US3803293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of phosphoric acid from unground phosphate rock
Assignee: Wyeth Holdings LLC
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Filing: 1972-05-26
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Granted: 1974-04-09
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Expires: 1992-05-26
Abstract
Abstract A NOVEL MULTIPLE STEP PROCESS FOR THE MANUFACTURE OF WET PROCESS PHOSPHORIC ACID FROM UNGROUND PHOSPHATE ROCK HAVING A MOISTURE CONTENT BETWEEN ABOUT 3% AND 15% BY WEIGTH AND A SURFACE AREA BETWEEN ABOUT 5 AND 105 SQ. CM./GRAM.
Inventors
- 👤 D Randolph
- 👤 R Bristow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:31
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/22
Claims Analysis
Total Claims: 0
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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) | 1977-04-08 | 1977-10-08 | 1978-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-08 | 1981-10-08 | 1982-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-08 | 1985-10-08 | 1986-04-09 | $7700.00 | Window Closed / Lapsed |