US3592590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluosilicic acid purification
Assignee: Freeport Mcmoran Resource Partners Ltd
•
Filing: 1969-06-18
•
Granted: 1971-07-13
•
Expires: 1989-06-18
Abstract
Abstract FLUOSILICIC ACID CONTAINING IMPURITIES SUCH AS PHOSPHORUS PENTOXIDE IS PURIFIED BY ADMIXING IT WITH SULFURIC ACID, HEATING THE MIXTURE TO EVOLVE HYDROGEN FLUORIDE AND SILICON TETRAFLUORIDE VAPORS, SWEEPING THE VAPOR SPACE ABOVE THE HEATED MIXTURE WITH A SUPERHEATED CONDENSIBLE GAS SUCH AS STEAM, AND ABSORBING THE SIF4 AND HF VAPORS IN WATER.
Inventors
- 👤 Warren A Knarr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:55
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/08; C01B33/10; C01B33/103
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |