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US3843767A
Expired / Lapsed
US
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Process for treating fluophosphate ores
Assignee: EIDP Inc
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Filing: 1972-03-27
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Granted: 1974-10-22
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Expires: 1992-03-27
Abstract
Abstract The calcium, fluorine and phosphate values of calcium fluophosphate ores can be recovered by reacting the ores with phosphoric acid. The process is conducted by dissolving the ore in phosphoric acid solutions containing less F, Ca and SO4 impurities than found in conventional wet process phosphoric acid. The reaction is conducted at temperatures and for periods of time sufficient to dissolve at least 75 percent of the fluorine and phosphate values of the ore, but insufficient to react the fluorides with the silica impurities present in the ore. The impurities are separated by filtration or centrifugation and the desired values are recovered.
Inventors
- 👤 C Faust
- 👤 P Yates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:53
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/455; C01B25/18; C01B25/22; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/915
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
155 words
IN THE PROCESS FOR RECOVERING THE CALCIUM, FLUORINE, AND PHOSPHATE VALUES OF CALCIUM FLUORPHOSPHATE ORES BY ACID ATTACK FOLLOWED BY SEPARATION OF THE IMPURITIES AND RECOVERY OF THE DESIRED FLUORINE, PHOSPHATE AND CALCIUM VALUES, THE IMPROVEMENT COMPRISING DISSOLVING NO MORE THAN ABOUT 45 PARTS BY WEIGHT OF SAID ORE PER 100 PARTS BY WEIGHT ACID, BASED ON P205, IN 10 TO 60 PERCENT BY WEIGHT AQUEOUS PHOSPHORIC ACID, BASED ON P2O5 THE PHOSPHORIC ACID CONTAINING NO MORE THAT 0.3 PERCENT BY WEIGHT FLUORINE AND NO MORE THAN 30 PERCENT OF THE EQUILIBRIUM SOLUBILITY OF CASO4 AT THE ACID STRENGTH EMPLOYED, AT A TEMPERATURE OF FROM 50* TO 120*C FOR A TIME VARYING FROM 3 HOURS AT 50*C AND 5 MINUTES AT 120* C., SAID TIME BEING SUFFICIENT TO DISSOLVE ABOUT 75 PERCENT OF THE FLUORINE AND PHOSPHATE VALUES BUT INSUFFICIENT TO REACT ANY APPRECIABLE AMOUNT OF THE FLUORINE LIBERATED WITH THE SILICA IN SAID ORE.
Claim 2
Dependent Claim
155 words
IN THE PROCESS FOR RECOVERING THE CALCIUM, FLUORINE, AND PHOSPHATE VALUES OF CALCIUM FLUORPHOSPHATE ORES BY ACID ATTACK FOLLOWED BY SEPARATION OF THE IMPURITIES AND RECOVERY OF THE DESIRED FLUORINE, PHOSPHATE AND CALCIUM VALUES, THE IMPROVEMENT COMPRISING DISSOLVING NO MORE THAN ABOUT 45 PARTS BY WEIGHT OF SAID ORE PER 100 PARTS BY WEIGHT ACID, BASED ON P205, IN 10 TO 60 PERCENT BY WEIGHT AQUEOUS PHOSPHORIC ACID, BASED ON P2O5 THE PHOSPHORIC ACID CONTAINING NO MORE THAT 0.3 PERCENT BY WEIGHT FLUORINE AND NO MORE THAN 30 PERCENT OF THE EQUILIBRIUM SOLUBILITY OF CASO4 AT THE ACID STRENGTH EMPLOYED, AT A TEMPERATURE OF FROM 50* TO 120*C FOR A TIME VARYING FROM 3 HOURS AT 50*C AND 5 MINUTES AT 120* C., SAID TIME BEING SUFFICIENT TO DISSOLVE ABOUT 75 PERCENT OF THE FLUORINE AND PHOSPHATE VALUES BUT INSUFFICIENT TO REACT ANY APPRECIABLE AMOUNT OF THE FLUORINE LIBERATED WITH THE SILICA IN SAID ORE.
Claim 3
Dependent Claim
33 words
The process of claim 1 wherein the acid attack is for 5 minutes to 3 hours at 60* to 110* C. and the acid employed has a concentration of 10 to 50 percent.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |