Patent US3554536A successfully refreshed from Google Patents.
Patent US3567474A successfully refreshed from Google Patents.
US3567474A
Expired / Lapsed
US
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Treatment of clay
Assignee: Imerys Minerals Ltd
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Filing: 1968-08-06
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Granted: 1971-03-02
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Expires: 1988-08-06
Abstract
Abstract A MINERAL HAVING A LAYER LATTICE CRYSTAL STRUCTURE, FOR EXAMPLE A CLAY MINERAL, IS BLEACHED BY FIRST FORMING AN INTERCALATION COMPLEX WITH, FOR EXAMPLE, UREA AND THEREAFTER BLEACHING THE INTERCALATION COMPLEX WITH AN OXIDISING BLEACHING AGENT.
Inventors
- 👤 Peter James Malden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:32
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/36; C01B33/38; C01B33/42; C01B33/26; C01B33/40; C01B33/46; C04; C04B; C04B33/00; C04B33/02; C04B33/10
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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |