CA1151879A - Method and apparatus for manufacturing sponge iron - Google Patents
Method and apparatus for manufacturing sponge ironInfo
- Publication number
- CA1151879A CA1151879A CA000371539A CA371539A CA1151879A CA 1151879 A CA1151879 A CA 1151879A CA 000371539 A CA000371539 A CA 000371539A CA 371539 A CA371539 A CA 371539A CA 1151879 A CA1151879 A CA 1151879A
- Authority
- CA
- Canada
- Prior art keywords
- gas
- reduction
- reducing agent
- shaft furnace
- shaft
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/0073—Selection or treatment of the reducing gases
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
- C21B2100/20—Increasing the gas reduction potential of recycled exhaust gases
- C21B2100/22—Increasing the gas reduction potential of recycled exhaust gases by reforming
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
- C21B2100/20—Increasing the gas reduction potential of recycled exhaust gases
- C21B2100/28—Increasing the gas reduction potential of recycled exhaust gases by separation
- C21B2100/282—Increasing the gas reduction potential of recycled exhaust gases by separation of carbon dioxide
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
- C21B2100/40—Gas purification of exhaust gases to be recirculated or used in other metallurgical processes
- C21B2100/42—Sulphur removal
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/122—Reduction of greenhouse gas [GHG] emissions by capturing or storing CO2
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/134—Reduction of greenhouse gas [GHG] emissions by avoiding CO2, e.g. using hydrogen
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture Of Iron (AREA)
Abstract
ABSTRACT
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 C02 and H20, and then divided into at least two flow portions one of which is passed to a gas generator comprising a gas generating shaft substantially filled with a solid reducing agent and a plasma burner arranged in the lower portion of said shaft. An oxidant is injected into the hot gas from the plasma burner so as to form a gas mixture mainly comprising CO and H2, which gas mixture is then mixed with the other flow portion of the cleaned reaction gas in such a proportion that the temperature of the resulting reduction gas is suitable for the reduction of iron oxides in the shaft furnace. The reduction gas is then injected into the shaft furnace and passed upwardly to reduce iron oxides contained there to form sponge iron which is then removed.
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 C02 and H20, and then divided into at least two flow portions one of which is passed to a gas generator comprising a gas generating shaft substantially filled with a solid reducing agent and a plasma burner arranged in the lower portion of said shaft. An oxidant is injected into the hot gas from the plasma burner so as to form a gas mixture mainly comprising CO and H2, which gas mixture is then mixed with the other flow portion of the cleaned reaction gas in such a proportion that the temperature of the resulting reduction gas is suitable for the reduction of iron oxides in the shaft furnace. The reduction gas is then injected into the shaft furnace and passed upwardly to reduce iron oxides contained there to form sponge iron which is then removed.
Description
DESC~IPTION . .
"METHOD ANI) APPARATUS E'OR_MANUFACTURING SPONGE IRO~"
~ he present invention relates to a method of, and apparatus for, manufacturing sponge iron.
Conventional processes for the manufacture of sponge iron in which a solid reducing agent, such as coke, is used as a reducing agent are primarily the following:
a. The rotary furnace method in which pit coal is used together with the ore to be reduced, in an inclined rotary furnace. The difficulty with this method is that, mainly due to kinetic energy, it is necessary to work with relatively high temperatures, preferably 1000C, which causes considerable problems with clogging and the accumulation of material in the reaction chamber.
b. The use of a shaft furnace combined with equipment for gassification of coal, which is based on partial combustion. The drawback with this known method is primarily the extremely high investment cost for the gassification equipment and also the exceptionally high energy consumption.
c. The method, such as is disclosed in Swedish Patent No. 73 oL~ 332-5, of directly gassifying coal in solid form using a plasma generator. The drawbacks of ~15~L~79 this method are that the supply of coal must be extremely accurately adjusted and for some grades of coal there are problems in handling the ash. Moreover, the gas produced has a hydrogen content which is lower S than the ideal for reduction purposes.
It has now been found that the above difficulties and drawbacks with the known processes can be substantially eliminated according to the present invention. This invention is directed to a method and apparatus for manufacturing sponge iron by the continuous reduction of iron oxides in a shaft furnace~ The method of the present invention comprises the following steps:
1) removing reaction gas from a shaft furnace;
"METHOD ANI) APPARATUS E'OR_MANUFACTURING SPONGE IRO~"
~ he present invention relates to a method of, and apparatus for, manufacturing sponge iron.
Conventional processes for the manufacture of sponge iron in which a solid reducing agent, such as coke, is used as a reducing agent are primarily the following:
a. The rotary furnace method in which pit coal is used together with the ore to be reduced, in an inclined rotary furnace. The difficulty with this method is that, mainly due to kinetic energy, it is necessary to work with relatively high temperatures, preferably 1000C, which causes considerable problems with clogging and the accumulation of material in the reaction chamber.
b. The use of a shaft furnace combined with equipment for gassification of coal, which is based on partial combustion. The drawback with this known method is primarily the extremely high investment cost for the gassification equipment and also the exceptionally high energy consumption.
c. The method, such as is disclosed in Swedish Patent No. 73 oL~ 332-5, of directly gassifying coal in solid form using a plasma generator. The drawbacks of ~15~L~79 this method are that the supply of coal must be extremely accurately adjusted and for some grades of coal there are problems in handling the ash. Moreover, the gas produced has a hydrogen content which is lower S than the ideal for reduction purposes.
