US3955963A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of reducing ore
Assignee: Centre de Recherches Metallurgiques CRM ASBL
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Filing: 1974-05-17
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Granted: 1976-05-11
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Expires: 1994-05-17
Abstract
Abstract Ore (e.g. iron ore) and coke are fed continually into the top of a shaft furnace, and molten metal and slag collect in a hearth from which they are tapped periodically. A reducing gas at 800° to 1200°C is injected into the furnace at the bottom of the shaft, preferably into the lower part of the reserve zone. An inert gas at 1700° to 2500°C is injected into the furnace at the top of the hearth.
Inventors
- 👤 Nicolas Gerassimos Ponghis
- 👤 Arthur Gerard Poos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:11
CPC Classifications
C; C21; C21B; C21B5/00; C21B5/001; C21B5/002
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
137 words
A method of reducing ore in a furnace having a shaft comprising a stack in which a charge of ore and coke descends and a hearth below the stack in which molten metal and slag collect, the method comprising the steps of: feeding ore and coke continually into the top of the stack; tapping metal and slag continually from the hearth; continuously injecting a reducing gas at 800° to 1200°C into the lower part of the stack; and continuously injecting into the top of the hearth, a gas which is essentially chemically inert to the contents of the furnace, the inert gas being at 1700° to 2500°C, whereby the thermal requirements for melting of the slag and the metal and for chemical reactions in the furnace are satisfied by the reducing gas and the inert gas alone.
Claim 2
Independent Claim
137 words
A method of reducing ore in a furnace having a shaft comprising a stack in which a charge of ore and coke descends and a hearth below the stack in which molten metal and slag collect, the method comprising the steps of: feeding ore and coke continually into the top of the stack; tapping metal and slag continually from the hearth; continuously injecting a reducing gas at 800° to 1200°C into the lower part of the stack; and continuously injecting into the top of the hearth, a gas which is essentially chemically inert to the contents of the furnace, the inert gas being at 1700° to 2500°C, whereby the thermal requirements for melting of the slag and the metal and for chemical reactions in the furnace are satisfied by the reducing gas and the inert gas alone.
Claim 3
Dependent Claim
24 words
The method as claimed in claim 1, wherein the reducing gas is injected into the lower part of the reserve zone in the shaft.
Claim 4
Dependent Claim
29 words
The method as claimed in claim 1, in which the furnace is a blast furnace having tuyeres, the inert gas being injected at substantially the level of the tuyeres.
Claim 5
Dependent Claim
33 words
The method as claimed in claim 1, further comprising the step of raising the inert gas to be injected at the top of the hearth to 1700°-2500° C by means of a burner.
Claim 6
Dependent Claim
14 words
The method as claimed in claim 1 in which the inert gas is nitrogen.
Claim 7
Dependent Claim
33 words
The method as claimed in claim 1, further comprising the step of raising the inert gas to be injected at the top of the hearth to 1700°-2500°C by means of an electric arc.
Claim 8
Dependent Claim
33 words
The method as claimed in claim 1, further comprising the step of raising the inert gas to be injected at the top of the hearth to 1700°-2500°C by means of a plasma arc.
References Cited (Backward Citations)
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Cited
US1010490A
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US1917642A
Cited
US2559213A
Cited
US2952533A
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US3764299A
Cited
US3814404A
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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) | 1979-05-11 | 1979-11-10 | 1980-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-11 | 1983-11-10 | 1984-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-11 | 1987-11-10 | 1988-05-11 | $7700.00 | Window Closed / Lapsed |