US4046557A
Expired / Lapsed
US
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Method for producing metallic iron particles
Assignee: ZURICH BRANCH OF MIDREX INTERNATIONAL BV A NETHERLANDS Corp
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Filing: 1975-11-14
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Granted: 1977-09-06
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Expires: 1995-11-14
Abstract
Abstract A method of producing iron particles in a generally vertical furnace in which a gravitational flow of particulate material is reduced in a reducing zone by a countercurrent flow of a reducing gas containing a reductant, the spent reducing gas is removed and cooled and a portion is introduced as cooling gas in a cooling zone near the bottom of the furnace, and a portion of the cooling gas is upgraded in reducing potential and introduced to the reducing zone as reducing gas. Apparatus is also provided for carrying out the method.
Inventors
- 👤 Donald Beggs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:21
CPC Classifications
C; C21; C21B; C21B13/00; C21B13/02; C21B13/029; C21B2100/00; C21B2100/20; C21B2100/22; C21B2100/28; C21B2100/282; C21B2100/40; C21B2100/44; C21B2100/60; C21B2100/64; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/122; Y02P10/134
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
263 words
A method for producing a metallized product comprising: a. establishing a gravitational flow of particulate metal oxide material by charging the particulate metal oxide material to the upper portion of a generally vertical furnace having an upper reducing zone and a lower cooling zone, and removing the metallized product from the bottom of the furnace; b. introducing a reducing gas to the gravitational flow of material at a temperature sufficient to promote a reducing reaction between said reducing gas and said material at a first inlet intermediate the ends of the furnace; c. causing said reducing gas to move countercurrent through the gravitational flow of material, react with and reduce a substantial portion of the metal oxide and form a top gas; d. removing said top gas from the upper portion of the furnace; e. cooling said top gas; f. introducing a portion of said cooled top gas as cooling gas into a second inlet near the lower end of said furnace; g. removing a first portion of said cooling gas from said furnace at a location intermediate said first and second inlets; h. adding said removed portion of said cooling gas to said top gas prior to step (e); and i. causing a second portion of said cooling gas to flow upwardly through the gravitational flow of material, become heated thereby, and act as a reducing gas in the reducing zone; whereby that portion of said cooling gas flowing upwardly through the gravitational flow of material has a greater reducing potential than the spent top gas, and is thus an effective reductant.
Claim 2
Independent Claim
263 words
A method for producing a metallized product comprising: a. establishing a gravitational flow of particulate metal oxide material by charging the particulate metal oxide material to the upper portion of a generally vertical furnace having an upper reducing zone and a lower cooling zone, and removing the metallized product from the bottom of the furnace; b. introducing a reducing gas to the gravitational flow of material at a temperature sufficient to promote a reducing reaction between said reducing gas and said material at a first inlet intermediate the ends of the furnace; c. causing said reducing gas to move countercurrent through the gravitational flow of material, react with and reduce a substantial portion of the metal oxide and form a top gas; d. removing said top gas from the upper portion of the furnace; e. cooling said top gas; f. introducing a portion of said cooled top gas as cooling gas into a second inlet near the lower end of said furnace; g. removing a first portion of said cooling gas from said furnace at a location intermediate said first and second inlets; h. adding said removed portion of said cooling gas to said top gas prior to step (e); and i. causing a second portion of said cooling gas to flow upwardly through the gravitational flow of material, become heated thereby, and act as a reducing gas in the reducing zone; whereby that portion of said cooling gas flowing upwardly through the gravitational flow of material has a greater reducing potential than the spent top gas, and is thus an effective reductant.
Claim 3
Dependent Claim
15 words
A method according to claim 1 wherein said reducing gas is a reformed vaporizable hydrocarbon.
Claim 4
Dependent Claim
23 words
A method according to claim 2 wherein said hydrocarbon is selected from the group comprising natural gas, petroleum distillates, methane, ethane, propane, butane.
