US3320049A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reduction roasting of ore
Assignee: United States Steel Corp
•
Filing: 1964-04-27
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Granted: 1967-05-16
•
Expires: 1984-04-27
Abstract
No abstract record available.
Inventors
- 👤 Luther G Hendrickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:42
CPC Classifications
C; C21; C21B; C21B13/00; C21B13/14; C21B13/146; C01; C01G; C01G49/00; C01G49/02; C01G49/08; C21B13/08; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/134
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
148 words
A METHOD OF CONVERTING HEMATITE TO MAGNETITE COPRISING DRYING AND PREHEATING HEMAITE ORE FINES IN A FIRST KILN, CONTINUJOUSLY TRANFERRING THE FINES FROM SAID FIRST KILN TO A SECOND KILN, CONTINUOUSLY INTRODUCING FRESH REDUCING GAS AT AN ELEVATED TEMPERATURE FROM AN OUTSIDE SOURCE TO SAID SECOND KILN AND THEREBY REDUCING HEMATITE IN THE FINES TO MAGNETITE, CONTINUOUSLY TRANSFERRING THE REDUCED FINES FROM SAID SECOND KILN TO A THIRD KILN, CONINUOUSLY PASSING GAS WHICH HAS GONE THROUGH SAID SECOND KILN AND IS AT LEAST MILDLY REDUCING THROUGH SAID THIRD KILN, SAID LAST-NAMED GAS SERVING AS A COOLING MEDIUM FOR THE FINES AND PREVENTING REOXIDATION OF THE MAGNETITE, CONTINUOUSLY RECYCLING GAS FROM SAID THIRD KILN THROUGH ONE OF THE OTHER KILNS, CONTINUOUSLY PASSING GAS WHICH HAS GONE THROUGH AT LEAST ONE OTHER KILN THROUGH SAID FIRST KILN, AND BURNING IN LAST-/NAMED GAS IN SAID FIRST KILN TO SUPPLY HEAT THERETO.
Claim 2
Independent Claim
148 words
A METHOD OF CONVERTING HEMATITE TO MAGNETITE COPRISING DRYING AND PREHEATING HEMAITE ORE FINES IN A FIRST KILN, CONTINUJOUSLY TRANFERRING THE FINES FROM SAID FIRST KILN TO A SECOND KILN, CONTINUOUSLY INTRODUCING FRESH REDUCING GAS AT AN ELEVATED TEMPERATURE FROM AN OUTSIDE SOURCE TO SAID SECOND KILN AND THEREBY REDUCING HEMATITE IN THE FINES TO MAGNETITE, CONTINUOUSLY TRANSFERRING THE REDUCED FINES FROM SAID SECOND KILN TO A THIRD KILN, CONINUOUSLY PASSING GAS WHICH HAS GONE THROUGH SAID SECOND KILN AND IS AT LEAST MILDLY REDUCING THROUGH SAID THIRD KILN, SAID LAST-NAMED GAS SERVING AS A COOLING MEDIUM FOR THE FINES AND PREVENTING REOXIDATION OF THE MAGNETITE, CONTINUOUSLY RECYCLING GAS FROM SAID THIRD KILN THROUGH ONE OF THE OTHER KILNS, CONTINUOUSLY PASSING GAS WHICH HAS GONE THROUGH AT LEAST ONE OTHER KILN THROUGH SAID FIRST KILN, AND BURNING IN LAST-/NAMED GAS IN SAID FIRST KILN TO SUPPLY HEAT THERETO.
References Cited (Backward Citations)
CA674804A
Cited
US1800856A
Cited
US1832069A
Cited
US2752234A
Cited
US3005699A
Cited
US3160498A
Cited
US3160499A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-05-15 | 1970-11-14 | 1971-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-05-15 | 1974-11-14 | 1975-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-05-15 | 1978-11-14 | 1979-05-16 | $7700.00 | Window Closed / Lapsed |