US2960397A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of calcium metal from contaminants
Assignee: Dow Chemical Co
•
Filing: 1958-09-03
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Granted: 1960-11-15
•
Expires: 1978-09-03
Abstract
No abstract record available.
Inventors
- 👤 George B Cobel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:39
CPC Classifications
C; C22; C22B; C22B26/00; C22B26/20
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
115 words
THE METHOD OF SEPARATING CALCIUM METAL FROM A MIXTURE OF CALCIUM METAL AND OCCLUDED AND ADHERING SOLID CONTAMINANTS HAVING A LOWER MELTING POINT THAN CALCUIM METAL CONSISTING OF SUBJECTING A COLUMN OF THE MIXTURE TO A TEMPERATURE GRADIENT DECREASING FROM THE TOP OF THE COLUMN DOWNWARDLY, THE TEMPERATURE AT THE UPPER PART OF SAID COLUMN BEING BETWEEN THE MELTING POINT AND BOILING POINT OF CALCIUM METAL AND THE TEMPERATURE OF THE LOWER PORTION OF SAID COLUMN BEING BETWEEN THE MELTING POINT OF THE CONTAMINANTS AND THE MELTING POINT OF CALCIUM METAL WHEREBY THE CALCIUM METAL RISES FORMING A MOLTEN-LAYER THEREOF IN THE UPPER PART OF THE COLUMN, AND THEREAFTER REMOVING THE CALCIUM LAYER THUS FORMED.
References Cited (Backward Citations)
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Cited
GB594152A
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US2572489A
Cited
US2739046A
Cited
US2739045A
Cited
US2813017A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-11-15 | 1964-05-16 | 1964-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-11-15 | 1968-05-16 | 1968-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-11-15 | 1972-05-16 | 1972-11-15 | $7700.00 | Window Closed / Lapsed |