Patent US2659660A successfully refreshed from Google Patents.
US2659660A
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Method and apparatus for the manufacture of alumina
Assignee: Societe dElectro Chimie dElectro Metallurgie et des Acieries Electriques Dugine SA SECEMAU
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Filing: 1951-11-16
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Granted: 1953-11-17
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Expires: 1971-11-16
Abstract
No abstract record available.
Inventors
- 👤 Sable Andre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:46
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/46; C01F7/44; C01F7/441; C01P; C01P2002/00; C01P2002/30; C01P2002/70
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
66 words
A PROCESS FOR TREATING A SODA-CONTAMINATED MONOCLINIC ALUMINA HYDRATE AS OBTAINED FROM BAYER PROCESS PRIOR TO CALCINATION COMPRISING HEATING THE IMPURE ALUMINA ABOVE 180* C. WITH WATER UNDER PRESSURE TO DECOMPOSE THE MONOCLINIC CRYSTALS AND RECRYSTALLIZE THE ALUMINA AS A RHOMBOHEDRAL ALUMINA AND THEREBY TO FREE SODA AS A RESULT OF THE CHANGE IN OBTAINED, STRUCTURE, SEPARATING THE ALUMINA THUS OBTAINED, AND RECOVERING THE RESULTING ALUMINA.
Claim 2
Dependent Claim
66 words
A PROCESS FOR TREATING A SODA-CONTAMINATED MONOCLINIC ALUMINA HYDRATE AS OBTAINED FROM BAYER PROCESS PRIOR TO CALCINATION COMPRISING HEATING THE IMPURE ALUMINA ABOVE 180* C. WITH WATER UNDER PRESSURE TO DECOMPOSE THE MONOCLINIC CRYSTALS AND RECRYSTALLIZE THE ALUMINA AS A RHOMBOHEDRAL ALUMINA AND THEREBY TO FREE SODA AS A RESULT OF THE CHANGE IN OBTAINED, STRUCTURE, SEPARATING THE ALUMINA THUS OBTAINED, AND RECOVERING THE RESULTING ALUMINA.
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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) | 1956-11-16 | 1957-05-18 | 1957-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-11-16 | 1961-05-18 | 1961-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-11-16 | 1965-05-18 | 1965-11-17 | $7700.00 | Window Closed / Lapsed |