Patent US2693409A successfully refreshed from Google Patents.
US2693409A
Expired / Lapsed
US
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Treatment of iron ore
Assignee: Battelle Memorial Institute Inc
•
Filing: 1949-11-09
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Granted: 1954-11-02
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Expires: 1969-11-09
Abstract
No abstract record available.
Inventors
- 👤 Jr Frank M Stephens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:19
CPC Classifications
C; C22; C22B; C22B1/00; C22B1/02; C21; C21B; C21B13/00; C22B1/14; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/134
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
45 words
AN EXOTHERMIC PROCESS FOR OBTAINING IRON VALUES FROM IRON ORE INCLUDING THE STEPS OF PREHEATING THE ORE TO A TEMPERATURE OF AT LEAST 660* F., REDUCING THE PREHEATED ORE TO MAGNETIC, OXIDIZING SUFFICIENT OF SAID MAGNETITE TO MAGNETIC HEMATITE AT A TEMPERATURE OF FROM 390*
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-11-01 | 1958-05-03 | 1958-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-11-01 | 1962-05-03 | 1962-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-11-01 | 1966-05-03 | 1966-11-02 | $7700.00 | Window Closed / Lapsed |