US3595640A
Expired / Lapsed
US
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Process for producing dispersion strengthened iron powder
Assignee: W J DENNIS STONE
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Filing: 1968-10-17
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Granted: 1971-07-27
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Expires: 1988-10-17
Abstract
Abstract A FINELY DIVIDED NATURL HEMATITE ORE CONCENTRATE CONTAINING SILICA, ALUMINA AND OTHER ACID INSOLUBLE IMPURITIES IS PASSED THROUGH A HIGH INTENSITY WET MAGNETIC SEPARATOR TO REMOVE IMPURITIES OTHER THAN ALUMINA, AFTER WHICH THE PURIFIED, FINELY DIVIDED HEMATITE, IS REDUCED IN THE PRESENCE OF HYDROGEN AT A TEMPERATURE BELOW THE MELTING POINT OF IRON AND THE IRON POWDER OBTAINED WITH ALUMINA UNIFORMLY DISPERSED THEREIN IS COLLECTED.
Inventors
- 👤 W J Dennis Stone
- 👤 David Stewart Hay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:46
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0235; B; B22; B22F; B22F9/00; B22F9/16; B22F9/18; B22F9/20; C21; C21B; C21B13/00; C21B13/006; C21B13/14; C21B13/146; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/134; Y10; Y10S; Y10S75/00; Y10S75/956
Claims Analysis
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References Cited (Backward Citations)
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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) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |