Patent US4035468A successfully refreshed from Google Patents.
US4035468A
Expired / Lapsed
US
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Uranium dioxide process
Assignee: CAMECO AB
•
Filing: 1976-02-26
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Granted: 1977-07-12
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Expires: 1996-02-26
Abstract
Abstract Process for the preparation of fine particle size uranium dioxide from a uranium trioxide feed comprising the following steps:
Inventors
- 👤 William J. S. Craigen
- 👤 Tadeusz W. Zawidzki
- 👤 Bruce C. Smart
- 👤 Frank W. Melvanin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:02
CPC Classifications
C; C01; C01G; C01G43/00; C01G43/01; C01G43/025; C01P; C01P2006/00; C01P2006/10; C01P2006/12; C01P2006/80
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
74 words
Process for the preparation of fine particle size uranium dioxide from a uranium trioxide feed comprising the following steps: (a) reacting solid uranium trioxide with aqueous ammonium nitrate to form an insoluble ammonium uranate; (b) neutralizing the thus formed slurry with ammonium hydroxide to precipitate out as an insoluble ammonium uranate the remaining dissolved uranium; (c) recovering the thus formed precipitates in a dry state, and (d) reducing the dried precipitate to uranium dioxide.
Claim 2
Dependent Claim
74 words
Process for the preparation of fine particle size uranium dioxide from a uranium trioxide feed comprising the following steps: (a) reacting solid uranium trioxide with aqueous ammonium nitrate to form an insoluble ammonium uranate; (b) neutralizing the thus formed slurry with ammonium hydroxide to precipitate out as an insoluble ammonium uranate the remaining dissolved uranium; (c) recovering the thus formed precipitates in a dry state, and (d) reducing the dried precipitate to uranium dioxide.
Claim 3
Dependent Claim
8 words
Process according to claim 1 when operated batchwise.
Claim 4
Dependent Claim
8 words
Process according to claim 1 when operated continuously.
Claim 5
Dependent Claim
14 words
Process according to claim 1 wherein steps (a), (b), and (c) are operated batchwise.
Claim 6
Dependent Claim
14 words
Process according to claim 1 wherein steps (a), (b), and (c) are operated continuously.
Claim 7
Dependent Claim
21 words
Process according to claim 1 wherein ammonia released in step (d) is recycled to step (b) to provide the ammonium hydroxide.
Claim 8
Dependent Claim
27 words
Process according to claim 1 wherein the ammonium nitrate liquor remaining after recovering the insoluble ammonium uranate in step (c) is recycled for re-use in step (a).
Claim 9
Dependent Claim
24 words
Process according to claim 1 wherein the ammonium nitrate used in step (a) has a concentration from about 50 gm/liter to about 420 gm/liter.
Claim 10
Dependent Claim
21 words
Process according to claim 8 wherein the aqueous ammonium nitrate has a concentration from about 100 gm/liter to about 250 gm/liter.
Claim 11
Dependent Claim
22 words
Process according to claim 1 wherein step (a) is carried out at a temperature from about 25° C. to about 100° C.
Claim 12
Dependent Claim
17 words
Process according to claim 10 wherein the temperature is from about 60° C. to about 100° C.
Claim 13
Dependent Claim
25 words
Process according to claim 1 wherein the weight ratio of uranium trioxide to ammonium nitrate in step (a) is from about 0.5:1 to about 10:1.
Claim 14
Dependent Claim
19 words
Process according to claim 12 wherein the weight ratio of uranium dioxide to ammonium nitrate is below about 2:1.
Claim 15
Dependent Claim
14 words
Process according to claim 1 wherein the insoluble ammonium uranate is recovered by filtration.
Claim 16
Dependent Claim
13 words
Process according to claim 12 wherein the slurry is not cooled before filtration.
Claim 17
Dependent Claim
12 words
Process according to claim 14 wherein the filtered precipitate is water washed.
Claim 18
Dependent Claim
13 words
Process according to claim 14 wherein the filtered precipitate is hot water washed.
Claim 19
Dependent Claim
18 words
Process according to claim 1 wherein the reduction of step (d) is carried out in a hydrogen atmosphere.
Claim 20
Dependent Claim
12 words
Process according to claim 1 wherein step (c) includes a pelletizing operation.
Claim 21
Dependent Claim
18 words
Process according to claim 18 wherein the reduction is carried out at a temperature above about 400° C.
Claim 22
Dependent Claim
12 words
Process according to claim 15 wherein the filtered precipitate is water washed.
Claim 23
Dependent Claim
13 words
Process according to claim 15 wherein the filtered precipitate is hot water washed.
Claim 24
Dependent Claim
18 words
Process according to claim 19 wherein the reduction is carried out at a temperature above about 400° 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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |