US2778722A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Defluorination of phosphate rock
Assignee: SMITH DOUGLASS CO Inc
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Filing: 1954-01-19
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Granted: 1957-01-22
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Expires: 1974-01-19
Abstract
No abstract record available.
Inventors
- 👤 Clinton A Hollingsworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:07
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
130 words
THE METHOD OF DEFLUORINATING BY CALCINATION PHOSPHATE ROCK CONTAINING FLUORAPATITE, WHICH COMPRISES LOOSENING THE FLUORAPATITE LATTICE PRIOR TO CALCINATION BY TREATING THE PHOSPHATE ROCK WITH AN AQUEOUS SOLUTION BY HYDROCHLORIC ACID IN AMOUNT OF FROM 10 TO 30% BY WEIGHT OF HCI BASED ON THE COMBINED WEIGHT OF ROCK AND HCI, SUBJECTING THE TREATED ROCK TO A DRYING OPERATION AT A TEMPERATURE WITHIN THE RANGE OF 200 TO 800* F. IN THE COURSE OF WHICH MORE THAN HALF OF THE HYDROCHLORIC ACID ADMIXED WITH THE ROCK IS VOLATILIZED, AND CALCINING THE DRIED ROCK WITHOUT SUBSTANTIAL FUSION AT A TEMPERATURE OF AT LEAST 2400* F. IN THE PRESENCE OF WATER VAPOR AND THEREBY PRODUCING A TRICALCIUM PHOSPHATE PRODUCT CONTAINING LEAS THAN ONE PART OF FLUORINE FOR EACH 100 PARTS OF PHOSPHORUS.
Claim 2
Independent Claim
130 words
THE METHOD OF DEFLUORINATING BY CALCINATION PHOSPHATE ROCK CONTAINING FLUORAPATITE, WHICH COMPRISES LOOSENING THE FLUORAPATITE LATTICE PRIOR TO CALCINATION BY TREATING THE PHOSPHATE ROCK WITH AN AQUEOUS SOLUTION BY HYDROCHLORIC ACID IN AMOUNT OF FROM 10 TO 30% BY WEIGHT OF HCI BASED ON THE COMBINED WEIGHT OF ROCK AND HCI, SUBJECTING THE TREATED ROCK TO A DRYING OPERATION AT A TEMPERATURE WITHIN THE RANGE OF 200 TO 800* F. IN THE COURSE OF WHICH MORE THAN HALF OF THE HYDROCHLORIC ACID ADMIXED WITH THE ROCK IS VOLATILIZED, AND CALCINING THE DRIED ROCK WITHOUT SUBSTANTIAL FUSION AT A TEMPERATURE OF AT LEAST 2400* F. IN THE PRESENCE OF WATER VAPOR AND THEREBY PRODUCING A TRICALCIUM PHOSPHATE PRODUCT CONTAINING LEAS THAN ONE PART OF FLUORINE FOR EACH 100 PARTS OF PHOSPHORUS.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-01-22 | 1960-07-23 | 1961-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-01-22 | 1964-07-23 | 1965-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-01-22 | 1968-07-23 | 1969-01-22 | $7700.00 | Window Closed / Lapsed |