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Patent US3707357A successfully refreshed from Google Patents.
US3707357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wet-process phosphoric acid extraction including separating solvent from extract by freezing solvent
Assignee: United States Steel Corp
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Filing: 1971-03-23
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Granted: 1972-12-26
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Expires: 1991-03-23
Abstract
Abstract PHOSPHORIC ACID IS SELECTIVELY EXTRACTED FROM IMPURE WET-PROCESS PHOSPHORIC ACID AND THEN STRIPPED FROM THE SOLVENT EXTRACT BY CRYSTALLIZATION OF THE SOLVENT WITH OR WITHOUT THE ADDITION OF WATER.
Inventors
- 👤 Peter T Chiang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:31
CPC Classifications
B; B01; B01D; B01D11/00; B01D11/04; B01D11/0488; C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/234
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) | 1975-12-26 | 1976-06-26 | 1976-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-26 | 1980-06-26 | 1980-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-26 | 1984-06-26 | 1984-12-26 | $7700.00 | Window Closed / Lapsed |