US2535217A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of materials containing tungsten compounds
Assignee: WAH CHANG TRADING Corp
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Filing: 1948-08-24
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Granted: 1950-12-26
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Expires: 1968-08-24
Abstract
No abstract record available.
Inventors
- 👤 Li Kuo Ching
- 👤 Dice Carl Marion
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:54
CPC Classifications
C; C22; C22B; C22B34/00; C22B34/30; C22B34/36
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
74 words
THE PROCESS OF RECOVERING TUNGSTEN FROM TUNGSTEN OXIDE BEARING MATERIALS WHICH INCLUDES REDUCING SAID OXIDE WITH CARBON AT TEMPERATURES IN EXCESS OF 2500* FAHRENHEIT IN THE PRESENCE OF IRON-TIN ALLOY CONTAINING BETWEN ABOUT 5 TO 75 PER CENT BY WEIGHT OF TIN, THE TOTAL AMOUNT OF SUCH ALLOY BEING SUCH THAT IT COMPOSES AT LEAST ABOUT 10 PER CENT OF THE TOTAL WEIGHT OF SAID ALLOY AND THE TUNGSTEN CONTAINING PRODUCT OF SAID REDUCTION.
Claim 2
Dependent Claim
74 words
THE PROCESS OF RECOVERING TUNGSTEN FROM TUNGSTEN OXIDE BEARING MATERIALS WHICH INCLUDES REDUCING SAID OXIDE WITH CARBON AT TEMPERATURES IN EXCESS OF 2500* FAHRENHEIT IN THE PRESENCE OF IRON-TIN ALLOY CONTAINING BETWEN ABOUT 5 TO 75 PER CENT BY WEIGHT OF TIN, THE TOTAL AMOUNT OF SUCH ALLOY BEING SUCH THAT IT COMPOSES AT LEAST ABOUT 10 PER CENT OF THE TOTAL WEIGHT OF SAID ALLOY AND THE TUNGSTEN CONTAINING PRODUCT OF SAID REDUCTION.
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) | 1953-12-25 | 1954-06-26 | 1954-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-12-25 | 1958-06-26 | 1958-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-12-25 | 1962-06-26 | 1962-12-26 | $7700.00 | Window Closed / Lapsed |