Patent US3813233A successfully refreshed from Google Patents.
US3813233A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of suspension fertilizers from wet-process orthophosphoric acids
Assignee: Tennessee Valley Authority
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Filing: 1973-04-23
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Granted: 1974-05-28
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Expires: 1993-04-23
Abstract
Abstract A PROCESS FOR PREPARING CONCENTRATED, HIGH-GRADE N-P2O5(E.G. 12-40-0) AND MIXED N-P2O5-K2O (E.G. 14-14-14) SUSPENSION FERTILLIZERS WITH EXCEPTIONALLY SATISFACTORY LONG-TERM STORAGE PROPERTIES FROM MERCHANT GRADE (50-54 PERCENT P2O5) WET-PROCESS PHOSPHORIC ACID OR OTHER IMPURE PHOSPHORIC ACIDS. THE PROCESS INVOLVES AMMONITATION OF THE ACID INN TWO OR MORE STEPS TO REDUCE PRECIPITATION OF AMORPHOUS MATEIRALS DERIVED FROM THE IMPURITIES WHICH HAVE GEL-LIKE PROPERTIES THAT DESTROY FLUDITY OF THE FERTILLIZER PRODUCTS. OTHEER FACTORS IMPORTANT TO SUCCESSFUL OPERATION OF THE PROCESS ARE PH, REACTION TEMPERATURE AND RETENTION TIME IN EACH STEP OR STAGE.
Inventors
- 👤 L Kendrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:51
CPC Classifications
C; C05; C05B; C05B7/00
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) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |