US3716617A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing alumina
Assignee: Sumitomo Chemical Co Ltd
•
Filing: 1970-04-13
•
Granted: 1973-02-13
•
Expires: 1990-04-13
Abstract
Abstract IMPROVED PROCESS FOR PRODUCING ALUMINA ACCORDING TO THE BAYER PROCESS WHEREIN THE DIGESTION RESIDUE IS SEPARATED FROM THE SODIUM ALUMINATE SOLUTION, RESULTING FROM THE DIGESTION OF AN ALUMINA-CONTAINING ORE, BY USING A SYNTHETIC ORGANIC HIGH MOLECULAR WEIGHT FLOCCULANT AND CONDUCTING THE SEPARATION ONLY WHEN AT LEAST 5% BY WEIGHT OF REACTIVE SILICA REMAINS IN THE DIGESTION RESIDUE. WITH THIS PROCESS, SODA CONCENTRATIONS HIGHER THAN 70 G./L. MAY BE UTILIZED FOR DIGESTION.
Inventors
- 👤 T Oku
- 👤 A Suzuki
- 👤 N Tawara
- 👤 K Niwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:44
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/06; C01F7/0646
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) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |