Patent US2987376A successfully refreshed from Google Patents.
US2987376A
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Method for defluorination of phosphoric acid
Assignee: International Minerals and Chemical Corp
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Filing: 1956-12-27
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Granted: 1961-06-06
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Expires: 1976-12-27
Abstract
No abstract record available.
Inventors
- 👤 Gunter H Gloss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:31
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/234; C01B25/237; C01B25/2372; C01B25/2375
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
117 words
THE METHOD OF REMOVING FLUORINE FROM WET PROCESS PHOSPHORIC ACID CONTAINING FLUORINE IN UNDESIRABLE AMOUNTS WHICH COMPRISES HEATING SAID ACID AT A CONCENTRATION HAVING A BOILING POINT HIGHER THAN ABOUT 250* F. TO A BOILING TEMPERATURE IN THE PRESENCE OF IN EXCESS OF ABOUT 0.1% BY WEIGHT OF SILICA HAVING A SURFACE AREA IN EXCESS OF 25 SQUARE METERS PER GRAM, BOILINT THE RESULTANT ACID SLURRY WHEREBY WATER VAPOR AND SILICON TETRAFLUORIDE ARE VAPORIZED AND REMOVED WHILE CONTINUOUSLY ADDING WATER TO MAINTAIN A SUBSTANTIALLY CONSTANT BOILING COMPOSITION BOILING HIGHER THAN ABOUT 250*F., WITHDRAWING A PHOSPHORIC ACID-SILICA SLURRY FROM THE BOILING OPERATION HAVING A P/F WEIGHT RATIO IN EXCESS OF 100, AND REMOVING SILICA FROM THE DEFLUORINATED ACID.
Claim 2
Independent Claim
117 words
THE METHOD OF REMOVING FLUORINE FROM WET PROCESS PHOSPHORIC ACID CONTAINING FLUORINE IN UNDESIRABLE AMOUNTS WHICH COMPRISES HEATING SAID ACID AT A CONCENTRATION HAVING A BOILING POINT HIGHER THAN ABOUT 250* F. TO A BOILING TEMPERATURE IN THE PRESENCE OF IN EXCESS OF ABOUT 0.1% BY WEIGHT OF SILICA HAVING A SURFACE AREA IN EXCESS OF 25 SQUARE METERS PER GRAM, BOILINT THE RESULTANT ACID SLURRY WHEREBY WATER VAPOR AND SILICON TETRAFLUORIDE ARE VAPORIZED AND REMOVED WHILE CONTINUOUSLY ADDING WATER TO MAINTAIN A SUBSTANTIALLY CONSTANT BOILING COMPOSITION BOILING HIGHER THAN ABOUT 250*F., WITHDRAWING A PHOSPHORIC ACID-SILICA SLURRY FROM THE BOILING OPERATION HAVING A P/F WEIGHT RATIO IN EXCESS OF 100, AND REMOVING SILICA FROM THE DEFLUORINATED ACID.
References Cited (Backward Citations)
US1858203A
Cited
US2165100A
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US2132349A
Cited
US2354177A
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US2526776A
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US2726928A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-06-05 | 1964-12-05 | 1965-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-05 | 1968-12-05 | 1969-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-05 | 1972-12-05 | 1973-06-06 | $7700.00 | Window Closed / Lapsed |