US2781256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the rapid removal of sulphur and silicon from pig iron
Assignee: United States Steel Corp
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Filing: 1953-11-23
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Granted: 1957-02-12
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Expires: 1973-11-23
Abstract
No abstract record available.
Inventors
- 👤 John H Richards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:15
CPC Classifications
C; C21; C21C; C21C1/00; C21C1/02
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
140 words
A METHOD OF SIMULTANEOUSLY REDUCING THE SULPHUR AND SILICON CONTENTS OF PIG IRON SUBSTANTIALLY SATURATED WITH CARBON AND CONTAINING MANGANESE IN A RATIO OF 1.2 TO 1 RELATIVE TO THE SILICON CONTENT, WHICH CONSISTS IN CHARGING MOLTEN IRON INTO A BASIC-LINED VESSEL, CONVERING THE IRON WITH A SUBSTANTIALLY NEUTRAL LIME-SILICA SLAG HAVING A MELTING RANGE BELOW 1250*C., SAID SLAG INCLUDING ALSO SULPHUR-ABSORBING INGREDIENT SELECTED FROM THE GROUP CONSISTING OF FERROUS OXIDE, MANGANESE OXIDE AND MIXTURES THEREOF IN AMOUNT BETWEEN 10-50% BY WEIGHT OF THE SLAG, SURFACE-BLOWING SAID SLAG WITH OXYGEN-CONTAINING GAS FOR A FEW MINUTES, UNTIL THE OXYGEN PARTIALLY OXIDIZES THE SILICON AND MANGANESE CONTENTS OF THE LIQUID IRON, AND TERMINATING THE BLOW BEFORE THE CARBON CONTENT IS OXIDIZED TO A SUBSTANTIAL EXTENT, THEREBY CAUSING A PORTION OF THE SILICON AND SULPHUR OF THE IRON TO COMBINE WITH THE SLAG.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-02-12 | 1960-08-13 | 1961-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-02-12 | 1964-08-13 | 1965-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-02-12 | 1968-08-13 | 1969-02-12 | $7700.00 | Window Closed / Lapsed |