US2839377A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Edfluorination of phosphate rock
Assignee: SMITH DOUGLASS CO Inc
•
Filing: 1951-02-28
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Granted: 1958-06-17
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Expires: 1971-02-28
Abstract
No abstract record available.
Inventors
- 👤 Clinton A Hollingsworth
- 👤 John C Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:32
CPC Classifications
C; C05; C05B; C05B13/00; C05B13/02; Y; Y10; Y10S; Y10S71/00; Y10S71/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
98 words
THE METHOD OF DEFLUORINATING PHOSPHATE ROCK WHICH COMPRISES SUBJECTING THE ROCK WITH A SILICA CONTENT NOT EXCEEDING 6% TO CALCINATION AT A TEMPERATURE OF AT LEAST 2600*F. WITHOUT SUBSTANTIAL FUSION IN THE PRESENCE OF WATER VAPOR AND A REAGENT MIXTURE CONSISTING ESSENTIALLY OF THE REACTION PRODUCT OF SODIUM CARBONATE AND PHOSPHORIC ACID, THE MOL RATIO OF THE NA2O TO P2O5 CONTENT OF THE REACTION PRODUCT BEING BETWEEN 1.6 AND 2.8, AND THE CAO, NA2O, P2O5 AND SIO2 CONTENT OF THE COMBINED PHOSPHATE ROCK AND REAGENT MIXTURE BEING SUCH THAT THE MOL RATIO OF THESE CONSTITUENTS IN THE FORMULA
Claim 2
Independent Claim
98 words
THE METHOD OF DEFLUORINATING PHOSPHATE ROCK WHICH COMPRISES SUBJECTING THE ROCK WITH A SILICA CONTENT NOT EXCEEDING 6% TO CALCINATION AT A TEMPERATURE OF AT LEAST 2600*F. WITHOUT SUBSTANTIAL FUSION IN THE PRESENCE OF WATER VAPOR AND A REAGENT MIXTURE CONSISTING ESSENTIALLY OF THE REACTION PRODUCT OF SODIUM CARBONATE AND PHOSPHORIC ACID, THE MOL RATIO OF THE NA2O TO P2O5 CONTENT OF THE REACTION PRODUCT BEING BETWEEN 1.6 AND 2.8, AND THE CAO, NA2O, P2O5 AND SIO2 CONTENT OF THE COMBINED PHOSPHATE ROCK AND REAGENT MIXTURE BEING SUCH THAT THE MOL RATIO OF THESE CONSTITUENTS IN THE FORMULA
References Cited (Backward Citations)
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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) | 1961-06-16 | 1961-12-16 | 1962-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-16 | 1965-12-16 | 1966-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-16 | 1969-12-16 | 1970-06-17 | $7700.00 | Window Closed / Lapsed |