US3375922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for beneficiating diatomaceous earth ores
Assignee: Grefco Inc
•
Filing: 1965-08-09
•
Granted: 1968-04-02
•
Expires: 1985-08-09
Abstract
No abstract record available.
Inventors
- 👤 Carl C Martin
- 👤 Don T Goodhue
- 👤 Dorothy M Rengel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:25
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1456111A
Cited
US1438588A
Cited
US1606281A
Cited
US2981630A
Cited
US3020231A
Cited
US2957818A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-04-02 | 1971-10-02 | 1972-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-04-02 | 1975-10-02 | 1976-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-04-02 | 1979-10-02 | 1980-04-02 | $7700.00 | Window Closed / Lapsed |