Patent US3138551A successfully refreshed from Google Patents.
US3138551A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filtering composition and process
Assignee: Kaiser Aluminum and Chemical Corp
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Filing: 1959-04-21
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Granted: 1964-06-23
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Expires: 1979-04-21
Abstract
No abstract record available.
Inventors
- 👤 Robert L Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:32
CPC Classifications
B; B01; B01D; B01D37/00; B01D37/02
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
67 words
A PROCESS OF FILTERING CAUSTIC ALUMINATE LIQUOR CONTAINING SUSPENDED RED MUD PARTICLES WHICH COMPRISES COATING A POROUS FILTER MEDIUM WITH A LAYER OF FILTER AIR COMPRISING IN ADMIXTURE THE ORTHORHOMBIC AND HEXAGONAL CRYSTALLINE FORMS OF CALCIUM CARBONATE AND SUBSEQUENTLY FILTERING FILTERING SAID LIQUOR THROUGH SAID LAYER OF FILTER AID AND SAID FILTER MEDIUM, SAID ORTHORHOMBIC CALCIUM CARBONATE BEING IN THE FORM OF NEEDLE-LIKE PARTICLES AND NEEDLE CLUSTERS.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-06-23 | 1967-12-23 | 1968-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-06-23 | 1971-12-23 | 1972-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-06-23 | 1975-12-23 | 1976-06-23 | $7700.00 | Window Closed / Lapsed |