US3826647A
Expired / Lapsed
US
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Method of obtaining low-phosphorus contents in medium-and high-carbon steels in a bottom-blown oxygen steelmaking furnace
Assignee: United States Steel Corp
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Filing: 1972-11-13
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Granted: 1974-07-30
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Expires: 1992-11-13
Abstract
Abstract A METHOD FOR DIRECTLY PRODUCING MEDIUM AND HIGH CARBON STEELS WITH LOW PHOSPHORUS CONTENTS IN A BOTTOM BLOWN BASIC STEEL REFINING PROCESS IN WHICH FINELY DIVIDED LIME IS ENTRAINED IN THE OXYGEN STREAM. THE IMPROVEMENT COMPRISES EMPLOYING AN OVERALL AVERAGE LIME LOAD RATE(LO) THROUGHOUT THE WHOLE BLOW OF ABOUT 0.09 TO 0.16LBS. LIME/FT.3 OF OXYGEN, WHEREIN THE AVERAGE RATE FOR THE FIRST HALF OF THE BLOW (L1) IS LESS THAN LO AND THE AVERAGE RATE FOR THE SECOND HALF OF THE BLOW (L2) IS GREATER THAN LO. PHOSPHORUS REDUCTION IS ADDITIONALLY ENHANCED BY DECREASING THE BLOWING TME, I.E., INCREASING THE OXYGEN BLOWING RATE.
Inventors
- 👤 D Dukelow
- 👤 P Hunter
- 👤 R King
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:34
CPC Classifications
C; C21; C21C; C21C5/00; C21C5/28; C21C5/30; C21C5/34
Claims Analysis
Total Claims: 0
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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) | 1977-07-29 | 1978-01-28 | 1978-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-29 | 1982-01-28 | 1982-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-29 | 1986-01-28 | 1986-07-30 | $7700.00 | Window Closed / Lapsed |