Patent US3666513A successfully refreshed from Google Patents.
US3666513A
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US
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Treatment of minerals
Assignee: Imerys Minerals Ltd
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Filing: 1970-03-25
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Granted: 1972-05-30
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Expires: 1990-03-25
Abstract
Abstract A PROCESS FOR IMPROVING THE BRIGHTNESS OF PHYLLOSILICATE MINERALS CONTAINING FERRIC IOINS IN SOLID SOLUTION WITHIN THE CRYSTAL LATTICE OF THE MINERALS. THE PROCESS COMPRISES THE STEPS OF BLEACHING BY A REDUCING BLEACHING AGENT AN INTERCALATION COMPLEX OF A PHYLLOSILICATE MINERAL AND THEREAFTER DECOMPOSING THE INTERCALATION COMPLEX UNDER NON-OXIDISING CONDITIONS.
Inventors
- 👤 Peter James Malden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:43
CPC Classifications
C; C04; C04B; C04B33/00; C04B33/02; C04B33/04; C04B33/06; C04B33/30; C09; C09C; C09C1/00; C09C1/40; C09C1/42; C01; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/60
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) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |