Patent US5325410A successfully refreshed from Google Patents.
Patent US2175472A successfully refreshed from Google Patents.
Patent US4809275A successfully refreshed from Google Patents.
Patent US3423718A successfully refreshed from Google Patents.
Patent FR1115946A successfully refreshed from Google Patents.
Patent US3375922A successfully refreshed from Google Patents.
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
2026-11-02 15:14
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/14
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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 |