Patent US3579294A successfully refreshed from Google Patents.
US3579294A
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US
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Process for extraction of alumina from ores by solution of caustic soda and sodium aluminate
Assignee: Pechiney SA
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Filing: 1968-03-15
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Granted: 1971-05-18
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Expires: 1988-03-15
Abstract
Abstract PROCESS AND EQUIPMENT FOR THE CONTINUOUS EXTRACTION OF ALUMINA FROM BAUXITE BY DISSOLUTION IN AQUEOUS CAUSTIC SODA AND SODIUM ALUMINATE SOLUTIONS IN WHICH USE IS MADE OF A PLURALITY OF AUTOCLAVES OF INCREASING TEMPERATURE THROUGH WHICH THE SUSPENSION FLOWS IN SERIES FROM ONE TO THE NEXT IN A SEQUENCE OF STAGES AND A PLURALITY OF EXPANSION VESSELS OF DECREASING PRESSURE IN SERIES WITH THE AUTOCLAVES AND THROUGH WHICH THE SUSPENSION FLOWS IN SERIES.
Inventors
- 👤 Louis Tamise
- 👤 Jacques Millet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:41
CPC Classifications
B; B01; B01D; B01D1/00; B01D1/06; B01D1/10; B01D1/065; C; C01; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/06; C01F7/066
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |