such that pH values about 4.5 to about 6 are maintained in the vessel during admixing.
Claim 14
Dependent Claim
12 words
The method defined in claim 1, wherein the rare earth is samarium.
Claim 15
Independent Claim
57 words
A method for preparing high-density rare earth oxide which comprises admixing, with agitation, an aqueous solution containing rare earth ions and an aqueous solution containing bicarbonate or carbonate ions, in the presence of added rare earth carbonate crystals, separating rare earth carbonate from the aqueous solution, and calcining the rare earth carbonate to form rare earth oxide.
Claim 16
Independent Claim
57 words
A method for preparing high-density rare earth oxide which comprises admixing, with agitation, an aqueous solution containing rare earth ions and an aqueous solution containing bicarbonate or carbonate ions, in the presence of added rare earth carbonate crystals, separating rare earth carbonate from the aqueous solution, and calcining the rare earth carbonate to form rare earth oxide.
Claim 17
Dependent Claim
28 words
The method defined in claim 14, wherein the pH of the solution of rare earth ions is adjusted to a value greater than about 3 prior to admixing.
Claim 18
Dependent Claim
31 words
The method defined in claim 14, wherein rare earth carbonate crystals are added to the solution of rare earth ions, prior to admixing with the solution of bicarbonate or carbonate ions.
Claim 19
Dependent Claim
30 words
The method defined in claim 16, wherein added rare earth carbonate crystals have a concentration about 1 to about 70 grams per liter in the solution of rare earth ions.
Claim 20
Dependent Claim
25 words
The method defined in claim 14, wherein the concentration of rare earth ions in their aqueous solution is about 0.05 Molar to about 1 Molar.
Claim 21
Dependent Claim
26 words
The method defined in claim 14, wherein the concentration of bicarbonate or carbonate ions in their aqueous solution is about 0.05 Molar to about 4 Molar.
Claim 22
Dependent Claim
21 words
The method defined in claim 14, wherein temperatures about 30° C. to about 90° C. are maintained while solutions are admixed.
Claim 23
Dependent Claim
21 words
The method defined in claim 14, wherein added rare earth carbonate crystals have been prepared by the method of claim 14.
Claim 24
Dependent Claim
27 words
The method defined in claim 21, wherein a portion of the crystals has been present during one or more previous repetitions of the method of claim 14.
Claim 25
Dependent Claim
17 words
The method defined in claim 22, wherein the portion has been present during at least 3 repetitions.
Claim 26
Dependent Claim
64 words
The method defined in claim 14, wherein added rare earth carbonate crystals have been prepared by a method comprising admixing an aqueous solution containing rare earth ions and an aqueous solution containing bicarbonate or carbonate ions, while maintaining temperatures about 30° C. to about 90° C., aging the admixture for at least about 4 hours, and separating rare earth carbonate from the aqueous solution.
Claim 27
Dependent Claim
46 words
The method defined in claim 14, wherein individual flows of rare earth ion solution and bicarbonate or carbonate ion solution are simultaneously introduced into a mixing vessel, at flow rates such that pH values about 4.5 to about 6 are maintained in the vessel during admixing.
Claim 28
Dependent Claim
12 words
The method defined in claim 14, wherein the rare earth is samarium.
Claim 29
Dependent Claim
18 words
The method defined in claim 14, wherein calcining is at temperatures about 900° C. to about 1500° C.
Claim 30
Independent Claim
50 words
A method for preparing high-density samarium oxide which comprises admixing, with agitation, an aqueous solution containing samarium ions and an aqueous solution containing bicarbonate or carbonate ions, in the presence of added samarium carbonate crystals, separating samarium carbonate from the aqueous solution, and calcining samarium carbonate to form samarium oxide.
Claim 31
Independent Claim
50 words
A method for preparing high-density samarium oxide which comprises admixing, with agitation, an aqueous solution containing samarium ions and an aqueous solution containing bicarbonate or carbonate ions, in the presence of added samarium carbonate crystals, separating samarium carbonate from the aqueous solution, and calcining samarium carbonate to form samarium oxide.
