Patent US4260412A successfully refreshed from Google Patents.
US4260412A
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Method of producing direct reduced iron with fluid bed coal gasification
Assignee: ZURICH BRANCH OF MIDREX INTERNATIONAL BV A NETHERLANDS Corp
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Filing: 1980-01-16
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Granted: 1981-04-07
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Expires: 2000-01-16
Abstract
Abstract A method of producing direct reduced iron with fluid bed coal gasification in which a portion of cooled, recycled gas is used as coolant in the gasification chamber and a second portion of the cleaned recycled gas is heated and mixed with the hot, dust-free gasification gas to form reducing gas for the direct reduction process. Limestone is preferably mixed with the pulverized coal feed to the gasification chamber to desulfurize the gas.
Inventors
- 👤 Frank V. Summers
- 👤 David C. Meissner
- 👤 John C. Scarlett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:46
CPC Classifications
C; C21; C21B; C21B13/00; C21B13/0073; C21B13/02; C21B13/029; C21B2100/00; C21B2100/40; C21B2100/42; C21B2100/60; C21B2100/64; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/122; Y02P10/134
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
183 words
A method of producing direct reduced iron with fluid bed coal gasification, comprising: (a) introducing particulate coal to a fluidized bed, ash agglomerating, gasification chamber; (b) reacting said coal at high temperature in the presence of oxygen to form a gasification gas; (c) withdrawing the gasification gas from said chamber; (d) removing particulate materials from said gasification gas; (e) mixing the dust-free gasification gas with hot, cleaned top gas from a direct reduction furnace to form a heated reducing gas; (f) introducing said heated reducing gas to a direct reduction shaft furnace to reduce the iron oxide therein to a highly metallized iron product and to form a reacted top gas; (g) withdrawing said reacted top gas from said furnace; (h) removing acid gases from said reacted top gas to produce a hydrogen and carbon monoxide rich recycle gas; (i) reheating a portion of said recycle gas prior to mixing it with said dust-free gasification gas; and (j) injecting a second portion of said cooled, cleaned recycled gas into the fluidized bed within said gasification chamber to cool the reaction within said chamber.
Claim 2
Independent Claim
183 words
A method of producing direct reduced iron with fluid bed coal gasification, comprising: (a) introducing particulate coal to a fluidized bed, ash agglomerating, gasification chamber; (b) reacting said coal at high temperature in the presence of oxygen to form a gasification gas; (c) withdrawing the gasification gas from said chamber; (d) removing particulate materials from said gasification gas; (e) mixing the dust-free gasification gas with hot, cleaned top gas from a direct reduction furnace to form a heated reducing gas; (f) introducing said heated reducing gas to a direct reduction shaft furnace to reduce the iron oxide therein to a highly metallized iron product and to form a reacted top gas; (g) withdrawing said reacted top gas from said furnace; (h) removing acid gases from said reacted top gas to produce a hydrogen and carbon monoxide rich recycle gas; (i) reheating a portion of said recycle gas prior to mixing it with said dust-free gasification gas; and (j) injecting a second portion of said cooled, cleaned recycled gas into the fluidized bed within said gasification chamber to cool the reaction within said chamber.
Claim 3
Dependent Claim
24 words
A method according to claim 1 further comprising tempering said heated recycle gas with unheated recycle gas prior to forming the reducing gas mixture.
Claim 4
Dependent Claim
19 words
A method according to claim 1 further comprising introducing a particulate sulfur acceptor to said chamber with said coal.
Claim 5
Dependent Claim
12 words
A method according to claim 3 wherein said sulfur acceptor is limestone.
Claim 6
Dependent Claim
17 words
A method according to claim 1 wherein said particulate coal is all minus 10 mm in size.
Claim 7
Dependent Claim
23 words
A method according to claim 1 further comprising cleaning and cooling said top gas after withdrawing said reacted top gas from said furnace.
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) | 1984-04-06 | 1984-10-06 | 1985-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-06 | 1988-10-06 | 1989-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-06 | 1992-10-06 | 1993-04-07 | $7700.00 | Window Closed / Lapsed |