US2981597A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of ammonium cryolite
Assignee: Tennessee Valley Authority
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Filing: 1958-10-13
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Granted: 1961-04-25
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Expires: 1978-10-13
Abstract
No abstract record available.
Inventors
- 👤 Tarbutton Grady
- 👤 Thad D Farr
- 👤 Thomas M Jones
- 👤 Jr Harry T Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:03
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/48; C01F7/50; C01F7/54; C01F7/78; C01F7/788
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
137 words
A PROCESS FOR THE MANUFACTURE OF AMMONIUM CRYOLITE OF SPECIFICATION GRADE WHICH COMPRISES PREPARING AN IMPURE SOLUTION OF AMMONIUM FLUORIDE CONTAINING FLUORINE AND PHOSHORUS COMPOUNDS IN SUCH PROPORTIONS THAT THE WEIGHT RATION F:P2O5 IS IN THE RANGE FROM 1:1 TO 400:1, CONTAINING AT LEAST ENOUGH AMMONIUM ION TO FORM (NH4)3ALF6 WITH ALL FLUORINE PRESENT AND CONTAINING NOT MORE SILICA AND IRON THAN REPRESENTED BY F:SIO2 AND F:FE2O3 WEIGHT RATIOS OF 15:1 AND 100:1, RESPECTIVELY, ADJUSTING THE PH OF THE SOLUTION IN DEPENDENT RELATIONSHIP TO THE WEIGHT RATION F:P2O5 SUCH THAT THE MINIMUM PH IS ABOUT 4.0 AT A WEIGHT RATIO F:P2O5 OF ABOUT 1:1, AND SIMULTANEOUSLY INCREASING IN PROPORTIONATE RELATIONSHIP SUBSTANTIALLY CORRESPONDING TO A PROPORTIONAL INCREASE IN THE WEIGHT RATIO F:P2O5 THE PH OF SAID SOLUTION UP TO A MAXIMUM OF ABOUT 7.0 AT A WEIGHT RATIO
Claim 2
Dependent Claim
137 words
A PROCESS FOR THE MANUFACTURE OF AMMONIUM CRYOLITE OF SPECIFICATION GRADE WHICH COMPRISES PREPARING AN IMPURE SOLUTION OF AMMONIUM FLUORIDE CONTAINING FLUORINE AND PHOSHORUS COMPOUNDS IN SUCH PROPORTIONS THAT THE WEIGHT RATION F:P2O5 IS IN THE RANGE FROM 1:1 TO 400:1, CONTAINING AT LEAST ENOUGH AMMONIUM ION TO FORM (NH4)3ALF6 WITH ALL FLUORINE PRESENT AND CONTAINING NOT MORE SILICA AND IRON THAN REPRESENTED BY F:SIO2 AND F:FE2O3 WEIGHT RATIOS OF 15:1 AND 100:1, RESPECTIVELY, ADJUSTING THE PH OF THE SOLUTION IN DEPENDENT RELATIONSHIP TO THE WEIGHT RATION F:P2O5 SUCH THAT THE MINIMUM PH IS ABOUT 4.0 AT A WEIGHT RATIO F:P2O5 OF ABOUT 1:1, AND SIMULTANEOUSLY INCREASING IN PROPORTIONATE RELATIONSHIP SUBSTANTIALLY CORRESPONDING TO A PROPORTIONAL INCREASE IN THE WEIGHT RATIO F:P2O5 THE PH OF SAID SOLUTION UP TO A MAXIMUM OF ABOUT 7.0 AT A WEIGHT RATIO
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-04-24 | 1964-10-24 | 1965-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-24 | 1968-10-24 | 1969-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-24 | 1972-10-24 | 1973-04-25 | $7700.00 | Window Closed / Lapsed |