US3755531A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for refining alumina
Assignee: Kao Corp
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Filing: 1971-08-19
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Granted: 1973-08-28
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Expires: 1991-08-19
Abstract
Abstract A CRUDE ALKALI ALUMINATE SOLUTION OBTAINED BY EXTRACTING ALUMINUM FROM ALUMINUM-CONTAINING ORES WITH CAUSTIC ALKALI SOLUTION IS ADDED WITH AN EMULSION OF A POLYACRYLIC ACID ESTER HOMOPOLYMER OR COPOLYMER TO PRECIPITATE RED MUD IN THE SOLUTION BY FLOCCULATON AND TO GIVE ALKALI ALUMINATE SOLUTION OF GOOD CLARITY.
Inventors
- 👤 M Tsukawaki
- 👤 Y Inamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:11
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/46; C01F7/47; C01F7/04; C01F7/06; C01F7/0646; C01F7/0653
Claims Analysis
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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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |