US4362554A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for manufacturing sponge iron
Assignee: SKF Steel Engineering AB
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Filing: 1981-03-06
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Granted: 1982-12-07
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Expires: 2001-03-06
Abstract
Abstract Disclosed are a method and apparatus for manufacturing sponge iron by the continuous reduction of iron oxides in a shaft utilizing recirculation gases. Reaction gas is removed from the shaft furnace, substantially cleaned of all CO 2 and H 2 O, and then divided into at least two flow portions one of which is passed to a gas generator comprising a plasma burner. A reducing agent such as pit coal is injected together with an oxidant into the hot gas from the plasma burner so as to form a gas mixture comprised primarily of CO and H 2 , which gas mixture is then mixed with the other flow portion of the cleaned reaction gas in such proportion that the temperature of the resulting reduction gas is suitable for the reduction of iron oxides in the shaft furnace.
Inventors
- 👤 Sven Santen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:34
CPC Classifications
C; C21; C21B; C21B13/00; C21B13/12; C21B13/125; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/122; Y02P10/134
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
215 words
A method of manufacturing sponge iron by the continuous reduction of iron oxides in a shaft furnace comprising the steps of: (1) removing the reaction gas from a shaft furnace; (2) removing from said reaction gas substantially all CO 2 and H 2 O; (3) dividing the reaction gas into at least two flow portions; (4) passing one of said flow portions to a gas generator comprising a plasma burner and means for injecting solid reducing agent and oxidant, and heating said reaction gas by said plasma burner and injecting into the heated gas solid reducing agent and oxidant so as to form an intermediate gas mixture comprised primarily of CO and H 2 ; (5) maintaining said intermediate gas mixture at a temperature such that ash contained within the solid reducing agent forms a slag; (6) mixing said intermediate gas with at least one of said other flow portions in such proportion that the temperature of the resulting reduction gas is suitable for the reduction of iron oxides in a shaft furnace; (7) injecting said reduction gas into the lower portion of a shaft furnace and passing said reduction gas upwardly through said shaft furnace so as to reduce iron oxides contained in said furnace; and (8) removing from said furnace the reduced iron.
Claim 2
Independent Claim
215 words
A method of manufacturing sponge iron by the continuous reduction of iron oxides in a shaft furnace comprising the steps of: (1) removing the reaction gas from a shaft furnace; (2) removing from said reaction gas substantially all CO 2 and H 2 O; (3) dividing the reaction gas into at least two flow portions; (4) passing one of said flow portions to a gas generator comprising a plasma burner and means for injecting solid reducing agent and oxidant, and heating said reaction gas by said plasma burner and injecting into the heated gas solid reducing agent and oxidant so as to form an intermediate gas mixture comprised primarily of CO and H 2 ; (5) maintaining said intermediate gas mixture at a temperature such that ash contained within the solid reducing agent forms a slag; (6) mixing said intermediate gas with at least one of said other flow portions in such proportion that the temperature of the resulting reduction gas is suitable for the reduction of iron oxides in a shaft furnace; (7) injecting said reduction gas into the lower portion of a shaft furnace and passing said reduction gas upwardly through said shaft furnace so as to reduce iron oxides contained in said furnace; and (8) removing from said furnace the reduced iron.
Claim 3
Dependent Claim
13 words
A method according to claim 1 wherein said oxidant is water or oxygen.
Claim 4
Dependent Claim
24 words
A method according to claim 2 including the step of maintaining the intermediate gas mixture at a temperature between about 1300° and 1500° C.
Claim 5
Dependent Claim
46 words
A method according to claim 3 wherein said intermediate gas is mixed with said at least one other flow portion in such a proportion that the temperature of the resulting reduction gas prior to injection into the shaft furnace is between about 700° and 1000° C.
Claim 6
Dependent Claim
24 words
A method according to claim 4 wherein the temperature of the reduction gas prior to injection into the shaft furnace is approximately 825° C.
