Patent US3687639A successfully refreshed from Google Patents.
US3687639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of finely divided potassium sulfate crystals
Assignee: IMC Fertilizer Inc
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Filing: 1970-05-25
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Granted: 1972-08-29
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Expires: 1990-05-25
Abstract
Abstract A PROCESS OF PRODUCING FINELY DIVIDED POTASSIUM SULFATE CRYSTALS SUITABLE FOR USE IN SLURRY FERTILIZERS FROM AN AQUEOUS SOLUTION CONTAINING POTASSIUM SULFATE WHICH COMPRISES DISSOLVING POTASSIUM CHLORIDE IN THE POTASSIUM SULFATE SOLUTION TO CAUSE THE POTASSIUM SULFATE TO CRYSTALLIZE. UPON DISSOLUTION OF THE POTASSIUM CHLORIDE, CRYSTALS OF POTASSIUM SULFATE ARE PRECIPITATED THAT ARE SUFFICIENTLY FINE TO BE SUITABLE FOR USE IN SLURRY FERTILIZERS.
Inventors
- 👤 Jan R Barlow
- 👤 Herbert P Pursell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:39
CPC Classifications
C; C01; C01D; C01D5/00; C05; C05D; C05D1/00; C05D1/02
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) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |