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Patent US2980496A successfully refreshed from Google Patents.
US2980496A
Expired / Lapsed
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Process for purifying fluoride-contaminated columbium and tantalum compounds
Assignee: Union Carbide Corp
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Filing: 1957-12-24
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Granted: 1961-04-18
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Expires: 1977-12-24
Abstract
No abstract record available.
Inventors
- 👤 Jr John D Mettler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:04
CPC Classifications
C; C01; C01G; C01G33/00; C01P; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
79 words
A PROCESS FOR PURIFYING FLUORIDE-CONTAMINATED TANTALUM PENTOXIDE WHICH COMPRISES REDUCING THE FLUORIDE CONTENT OF SAID FLUORIDE-CONTAMINED TANTALUM PENTOXIDE TO BELOW ABOUT 4 WEIGHT PERCENT BY WASHING SAID PENTOXIDE WITH WATER, SUBSTANTIALLY DRYING THE WASHED PENTOXIDE WITHOUT SUBSTANTIAL EVOLUTION OF GASEOUS FLUORINE COMPOUNDS, AND CALCINING THE DRIED PENTOXIDE AT A TEMPERATURE OF AT LEAST ABOUT 1000*C. IN A CARBON MONOXIDE ATMOSPHERE IN A GRAPHITE IS REDUCED BELOW ABOUT 0.1 TAMINATION OF THE PENTOXIDE IS REDUCED BELOW ABOUT 0.1 WEIGHT PERCENT.
Claim 2
Dependent Claim
79 words
A PROCESS FOR PURIFYING FLUORIDE-CONTAMINATED TANTALUM PENTOXIDE WHICH COMPRISES REDUCING THE FLUORIDE CONTENT OF SAID FLUORIDE-CONTAMINED TANTALUM PENTOXIDE TO BELOW ABOUT 4 WEIGHT PERCENT BY WASHING SAID PENTOXIDE WITH WATER, SUBSTANTIALLY DRYING THE WASHED PENTOXIDE WITHOUT SUBSTANTIAL EVOLUTION OF GASEOUS FLUORINE COMPOUNDS, AND CALCINING THE DRIED PENTOXIDE AT A TEMPERATURE OF AT LEAST ABOUT 1000*C. IN A CARBON MONOXIDE ATMOSPHERE IN A GRAPHITE IS REDUCED BELOW ABOUT 0.1 TAMINATION OF THE PENTOXIDE IS REDUCED BELOW ABOUT 0.1 WEIGHT PERCENT.
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) | 1964-04-17 | 1964-10-17 | 1965-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-17 | 1968-10-17 | 1969-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-17 | 1972-10-17 | 1973-04-18 | $7700.00 | Window Closed / Lapsed |