Claim 7
Dependent Claim
37 words
A method according to claim 1 wherein the CO 2 and H 2 O is removed from the reaction gas by means of a gas wash until the content of CO 2 is less than about 2%.
Claim 8
Independent Claim
15 words
A method according to any one of claims 1-6 wherein said reducing agent is coal.
Claim 9
Dependent Claim
13 words
A method according to claim 7 wherein said reducing agent is coal dust.
Claim 10
Dependent Claim
14 words
A method according to claim 8 wherein said reducing agent is pit coal dust.
Claim 11
Dependent Claim
20 words
A method according to claim 8 wherein said reducing agent is coal dust having a particle size below 20 mesh.
Claim 12
Dependent Claim
20 words
A method according to claim 10 wherein said reducing agent is coal dust having a particle size below 100 mesh.
Claim 13
Independent Claim
22 words
A method according to any one of claims 1-6 including the step of passing said intermediate gas mixture through a sulphur filter.
Claim 14
Dependent Claim
181 words
Apparatus for the manufacture of sponge iron by the continuous reduction of iron oxides comprising: (1) a shaft furnace for the reaction of iron oxides by a reduction gas comprised primarily of CO and H 2 ; (2) means connected to the upper portion of the shaft furnace for removing reaction gas from the furnace; (3) cleaning means for the removal of CO 2 from said reaction gas; (4) means for separating the cleaned reaction gas into at least two flow portions; (5) a gas generator for receiving at least one of said flow portions, said gas generator comprising a plasma burner and means for injecting solid reducing agent and oxidant into the gas heated by said plasma burner thereby to produce an intermediate gas mixture comprised primarily of CO and H 2 ; (6) mixing means for the controlled mixing of said intermediate gas mixture with at least one of the other flow portions of the reaction gas thereby to obtain a reduction gas; and (7) means for injecting said reduction gas into the lower portion of the shaft furnace.
Claim 15
Dependent Claim
181 words
Apparatus for the manufacture of sponge iron by the continuous reduction of iron oxides comprising: (1) a shaft furnace for the reaction of iron oxides by a reduction gas comprised primarily of CO and H 2 ; (2) means connected to the upper portion of the shaft furnace for removing reaction gas from the furnace; (3) cleaning means for the removal of CO 2 from said reaction gas; (4) means for separating the cleaned reaction gas into at least two flow portions; (5) a gas generator for receiving at least one of said flow portions, said gas generator comprising a plasma burner and means for injecting solid reducing agent and oxidant into the gas heated by said plasma burner thereby to produce an intermediate gas mixture comprised primarily of CO and H 2 ; (6) mixing means for the controlled mixing of said intermediate gas mixture with at least one of the other flow portions of the reaction gas thereby to obtain a reduction gas; and (7) means for injecting said reduction gas into the lower portion of the shaft furnace.
Claim 16
Dependent Claim
14 words
Apparatus according to claim 13 wherein the cleaning means comprises a CO 2 wash.
Claim 17
Dependent Claim
17 words
Apparatus according to claim 14 wherein the CO 2 wash contains mono-ethanol amine as the active agent.
Claim 18
Dependent Claim
22 words
Apparatus according to claim 13 including a compressor located between the cleaning means and the means for separating the cleaned reaction gas.
Claim 19
Dependent Claim
19 words
Apparatus according to any one of claims 13-16 wherein said gas generator is provided with means for removing slag.
Claim 20
Dependent Claim
20 words
Apparatus according to any one of claims 13-16 including a sulphur filter between the gas generator and the mixing means.
Claim 21
Dependent Claim
29 words
Apparatus according to any one of claims 13-16 wherein the means for injecting solid reducing agent and oxidant has an injection area immediately in front of the plasma burner.
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) | 1985-12-06 | 1986-06-07 | 1986-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-06 | 1990-06-07 | 1990-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-06 | 1994-06-07 | 1994-12-07 | $7700.00 | Window Closed / Lapsed |