US2995437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Defluorination of phosphate rock
Assignee: SMITH DOUGLASS CO Inc
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Filing: 1959-04-23
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Granted: 1961-08-08
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Expires: 1979-04-23
Abstract
No abstract record available.
Inventors
- 👤 Clinton A Hollingsworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:08
CPC Classifications
C; C05; C05B; C05B13/00; C05B13/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
119 words
IN THE METHOD OF DEFLUORINATING PHOSPHATE ROCK WHICH COMPRISES HEATING THE ROCK AT AN ELEVATED TEMPERATURE WITHOUT SUBSTANTIAL FUSION IN THE PRESENCE OF WATER VAPOR AND OF AN ADDED SODIUM COMPOUND OF THE GROUP CONSISTING OF SODIUM CARBONATE, SODIUM BICARBONATE, SODIUM HYDROXIDE, SODIUM PHOSPHATES AND SODIUM CHLORIDE AND AN ADDED ACID PHOSPHATE COMPOUND OF THE GROUP CONSISTING OF THE PHOSPHOROUS ACIDS AND THEIR ACID SODIUM SALTS, AND MAINTAINING THE CHARGE AT SAID ELEVATED TEMPERATURE FOR A SUFFICIENT TIME TO PRODUCE A DEFLUORINATED PHOSPHATE PRODUCT, THE IMPROVEMENT WHICH COMPRISES PROPORTIONING THE RELATIVE AMOUNTS OF PHOSPHATE ROCK, SILICA, ADDED SODIUM COMPOUNDS AND ADDED PHOSPHATE COMPOUNDS PRESENT IN THE CHARGE MIXTURE SO THAT THE WEIGHT RATIO OF THE ADDED SODIUM COMPOUND (CALCULATED
Claim 2
Dependent Claim
119 words
IN THE METHOD OF DEFLUORINATING PHOSPHATE ROCK WHICH COMPRISES HEATING THE ROCK AT AN ELEVATED TEMPERATURE WITHOUT SUBSTANTIAL FUSION IN THE PRESENCE OF WATER VAPOR AND OF AN ADDED SODIUM COMPOUND OF THE GROUP CONSISTING OF SODIUM CARBONATE, SODIUM BICARBONATE, SODIUM HYDROXIDE, SODIUM PHOSPHATES AND SODIUM CHLORIDE AND AN ADDED ACID PHOSPHATE COMPOUND OF THE GROUP CONSISTING OF THE PHOSPHOROUS ACIDS AND THEIR ACID SODIUM SALTS, AND MAINTAINING THE CHARGE AT SAID ELEVATED TEMPERATURE FOR A SUFFICIENT TIME TO PRODUCE A DEFLUORINATED PHOSPHATE PRODUCT, THE IMPROVEMENT WHICH COMPRISES PROPORTIONING THE RELATIVE AMOUNTS OF PHOSPHATE ROCK, SILICA, ADDED SODIUM COMPOUNDS AND ADDED PHOSPHATE COMPOUNDS PRESENT IN THE CHARGE MIXTURE SO THAT THE WEIGHT RATIO OF THE ADDED SODIUM COMPOUND (CALCULATED
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) | 1964-08-07 | 1965-02-06 | 1965-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-07 | 1969-02-06 | 1969-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-07 | 1973-02-06 | 1973-08-08 | $7700.00 | Window Closed / Lapsed |