Patent US3666731A successfully refreshed from Google Patents.
US2668751A
Expired / Lapsed
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Process for production of alumina
Assignee: Kaiser Aluminum and Chemical Corp
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Filing: 1949-12-30
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Granted: 1954-02-09
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Expires: 1969-12-30
Abstract
No abstract record available.
Inventors
- 👤 John L Porter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:35
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/06; C01F7/0613
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
94 words
IN A PROCESS FOR THE EXTRACTION OF ALUMINA FROM ALUMINOUS ORES CONTAINING MIXTURES OF TRIHYDRATE AND MONOHYDRATE ALUMINA WHEREIN THE MAJOR PORTION OF THE TOTAL AVAILABLE ALUMINA IS TRIHYDRATE BY THE WET ALKALI ALUMINATE DIGESTION METHOD WHEREIN SUBSTANTIALLY ALL OF THE TRIHYDRATE AND ONLY A PORTION OF THE MONOHYDRATE ALUMINA IS EXTRACTED, THE IMPROVEMENT OF INHIBITING REVERSION OF SOLUBLE ALUMINA TO INSOLUBLE MONOHYDRATE ALUMINA, WHICH COMPRISES CALCINING THE ORE TO A RESIDUAL IGNITION LOSS OF FROM ABOUT 2 TO ABOUT 5% BY WEIGHT OF THE ORE PRIOR TO DIGESTION IN THE CAUSTIC ALUMINATE LIQUOR.
Claim 2
Dependent Claim
94 words
IN A PROCESS FOR THE EXTRACTION OF ALUMINA FROM ALUMINOUS ORES CONTAINING MIXTURES OF TRIHYDRATE AND MONOHYDRATE ALUMINA WHEREIN THE MAJOR PORTION OF THE TOTAL AVAILABLE ALUMINA IS TRIHYDRATE BY THE WET ALKALI ALUMINATE DIGESTION METHOD WHEREIN SUBSTANTIALLY ALL OF THE TRIHYDRATE AND ONLY A PORTION OF THE MONOHYDRATE ALUMINA IS EXTRACTED, THE IMPROVEMENT OF INHIBITING REVERSION OF SOLUBLE ALUMINA TO INSOLUBLE MONOHYDRATE ALUMINA, WHICH COMPRISES CALCINING THE ORE TO A RESIDUAL IGNITION LOSS OF FROM ABOUT 2 TO ABOUT 5% BY WEIGHT OF THE ORE PRIOR TO DIGESTION IN THE CAUSTIC ALUMINATE LIQUOR.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-02-08 | 1957-08-10 | 1958-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-02-08 | 1961-08-10 | 1962-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-02-08 | 1965-08-10 | 1966-02-09 | $7700.00 | Window Closed / Lapsed |