US3558440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of separating the rare earths by fractional co-distillation of their volatile chelate derivatives
Assignee: United States Department of the Air Force
•
Filing: 1968-06-04
•
Granted: 1971-01-26
•
Expires: 1988-06-04
Abstract
Abstract A METHOD OF SEPARATING BY FRACTIONAL DISTILLATION TWO OR MORE NON-VOLATILE COMPOUNDS OF RARE EARTHS COMPRISING THE STEPS OF CONVERTING THE COMPOUNDS OF THE RARE EARTHS TO THEIR CORRESPONDING VOLATILIZABLE CHELATE, DISTILLING A MIXTURE OF THE CHELATES AND A CO-DISTILLING AGENT TO OBTAIN ENRICHED FRACTIONS OF SAID CHELATES IN SAID AGENT, COLLECTING SAID ENRICHED FRACTIONS, ACIDIFYING EACH OF SAID FRACTIONS TO FORM (A) A WATER-RARE EARTH SALT PHASE AND (B) A CO-DISTILLING AGENT AND LIGAND PHASE, AND COLLECTING THE RARE EARTH SALT BY STRIPPING THE RARE EARTH SALT OF WATER.
Inventors
- 👤 Charles W Harris
- 👤 Robert E Sievers
- 👤 Kent J Eisentraut
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:30
CPC Classifications
C; C01; C01F; C01F17/00; C01F17/10; C01F17/20
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |