US4044115A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of alumina monohydrate from aluminum nitrate solutions
Assignee: United States Department of the Interior
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Filing: 1976-07-02
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Granted: 1977-08-23
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Expires: 1996-07-02
Abstract
Abstract Alumina monohydrate is produced by treating aluminum nitrate solution at a temperature of about 250° to 350° C and a pressure of about 500 to 2500 psig.
Inventors
- 👤 Judith A. Eisele
- 👤 Barlane R. Eichbaum
- 👤 Donald J. Bauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:34
CPC Classifications
C; C01; C01D; C01D7/00; C01D7/22; C01D7/34; C01F; C01F7/00; C01F7/02; C01F7/34
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
69 words
A method for production of alumina monohydrate consisting of treating an aqueous solution of aluminum nitrate containing about 0.5 to 7.2 weight percent aluminum at a temperature of about 250° to 350° C and a pressure of about 500 to 2500 psig for a time sufficient to convert a major proportion of the nitrate to monohydrate, cooling the reaction mixture to room temperature and separating the precipitated alumina monohydrate.
Claim 2
Independent Claim
69 words
A method for production of alumina monohydrate consisting of treating an aqueous solution of aluminum nitrate containing about 0.5 to 7.2 weight percent aluminum at a temperature of about 250° to 350° C and a pressure of about 500 to 2500 psig for a time sufficient to convert a major proportion of the nitrate to monohydrate, cooling the reaction mixture to room temperature and separating the precipitated alumina monohydrate.
Claim 3
Dependent Claim
16 words
The method of claim 1 in which the reaction time is about one to six hours.
Claim 4
Dependent Claim
26 words
The method of claim 1 in which the reaction temperature is about 275° C, the pressure is about 950psig, and reaction time is about 4 hours.
References Cited (Backward Citations)
GB367525A
Cited
US2737445A
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US3366446A
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US3864462A
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US3647373A
Cited
US3869543A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-22 | 1981-02-21 | 1981-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-22 | 1985-02-21 | 1985-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-22 | 1989-02-21 | 1989-08-23 | $7700.00 | Window Closed / Lapsed |