Patent US3275404A successfully refreshed from Google Patents.
US3275404A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for separating rare earth metal values
Assignee: Research Corp
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Filing: 1963-10-07
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Granted: 1966-09-27
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Expires: 1983-10-07
Abstract
No abstract record available.
Inventors
- 👤 Ferdinand H Firsching
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:42
CPC Classifications
C; C01; C01F; C01F17/00; C01F17/10; C01F17/20; C01F17/253
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
87 words
THE METHOD OF SEPARATING A RARE EARTH METAL VALUE FROM A SOLUTION CONTAINING ADDITIONAL RARE EARTH METAL VALUES WHICH COMPRISES: (A) ADDING TO SAID SOLUTION AT LEAST TWO POLYAMINOPOLYACETIC ACID RARE EARTH METAL SEQUESTERING AGENTS, (B) THEREAFTER ADDING AN ANION FORMING A RELATIVELY INSOLUBLE SALT WITH THE RARE EARTH METAL HAVING THE LEAST CHELATE STABILITY (C) FURTHER DECREASING THE SOLUBILITY OF THE RELATIVELY INSOLUBLE SALT BY THEN ADDING A CATIONIC REPLACING AGENT TO THE SOLUTION, AND (D) SEPARATING THE THUS FORMED PECIPATE OF THE RELATIVELY INSOLUBLE SALT.
Claim 2
Independent Claim
87 words
THE METHOD OF SEPARATING A RARE EARTH METAL VALUE FROM A SOLUTION CONTAINING ADDITIONAL RARE EARTH METAL VALUES WHICH COMPRISES: (A) ADDING TO SAID SOLUTION AT LEAST TWO POLYAMINOPOLYACETIC ACID RARE EARTH METAL SEQUESTERING AGENTS, (B) THEREAFTER ADDING AN ANION FORMING A RELATIVELY INSOLUBLE SALT WITH THE RARE EARTH METAL HAVING THE LEAST CHELATE STABILITY (C) FURTHER DECREASING THE SOLUBILITY OF THE RELATIVELY INSOLUBLE SALT BY THEN ADDING A CATIONIC REPLACING AGENT TO THE SOLUTION, AND (D) SEPARATING THE THUS FORMED PECIPATE OF THE RELATIVELY INSOLUBLE SALT.
Claim 3
Independent Claim
41 words
THE METHOD OF SEPARATING LANTHANUM AND PRASEO DYMIUM WHICH COMPRISES ADDING TO A SOLUTION CONTAINING LANTHANUM AND PRASEODYMIUM COMPLEXES WITH AT LEAST TWO POLYAMINOPOLYACETIC ACID SEQUESTERING AGENTS, CADMIUM CATION AND IODATE ANION, AND SEPARATING THE THUS FORMED PECIPITATE OF LANTHANUM IODATE.
Claim 4
Independent Claim
41 words
THE METHOD OF SEPARATING LANTHANUM AND PRASEO DYMIUM WHICH COMPRISES ADDING TO A SOLUTION CONTAINING LANTHANUM AND PRASEODYMIUM COMPLEXES WITH AT LEAST TWO POLYAMINOPOLYACETIC ACID SEQUESTERING AGENTS, CADMIUM CATION AND IODATE ANION, AND SEPARATING THE THUS FORMED PECIPITATE OF LANTHANUM IODATE.
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) | 1969-09-26 | 1970-03-28 | 1970-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-09-26 | 1974-03-28 | 1974-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-09-26 | 1978-03-28 | 1978-09-27 | $7700.00 | Window Closed / Lapsed |