Patent US3761211A successfully refreshed from Google Patents.
US2636044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rare earth separation by anion exchange
Assignee: Individual
•
Filing: 1951-06-22
•
Granted: 1953-04-21
•
Expires: 1971-06-22
Abstract
No abstract record available.
Inventors
- 👤 Eugene H Huffman
- 👤 Robert L Oswalt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:43
CPC Classifications
C; C01; C01F; C01F17/00; C01F17/10; C01F17/13
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
69 words
IN A METHOD FOR SEPARATING RARE EARTH ELEMENTS FROM EACH OTHER, THE STEPS COMPRISING ADSORBING RARE EARTH-CITRATE COMPLEXES FROM AN ACIDIC AQUEOUS CITRATE SOLUTION ON A STRONG BASE TYPE ANION EXCHANGE RESIN POSSESSING EXCHANGEABLE CITRATE ANIONS, AND SELECTIVELY ELUTING EACH ADSORBED RARE EARTH COMPLEX IN THE ORDER OF INCREASING RARE ATOMIC NUMBER WITH A CITRIC ACID SOLUTION HAVING A PH VALUE IN THE RANGE OF ABOUT 1.5 TO 3.0.
Claim 2
Dependent Claim
69 words
IN A METHOD FOR SEPARATING RARE EARTH ELEMENTS FROM EACH OTHER, THE STEPS COMPRISING ADSORBING RARE EARTH-CITRATE COMPLEXES FROM AN ACIDIC AQUEOUS CITRATE SOLUTION ON A STRONG BASE TYPE ANION EXCHANGE RESIN POSSESSING EXCHANGEABLE CITRATE ANIONS, AND SELECTIVELY ELUTING EACH ADSORBED RARE EARTH COMPLEX IN THE ORDER OF INCREASING RARE ATOMIC NUMBER WITH A CITRIC ACID SOLUTION HAVING A PH VALUE IN THE RANGE OF ABOUT 1.5 TO 3.0.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-04-20 | 1956-10-20 | 1957-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-04-20 | 1960-10-20 | 1961-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-04-20 | 1964-10-20 | 1965-04-21 | $7700.00 | Window Closed / Lapsed |