Patent US2792719A successfully refreshed from Google Patents.
US3012877A
Expired / Lapsed
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Method of producing columbium and tantalum
Assignee: Millennium Petrochemicals Inc
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Filing: 1958-06-20
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Granted: 1961-12-12
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Expires: 1978-06-20
Abstract
No abstract record available.
Inventors
- 👤 Raymond A Foos
- 👤 Robert L Maddox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:41
CPC Classifications
C; C22; C22B; C22B34/00; C22B34/20; C22B34/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
25 words
A CONTINUOUS METHOD FOR PRODUCING A METAL SELECTED FROM THE GROUP CONSISTING OF COLUMBIUM AND TANTALUM FROM A DOUBLE FLUORIDE SALT THEREOF HAVING THE FORMULA
Claim 2
Dependent Claim
25 words
A CONTINUOUS METHOD FOR PRODUCING A METAL SELECTED FROM THE GROUP CONSISTING OF COLUMBIUM AND TANTALUM FROM A DOUBLE FLUORIDE SALT THEREOF HAVING THE FORMULA
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) | 1964-12-11 | 1965-06-12 | 1965-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-12-11 | 1969-06-12 | 1969-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-12-11 | 1973-06-12 | 1973-12-12 | $7700.00 | Window Closed / Lapsed |