Claim 5
Dependent Claim
41 words
A method according to claim 1 wherein said removed and cooled top gas is separated into a first portion and a second portion, and said second portion is introduced as a fuel into a furnace containing a tube having catalyst therein.
Claim 6
Dependent Claim
37 words
A method according to claim 1 wherein said removed and cooled top gas is separated into a first portion and a second portion, and said second portion is introduced to a catalytic reformer as a reforming oxidant.
Claim 7
Dependent Claim
30 words
A method according to claim 4 wherein said second portion of said cooled top gas is mixed with a gaseous hydrocarbon to form the fuel mixture to heat said catalyst.
Claim 8
Dependent Claim
26 words
A method according to claim 5 wherein said second portion of said cooled top gas is mixed with a gaseous hydrocarbon to form reforming oxidant mixture.
Claim 9
Dependent Claim
58 words
A method according to claim 1 further comprising mixing a second portion of said cooled top gas with said reducing gas and introducing the mixture to said first inlet whereby the resulting mixture will have the proper proportion of hot reducing gas and cooled top gas to bring the temperature of the mixture to the desired inlet temperature.
Claim 10
Dependent Claim
15 words
A method according to claim 1 wherein said particulate metal oxide material is iron oxide.
Claim 11
Dependent Claim
44 words
A method according to claim 1 further comprising controlling the rate of flow of cooling gas introduced to said second inlet to maintain the temperature of the portion of said cooling gas being removed from said furnace at between about 800° to 1100° F.
Claim 12
Dependent Claim
41 words
A method according to claim 1 further comprising adding a gaseous hydrocarbon to said cooling gas prior to introducing said cooling gas into said second inlet, whereby said added gaseous hydrocarbon is reformed in the furnace to a highly effective reductant.
Claim 13
Independent Claim
177 words
A method for producing metallized pellets comprising: a. establishing a gravitational flow of metal oxide material in a vertical shaft furnace; b. introducing a gaseous reductant at an intermediate location within said furnace through a first inlet whereby the gaseous reductant moves in counterflow relationship with the descending metal oxide burden; c. removing the top gas which is the reacted gaseous reductant from the upper portion of the furnace; d. cooling said top gas; e. introducing a portion of the cooled top gas as a cooling gas directed into the vertical shaft furnace at a second inlet below said first inlet whereby said cooling gas is in direct heat exchange relationship with the descending burden; f. removing a portion of the cooling gas at an outlet intermediate to said first and second inlets; and g. adding said removed cooling gas to said removed top gas prior to step (d); whereby the cooling gas, upon reacting with the metallized burden between said second inlet and said outlet have a greater reducing potential than does the spent top gas.
Claim 14
Independent Claim
177 words
A method for producing metallized pellets comprising: a. establishing a gravitational flow of metal oxide material in a vertical shaft furnace; b. introducing a gaseous reductant at an intermediate location within said furnace through a first inlet whereby the gaseous reductant moves in counterflow relationship with the descending metal oxide burden; c. removing the top gas which is the reacted gaseous reductant from the upper portion of the furnace; d. cooling said top gas; e. introducing a portion of the cooled top gas as a cooling gas directed into the vertical shaft furnace at a second inlet below said first inlet whereby said cooling gas is in direct heat exchange relationship with the descending burden; f. removing a portion of the cooling gas at an outlet intermediate to said first and second inlets; and g. adding said removed cooling gas to said removed top gas prior to step (d); whereby the cooling gas, upon reacting with the metallized burden between said second inlet and said outlet have a greater reducing potential than does the spent top gas.
Claim 15
Dependent Claim
41 words
A method according to claim 12 further comprising adding a gaseous hydrocarbon to said cooling gas prior to introducing said cooling gas into said second inlet, whereby said added gaseous hydrocarbon is reformed in the furnace to a highly effective reductant.
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) | 1980-09-05 | 1981-03-07 | 1981-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-05 | 1985-03-07 | 1985-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-05 | 1989-03-07 | 1989-09-06 | $7700.00 | Window Closed / Lapsed |