Claim 32
Dependent Claim
42 words
The method defined in claim 28, wherein the pH of the solution containing samarium ions is adjusted to a value about 3 to about 4, and samarium carbonate crystals are added, prior to admixing with the solution containing bicarbonate or carbonate ions.
Claim 33
Dependent Claim
28 words
The method defined in claim 29, wherein added rare earth crystals have a concentration about 1 to about 70 grams per liter in the solution containing samarium ions.
Claim 34
Dependent Claim
24 words
The method defined in claim 28, wherein the concentration of samarium ions in their aqueous solution is about 0.05 Molar to about 1 Molar.
Claim 35
Dependent Claim
26 words
The method defined in claim 28, wherein the concentration of bicarbonate or carbonate ions in their aqueous solution is about 0.05 Molar to about 4 Molar.
Claim 36
Dependent Claim
21 words
The method defined in claim 28, wherein temperatures about 30° C. to about 90° C. are maintained while solutions are admixed.
Claim 37
Dependent Claim
20 words
The method defined in claim 28, wherein added samarium carbonate crystals have been prepared by the method of claim 28.
Claim 38
Dependent Claim
27 words
The method defined in claim 34, wherein a portion of the crystals has been present during one or more previous repetitions of the method of claim 28.
Claim 39
Dependent Claim
17 words
The method defined in claim 35, wherein the portion has been present during at least 3 repetitions.
Claim 40
Dependent Claim
35 words
The method defined in claim 34, wherein, in the preparation of added crystals, the samarium carbonate is aged in its mother liquor for at least about 4 hours, prior to separating from the aqueous solution.
Claim 41
Dependent Claim
45 words
The method defined in claim 28, wherein individual flows of samarium ion solution and bicarbonate or carbonate ion solution are simultaneously introduced into a mixing vessel, at flow rates such that pH values about 4.5 to about 6 are maintained in the vessel during admixing.
Claim 42
Dependent Claim
16 words
The method defined in claim 38, wherein pH values about 4.9 to about 5.3 are maintained.
Claim 43
Dependent Claim
18 words
The method defined in claim 28, wherein calcining is at temperatures about 900° C. to about 1500° C.
Claim 44
Dependent Claim
16 words
The method defined in claim 40, wherein calcining is at temperatures greater than about 1000° C.
Claim 45
Independent Claim
115 words
A method for preparing high-density samarium oxide, comprising the steps of: (a) adjusting the pH of an aqueous solution containing samarium ions to a value about 3 to about 4; (b) adding samarium carbonate crystals to the samarium ion solution, in such amount as to form a slurry containing about 5 to about 50 grams per liter crystals; (c) while maintaining temperatures about 30° C. to about 90° C. and agitating the slurry, admixing the slurry with sufficient aqueous solution containing bicarbonate or carbonate ions to produce a pH about 6; (d) separating samarium carbonate from the aqueous solution; and (e) calcining the separated samarium carbonate at temperature about 1000° C. to about 1300° C.
Claim 46
Independent Claim
115 words
A method for preparing high-density samarium oxide, comprising the steps of: (a) adjusting the pH of an aqueous solution containing samarium ions to a value about 3 to about 4; (b) adding samarium carbonate crystals to the samarium ion solution, in such amount as to form a slurry containing about 5 to about 50 grams per liter crystals; (c) while maintaining temperatures about 30° C. to about 90° C. and agitating the slurry, admixing the slurry with sufficient aqueous solution containing bicarbonate or carbonate ions to produce a pH about 6; (d) separating samarium carbonate from the aqueous solution; and (e) calcining the separated samarium carbonate at temperature about 1000° C. to about 1300° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-05 | 1988-08-06 | 1989-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-05 | 1992-08-06 | 1993-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-05 | 1996-08-06 | 1997-02-05 | $7700.00 | Window Closed / Lapsed |