Patent US2914474A successfully refreshed from Google Patents.
US2914474A
Expired / Lapsed
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Removal of fluorides from industrial waste waters
Assignee: Phillips Petroleum Co
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Filing: 1954-07-29
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Granted: 1959-11-24
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Expires: 1974-07-29
Abstract
No abstract record available.
Inventors
- 👤 John C Hillyer
- 👤 Joseph F Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:54
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/58; C02F1/583; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/915
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
81 words
A PROCESS FOR TREATING AN AQUEOUS SOLUTION HAVING A PH OF LESS THAN 3 CONTAINING COMBINED FLUORIDE, A SUBSTANTIAL PORTION OF WHICH IS IN THE FORM OF FLUOSILICIC ACID, WHICH COMPRISES RAISING THE PH OF SAMDE TO AT LEAST 5 BY ADDING CALCIUM CARBONATE THERETO AND ADDING SUFFICIENT CALCIUM SULFATE TO PROVIDE CALCIUM IONS IN EXCESS OF THE FLUORINE IN SAID SOLUTION SO AS TO PRECIPITATE FLUORINE AS CALCIUM FLUORINE AND REDUCE THE FLUORINE CONTENT TO A MAXIMUM OF 20 P.P.M.
Claim 2
Dependent Claim
81 words
A PROCESS FOR TREATING AN AQUEOUS SOLUTION HAVING A PH OF LESS THAN 3 CONTAINING COMBINED FLUORIDE, A SUBSTANTIAL PORTION OF WHICH IS IN THE FORM OF FLUOSILICIC ACID, WHICH COMPRISES RAISING THE PH OF SAMDE TO AT LEAST 5 BY ADDING CALCIUM CARBONATE THERETO AND ADDING SUFFICIENT CALCIUM SULFATE TO PROVIDE CALCIUM IONS IN EXCESS OF THE FLUORINE IN SAID SOLUTION SO AS TO PRECIPITATE FLUORINE AS CALCIUM FLUORINE AND REDUCE THE FLUORINE CONTENT TO A MAXIMUM OF 20 P.P.M.
References Cited (Backward Citations)
GB261708A
Cited
US2257111A
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US2126793A
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US2376897A
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US2371759A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-11-23 | 1963-05-25 | 1963-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-11-23 | 1967-05-25 | 1967-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-11-23 | 1971-05-25 | 1971-11-24 | $7700.00 | Window Closed / Lapsed |