Patent US2905535A successfully refreshed from Google Patents.
US2905535A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phosphoric acid concentration
Assignee: Chemical Construction Corp
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Filing: 1955-12-19
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Granted: 1959-09-22
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Expires: 1975-12-19
Abstract
No abstract record available.
Inventors
- 👤 Atkin Sydney
- 👤 Sidney S Prince
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:09
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/08; C01B33/10; C01B33/103; C01B25/00; C01B25/16; C01B25/18; C01B25/234; C01B25/2343; Y; Y10; Y10S; Y10S159/00; Y10S159/19
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
177 words
A METHOD OF CONCENTRATING A DILUTE IMPURE AQUEOUS PHOSPHORIC ACID CONTAINING COMPOUNDS OF SILICON AND FLUORINE AS IMPURITIES TO A PRODUCT PHOSPHORIC ACID WHILE SIMULTANEOUSLY ELIMINATING SAID IMPURITIES WHICH COMPRISES ESTABLISHING IN A DRUM-TYPE CONCENTRATOR A BODY OF DILUTE PHOSPHORIC ACID HAVING A 20-35% P2O5 CONTENT, PASSING A STREAM OF HOT GAS THROUGH THE DILUTE IMPURE PHOSPHORIC ACID IN A CONCENTRATING STEP WHEREBY HOT GAS INTRODUCED INTO THE BODY OF SAID DILUTE PHOSPHORIC ACID PRODUCES A PRODUCT PHOSPHORIC ACID HAVING A P2O5 CONTENT OF AT LEAST 5/% AND A STACK GAS CONTAINING SAID IMPURITIES ALONG WITH VOLATILIZED PHOSPHORIC ACID AND WATER VAPOR, SAID STACK GAS LEAVING THE PHOSPHORIC ACID BEING CONCENTRATED AT A TEMPERATURE OF BETWEEN 225* F. AND 275* F., THEREAFTER SCRUBBING SAID STACK GAS WITH AN AQUEOUS PHOSPHORIC ACID HAVING A P2O5 CONTENT OF AT LEAST 20% AND NOT OVER 35% THEREBY REMOVING SAID VOLATILIZED PHOSPHORIC ACID FROM SAID STACK GAS WHILE DISSOLVING LIMITED QUANTITIES ONLY OF SILICON- AND FLUORINE-CONTAINING COMPOUNDS THEREIN, AND RECYCLING A PORTION OF THE RESULTING SCRUBBING LIQUID TO THE CONCENTRATING STEP.
Claim 2
Independent Claim
177 words
A METHOD OF CONCENTRATING A DILUTE IMPURE AQUEOUS PHOSPHORIC ACID CONTAINING COMPOUNDS OF SILICON AND FLUORINE AS IMPURITIES TO A PRODUCT PHOSPHORIC ACID WHILE SIMULTANEOUSLY ELIMINATING SAID IMPURITIES WHICH COMPRISES ESTABLISHING IN A DRUM-TYPE CONCENTRATOR A BODY OF DILUTE PHOSPHORIC ACID HAVING A 20-35% P2O5 CONTENT, PASSING A STREAM OF HOT GAS THROUGH THE DILUTE IMPURE PHOSPHORIC ACID IN A CONCENTRATING STEP WHEREBY HOT GAS INTRODUCED INTO THE BODY OF SAID DILUTE PHOSPHORIC ACID PRODUCES A PRODUCT PHOSPHORIC ACID HAVING A P2O5 CONTENT OF AT LEAST 5/% AND A STACK GAS CONTAINING SAID IMPURITIES ALONG WITH VOLATILIZED PHOSPHORIC ACID AND WATER VAPOR, SAID STACK GAS LEAVING THE PHOSPHORIC ACID BEING CONCENTRATED AT A TEMPERATURE OF BETWEEN 225* F. AND 275* F., THEREAFTER SCRUBBING SAID STACK GAS WITH AN AQUEOUS PHOSPHORIC ACID HAVING A P2O5 CONTENT OF AT LEAST 20% AND NOT OVER 35% THEREBY REMOVING SAID VOLATILIZED PHOSPHORIC ACID FROM SAID STACK GAS WHILE DISSOLVING LIMITED QUANTITIES ONLY OF SILICON- AND FLUORINE-CONTAINING COMPOUNDS THEREIN, AND RECYCLING A PORTION OF THE RESULTING SCRUBBING LIQUID TO THE CONCENTRATING STEP.
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) | 1962-09-21 | 1963-03-23 | 1963-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-09-21 | 1967-03-23 | 1967-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-09-21 | 1971-03-23 | 1971-09-22 | $7700.00 | Window Closed / Lapsed |