US2657978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alumina hydrate crystallization
Assignee: Kaiser Aluminum and Chemical Corp
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Filing: 1948-09-08
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Granted: 1953-11-03
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Expires: 1968-09-08
Abstract
No abstract record available.
Inventors
- 👤 Martin A Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:13
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/14; C01F7/144; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/21
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
175 words
IN A PROCESS OF CRYSTALLIZING ALUMINA HYDRATE FROM A BODY OF CAUSTIC LIQUOR SUPERSATURATED WITH RESPECT TO SODIUM ALUMINATE, THE IMPROVEMENT WHICH COMPRISES, ADDING A FIRST QUANTITY OF ALUMINA HYDRATE SEED CRYSTALS TO THE LIQUOR IN AN AMOUNT EQUAL TO FROM ABOUT 25 TO NOT MORE THAN ABOUT 50% OF THE TOTAL QUANTITY OF SEED EMPLOYED ON THE SAID BODY OF LIQUOR, AGITATING THE LIQUOR CONTAINING THE FIRST QUANTITY OF SEED FOR A PERIOD OF TIME AFTER ADDITION OF ALL OF SAID FIRST QUANTITY OF SEED FROM ABOUT 30 TO ABOUT 55% OF THE TOTAL CRYSTALIZATION PERIOD AND BEFORE THE ADDITION OF THE BALANCE OF THE TOTAL QUANTITY OF SEED, WHEREBY THE ALUMINA HYDRATE THUS OBTAINED IS CHARACTERIZED BY PREDOMINANTLY COARSE CRYSTALS OF CALCINATION GRADE WITH A MINIMUM OF FINES, AND THEREAFTER MAKING A SECOND ADDITION TO THE BODY OF THE LIQUOR OF THE BALANCE OF THE ALUMINA HYDRATE SEED TO INCREASE THE RATE LOF PRECIPITATION OF ALUMINA HYDRATE IN THE FORM OF A FRACTION SUBSTANTIALLY ALL OF WHICH COMPRISES FINE CRYSTALS OF SEED GRADE.
Claim 2
Dependent Claim
175 words
IN A PROCESS OF CRYSTALLIZING ALUMINA HYDRATE FROM A BODY OF CAUSTIC LIQUOR SUPERSATURATED WITH RESPECT TO SODIUM ALUMINATE, THE IMPROVEMENT WHICH COMPRISES, ADDING A FIRST QUANTITY OF ALUMINA HYDRATE SEED CRYSTALS TO THE LIQUOR IN AN AMOUNT EQUAL TO FROM ABOUT 25 TO NOT MORE THAN ABOUT 50% OF THE TOTAL QUANTITY OF SEED EMPLOYED ON THE SAID BODY OF LIQUOR, AGITATING THE LIQUOR CONTAINING THE FIRST QUANTITY OF SEED FOR A PERIOD OF TIME AFTER ADDITION OF ALL OF SAID FIRST QUANTITY OF SEED FROM ABOUT 30 TO ABOUT 55% OF THE TOTAL CRYSTALIZATION PERIOD AND BEFORE THE ADDITION OF THE BALANCE OF THE TOTAL QUANTITY OF SEED, WHEREBY THE ALUMINA HYDRATE THUS OBTAINED IS CHARACTERIZED BY PREDOMINANTLY COARSE CRYSTALS OF CALCINATION GRADE WITH A MINIMUM OF FINES, AND THEREAFTER MAKING A SECOND ADDITION TO THE BODY OF THE LIQUOR OF THE BALANCE OF THE ALUMINA HYDRATE SEED TO INCREASE THE RATE LOF PRECIPITATION OF ALUMINA HYDRATE IN THE FORM OF A FRACTION SUBSTANTIALLY ALL OF WHICH COMPRISES FINE CRYSTALS OF SEED GRADE.
References Cited (Backward Citations)
US1070438A
Cited
US1943786A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-11-02 | 1957-05-04 | 1957-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-11-02 | 1961-05-04 | 1961-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-11-02 | 1965-05-04 | 1965-11-03 | $7700.00 | Window Closed / Lapsed |