US2996373A
Expired / Lapsed
US
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Three-stage fluidized-reduction process
Assignee: United States Steel Corp
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Filing: 1959-03-24
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Granted: 1961-08-15
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Expires: 1979-03-24
Abstract
No abstract record available.
Inventors
- 👤 Jagdish C Agarwal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:34
CPC Classifications
C; C21; C21B; C21B13/00; C21B13/0033; B; B01; B01J; B01J8/00; B01J8/18; B01J8/24; B01J8/26; B01J8/28; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/134
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
A THREE-STEP CONTINUOUS DIRECT REDUCTION PROCESS FOR IRON OXIDE COMPRISING PASSING PREHEATED IRON OXIDE FINES THROUGH A SERIES OF THREE FLUIDIZED BEDS, PASSING PREHEATED REDUCING AND FLUIDIZED BEDS, PASSING PREHEATDDIN SERIES COUNTER TO THE IRON OXIDE, MAINTAINING A TEMPERATURE OF ABOUT 1350* TO 1550* F. IN THE FIRST BED AND ABOUT 1050* TO 1300* F. IN EACH OF THE SECOND AND THIRD BEDS, AND CONTROLLING THE REDUCTION WHICH TAKES PLACE IN EACH BED SO THAT THE PRODUCT PASSING TO THE SECOND BED IS PREDOMINANTLY FEO, THE PRODUCT DISCHARGING FROM THE THIRD BED IS PREDOMINANTLY METALLIC IRON, AND THE HEAT REQUIRED FOR THE REDUCING REACTIONS IN THE SECOND AND THIRD BEDS APPROACHES EQUALITY.
Claim 2
Dependent Claim
112 words
A THREE-STEP CONTINUOUS DIRECT REDUCTION PROCESS FOR IRON OXIDE COMPRISING PASSING PREHEATED IRON OXIDE FINES THROUGH A SERIES OF THREE FLUIDIZED BEDS, PASSING PREHEATED REDUCING AND FLUIDIZED BEDS, PASSING PREHEATDDIN SERIES COUNTER TO THE IRON OXIDE, MAINTAINING A TEMPERATURE OF ABOUT 1350* TO 1550* F. IN THE FIRST BED AND ABOUT 1050* TO 1300* F. IN EACH OF THE SECOND AND THIRD BEDS, AND CONTROLLING THE REDUCTION WHICH TAKES PLACE IN EACH BED SO THAT THE PRODUCT PASSING TO THE SECOND BED IS PREDOMINANTLY FEO, THE PRODUCT DISCHARGING FROM THE THIRD BED IS PREDOMINANTLY METALLIC IRON, AND THE HEAT REQUIRED FOR THE REDUCING REACTIONS IN THE SECOND AND THIRD BEDS APPROACHES EQUALITY.
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) | 1964-08-14 | 1965-02-13 | 1965-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-14 | 1969-02-13 | 1969-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-14 | 1973-02-13 | 1973-08-15 | $7700.00 | Window Closed / Lapsed |