Patent US3909475A successfully refreshed from Google Patents.
Patent US2968528A successfully refreshed from Google Patents.
US2968528A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing clarified phosphoric acid
Assignee: International Minerals and Chemical Corp
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Filing: 1957-07-01
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Granted: 1961-01-17
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Expires: 1977-07-01
Abstract
No abstract record available.
Inventors
- 👤 Raymond E Tuttle
- 👤 William W Harwood
- 👤 Donald J Smalter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:08
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/234; C01B25/235; B; B60; B60S; B60S1/00; B60S1/02; B60S1/04; B60S1/32; B60S1/38
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
169 words
THE METHOD OF CLARIFYING CONCENTRATED ACIDIC PHOSPHORUS-BEARING SOLUTION SELECTED FROM THE GROUP CONSISTING OF WET PROCESS PHOSPHORIC ACID AND SOLUTIONS OF MIXTURES OF MONOCALCIUM PHOSPHATE AND WET PROCESS PHOSPHORIC ACID PREDOMINATED BY PHOSPHORIC ACID WHICH COMPRISES MIXING INTO SAID ACIDIC SOLUTION SUCCESSIVELY WITH AGITATION, FROM ABOUT 0.5% TO ABOUT 2.0% BY WEIGHT OF AN OXIDIZING AGENT SELECTED FROM THE GROUP CONSISTING OF NITRIC ACID, POTASSIUM PERMANGANATE, POTASSIUM DICHROMATE, HYPOCHLOROUS ACID, AND MIXTURES THEREOF, AGITATING THE MIXTURE FOR A PERIOD OF FROM ABOUT 3 MINUTES TO ABOUT 10 MINUTES, SUBSEQUENTLY ADDING FROM ABOUT 0.08 POUND TO ABOUT 0.3 POUND PER TON OF SAID ACIDIC SOLUTION OF A FLOCCULATING AGENT STABLE IN STRONG ACID SOLUTION SELECTED FROM THE GROUP CONSISTING OF WATER-SOLUBLE HIGH MOLECULAR WEIGHT SYNTHETIC POLYACRYLAMIDE RESIN, WATER-SOLUBLE HIGH MOLECULAR WEIGHT HYDROLYZED SYNTHETIC POLYACRYLONITRILE RESIN, AND THE POTASSIUM AND SODIUM SALTS THEREOF, AND MIXTURES THEREOF, HOLDING THE MIXTURE AT A TEMPERATURE OF BETWEEN ABOUT 180*F. AND ABOUT 200*F., AND SEPARATELY RECOVERING A CLEAR ACIDIC FRACTION AND A SOLIDS CARRYING FRACTION.
Claim 2
Independent Claim
169 words
THE METHOD OF CLARIFYING CONCENTRATED ACIDIC PHOSPHORUS-BEARING SOLUTION SELECTED FROM THE GROUP CONSISTING OF WET PROCESS PHOSPHORIC ACID AND SOLUTIONS OF MIXTURES OF MONOCALCIUM PHOSPHATE AND WET PROCESS PHOSPHORIC ACID PREDOMINATED BY PHOSPHORIC ACID WHICH COMPRISES MIXING INTO SAID ACIDIC SOLUTION SUCCESSIVELY WITH AGITATION, FROM ABOUT 0.5% TO ABOUT 2.0% BY WEIGHT OF AN OXIDIZING AGENT SELECTED FROM THE GROUP CONSISTING OF NITRIC ACID, POTASSIUM PERMANGANATE, POTASSIUM DICHROMATE, HYPOCHLOROUS ACID, AND MIXTURES THEREOF, AGITATING THE MIXTURE FOR A PERIOD OF FROM ABOUT 3 MINUTES TO ABOUT 10 MINUTES, SUBSEQUENTLY ADDING FROM ABOUT 0.08 POUND TO ABOUT 0.3 POUND PER TON OF SAID ACIDIC SOLUTION OF A FLOCCULATING AGENT STABLE IN STRONG ACID SOLUTION SELECTED FROM THE GROUP CONSISTING OF WATER-SOLUBLE HIGH MOLECULAR WEIGHT SYNTHETIC POLYACRYLAMIDE RESIN, WATER-SOLUBLE HIGH MOLECULAR WEIGHT HYDROLYZED SYNTHETIC POLYACRYLONITRILE RESIN, AND THE POTASSIUM AND SODIUM SALTS THEREOF, AND MIXTURES THEREOF, HOLDING THE MIXTURE AT A TEMPERATURE OF BETWEEN ABOUT 180*F. AND ABOUT 200*F., AND SEPARATELY RECOVERING A CLEAR ACIDIC FRACTION AND A SOLIDS CARRYING FRACTION.
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) | 1964-01-17 | 1964-07-18 | 1965-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-01-17 | 1968-07-18 | 1969-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-01-17 | 1972-07-18 | 1973-01-17 | $7700.00 | Window Closed / Lapsed |