Patent US4057195A successfully refreshed from Google Patents.
Patent US3003867A successfully refreshed from Google Patents.
US3003867A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for recovery of niobium
Assignee: Gulf Research and Development Co
•
Filing: 1959-05-22
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Granted: 1961-10-10
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Expires: 1979-05-22
Abstract
No abstract record available.
Inventors
- 👤 Bernard J Lerner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:03
CPC Classifications
C; C22; C22B; C22B34/00; C22B34/20; C22B34/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
53 words
IN A PROCESS OF TREATING ORES CONTAINING NIOBIUM IN ASSOCIATION WITH ALKALINE EARTH METALS WITH SULFURIC ACID TO DECOMPOSE THE ORE AND TO RENDER THE NIOBIUM EXTRACTABLE FROM THE ORE WITH ORGANIC LEACHING AGENTS, THE IMPROVEMENT WHICH COMPRISES, UTILIZING SULFURIC ACID OF A CONCENTRATION FROM ABOUT 35 TO ABOUT 75 PERCENT BY WEIGHT.
Claim 2
Dependent Claim
53 words
IN A PROCESS OF TREATING ORES CONTAINING NIOBIUM IN ASSOCIATION WITH ALKALINE EARTH METALS WITH SULFURIC ACID TO DECOMPOSE THE ORE AND TO RENDER THE NIOBIUM EXTRACTABLE FROM THE ORE WITH ORGANIC LEACHING AGENTS, THE IMPROVEMENT WHICH COMPRISES, UTILIZING SULFURIC ACID OF A CONCENTRATION FROM ABOUT 35 TO ABOUT 75 PERCENT BY WEIGHT.
References Cited (Backward Citations)
US2259396A
Cited
US2481584A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-10-09 | 1965-04-10 | 1965-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-10-09 | 1969-04-10 | 1969-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-10-09 | 1973-04-10 | 1973-10-10 | $7700.00 | Window Closed / Lapsed |