US2451492A
Expired / Lapsed
US
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Method and apparatus for enriching the alumina content of cryolite fusions in aluminum production
Assignee: Reynolds Metals Co
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Filing: 1946-01-31
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Granted: 1948-10-19
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Expires: 1966-01-31
Abstract
No abstract record available.
Inventors
- 👤 Arthur F Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:56
CPC Classifications
C; C25; C25C; C25C3/00; C25C3/06; C25C3/18; C25C3/08
Claims Analysis
Total Claims: 0
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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) | 1951-10-19 | 1952-04-19 | 1952-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-10-19 | 1956-04-19 | 1956-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-10-19 | 1960-04-19 | 1960-10-19 | $7700.00 | Window Closed / Lapsed |