US2807521A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phosphoric acid manufacture
Assignee: Chemical Construction Corp
•
Filing: 1953-11-09
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Granted: 1957-09-24
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Expires: 1973-11-09
Abstract
No abstract record available.
Inventors
- 👤 Wendell B Lambe
- 👤 Alfred R Smith
- 👤 Otani Herbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:39
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/22; C01B25/222; C01B25/223; C01B25/225
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
183 words
A METHOD FOR THE PRODUCTION OF PHOSPHORIC ACID WHICH COMPRISES MIXING WITH CONCENTRATED SULFURIC ACID A QUANTITY OF HOT DILUTE AQUEOUS PHOSPHORIC ACID SUCH AS TO PROVIDE BOTH THE AMOUNT OF WATER NECESSARY TO DILUTE THE MIXTURE TO A 25-40% SULFURIC ACID CONCENTRATION AND THE ADDITIONAL AMOUNT OF WATER WHICH WHEN CONVERTED INTO VAPOR WILL REMOVE THE HEAT OF DILUTION AS LATENT HEAT OF VAPORIZATION, COOLING THE MIXTURE TO DIGESTION TEMPERATURES AT WHICH A STABLE CALCIUM SULFATE DIHYDRATE WILL FORM IN THE SUBSEQUENT DIGESTION PROCESS BY SUBJECTING IT TO VACCUM EVAPORATION, FORMING A HOT CONDENSATE OF THE WATER REMOVED BY THE VACUUM EVAPORATION, DIGESTING GROUND PHOSPHATE ROCK BY MIXING IT WITH SAID COOLED DIGESTION ACID MIXTURE AND WITH RECYCLED PRODUCT PHOSPHORIC ACID AT SAID DIGESTION TEMPERATURES AND THEREBY FORMING A FILTERABLE SLURRY OF CALCIUM SULFATE DIHYDRATE IN AQUEOUS PHOSPHORIC ACID, FILTERING THE SLURRY AND WASHING THE FILTER CAKE WITH SAID HOT CONDENSATE TO REMOVE A MAJOR PORTION OF THE PHOSPHORIC ACID FROM SAID CAKE, AND RETURNING THE RESULTING HOT, DILUTE, AQUEOUD PHOSPHORIC ACID CONTAINING WASH WATER FOR ADMIXTURE WITH SAID CONCENTRATED SULFURIC ACID.
Claim 2
Independent Claim
183 words
A METHOD FOR THE PRODUCTION OF PHOSPHORIC ACID WHICH COMPRISES MIXING WITH CONCENTRATED SULFURIC ACID A QUANTITY OF HOT DILUTE AQUEOUS PHOSPHORIC ACID SUCH AS TO PROVIDE BOTH THE AMOUNT OF WATER NECESSARY TO DILUTE THE MIXTURE TO A 25-40% SULFURIC ACID CONCENTRATION AND THE ADDITIONAL AMOUNT OF WATER WHICH WHEN CONVERTED INTO VAPOR WILL REMOVE THE HEAT OF DILUTION AS LATENT HEAT OF VAPORIZATION, COOLING THE MIXTURE TO DIGESTION TEMPERATURES AT WHICH A STABLE CALCIUM SULFATE DIHYDRATE WILL FORM IN THE SUBSEQUENT DIGESTION PROCESS BY SUBJECTING IT TO VACCUM EVAPORATION, FORMING A HOT CONDENSATE OF THE WATER REMOVED BY THE VACUUM EVAPORATION, DIGESTING GROUND PHOSPHATE ROCK BY MIXING IT WITH SAID COOLED DIGESTION ACID MIXTURE AND WITH RECYCLED PRODUCT PHOSPHORIC ACID AT SAID DIGESTION TEMPERATURES AND THEREBY FORMING A FILTERABLE SLURRY OF CALCIUM SULFATE DIHYDRATE IN AQUEOUS PHOSPHORIC ACID, FILTERING THE SLURRY AND WASHING THE FILTER CAKE WITH SAID HOT CONDENSATE TO REMOVE A MAJOR PORTION OF THE PHOSPHORIC ACID FROM SAID CAKE, AND RETURNING THE RESULTING HOT, DILUTE, AQUEOUD PHOSPHORIC ACID CONTAINING WASH WATER FOR ADMIXTURE WITH SAID CONCENTRATED SULFURIC ACID.
References Cited (Backward Citations)
US1003681A
Cited
US1836672A
Cited
US1851179A
Cited
US1940689A
Cited
US2032457A
Cited
US2065848A
Cited
US2233956A
Cited
US2699985A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-09-23 | 1961-03-25 | 1961-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-09-23 | 1965-03-25 | 1965-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-09-23 | 1969-03-25 | 1969-09-24 | $7700.00 | Window Closed / Lapsed |