US3692671A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rare earth ion removal from waste water
Assignee: Boeing North American Inc
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Filing: 1970-10-01
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Granted: 1972-09-19
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Expires: 1990-10-01
Abstract
Abstract A METHOD IS PROVIDED FOR CHEMICALLY REMOVING TRIVALENT RARE EARTH IONS FROM WASTE WATER BY TREATING THE TRIVALENT RARE EARTH ION-CONTAINING WATER WITH A CARBONATE SALT, SUCH AS AN ALKALI METAL CARBONATE, TO FORM AN INSOLUBLE RARE EARTH CARBONATE PRECIPITATE AND THEN SEPARATING THE PRECIPITATE FROM THE WATER. THE RARE EARTH IONS MAY BE REGENERATED IN THE FORM OF A SOLUBLE RARE EARTH SALT, FOR EXAMPLE, BY TREATING THE SEPARATED RARE EARTH CARBONATE PRECIPITATE WITH ACID, SUCH AS HYDROCHLORIC OR SULFURIC ACID.
Inventors
- 👤 Howard L Recht
- 👤 Masood Ghassemi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:58
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; C01; C01F; C01F17/00; C01F17/20; C01F17/247; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/917
Claims Analysis
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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) | 1975-09-19 | 1976-03-20 | 1976-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-19 | 1980-03-20 | 1980-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-19 | 1984-03-20 | 1984-09-19 | $7700.00 | Window Closed / Lapsed |