It has now been found that the above difficulties and drawbacks with the known processes can be substantially eliminated according to the present invention. This invention is directed to a method and apparatus for manufacturing sponge iron by the continuous reduction of iron oxides in a shaft furnace~ The method of the present invention comprises the following steps:
1) removing reaction gas from a shaft furnace;
2) removing from the reaction gas substantially all C02 and H2O;
3) dividing the rea~tion gas into at least two flow portions;
4) passing one of the flow portions to a gas generator comprising a gas generating shaft substantial]y filled with a solid reducing agent, a plasma burner arranged in the lower portion of said shaft, and means for injecting oxidant, heating the reaction gas with the plasma burner and injecting into the hea-ted gas from the plasma burner an oxidant to form an intermediate gas 2~ mixture mainly comprising C~ and H2;
S) maintaining the intermediate gas mixture ii3L87'~
at a temperature such that ash contained within the solid reducing agent ~orms a slag, 6) forming a reduction gas by mixing the intermediate gas mixture with at least one of the other flow portions in such a proportion that the temperature of the reduction gas is suitable for the reduction of iron oxides in a sha-ft furnace, 7) injecting the reduction gas into the lower portion of a shaft furnace and passing the reduction gas upwardly through the shaft furnace to reduce iron oxides contained in the furnace and produce further reaction gas, and removing reduced iron from the furnace.
In the present method, a reduction gas is passed counter-current to the iron oxides and consists primarily of CO and H2, the reduction gas being produced from recirculation gas, i.e. reaction gas leaving the shaft furnace, as well as an extra gas produced from solid reducing agent with the help of a plasma generatorO
The recirculation or reaction gas is first substantially cleaned CO2 and H2O, whereupon the gas thus cleaned is divided into at least two portions, one of which is passed to a gas or plasma generator~ The gas generator comprises a gas generating shaft su~stantially filled with a solid reducing agent such as coke. A plasma burner is arranged in the lower portion of the generating ~L~ 5~
shaft and an oxidant such as water and/or oxygen gas is injected into the hot gas flow leaving -the plasma burner so that the oxidant is caused to react with the reducing agent to form a mixture of primarily C0 and H2.
The temperature level of the gas produced is kept within such a range that ash included in the solid reducing agent forms a slag~ The hot C0-H2 mixture leaving the gas generator is mixed with at least some of the other c~eaned recirculation or reaction gas in such a proportion that the temperature of the final gas mixture is suitable for the reduction process.
Preferably, the tempera-ture level of the gas produced in the gas generating shaft, i.e~ the intermediate gas mixture, is adjustedto a temperature of 1300-1500C.
It is also preferable, before the final gas mixture is provided as reduction gas to the lower part of the shaft furnace, for its temperature to be brought to within the range 700 - 1000C by mixing it with the second flow portion.
The recirculation or reaction gas is preferably cleaned in a gas wash until its content of C02 is below 2%.
The present invention also provides an apparatus for the manufacture of sponge iron comprising:
1) a shaft furnace for the reduction of iron oxides by a reduction gas mainly comprising C0 and H2, , ., ' ' .
' -.
~15~8 2~ means connected to the upper portion of the shaft furnace for removing reaction gas from the fuxnace;
3) cleaning means for the removal of CO2 from the reaction gas;
4) means for separating the cleaned reac-tion gas into at least two flow portions,
S) maintaining the intermediate gas mixture ii3L87'~
at a temperature such that ash contained within the solid reducing agent ~orms a slag, 6) forming a reduction gas by mixing the intermediate gas mixture with at least one of the other flow portions in such a proportion that the temperature of the reduction gas is suitable for the reduction of iron oxides in a sha-ft furnace, 7) injecting the reduction gas into the lower portion of a shaft furnace and passing the reduction gas upwardly through the shaft furnace to reduce iron oxides contained in the furnace and produce further reaction gas, and removing reduced iron from the furnace.
In the present method, a reduction gas is passed counter-current to the iron oxides and consists primarily of CO and H2, the reduction gas being produced from recirculation gas, i.e. reaction gas leaving the shaft furnace, as well as an extra gas produced from solid reducing agent with the help of a plasma generatorO
The recirculation or reaction gas is first substantially cleaned CO2 and H2O, whereupon the gas thus cleaned is divided into at least two portions, one of which is passed to a gas or plasma generator~ The gas generator comprises a gas generating shaft su~stantially filled with a solid reducing agent such as coke. A plasma burner is arranged in the lower portion of the generating ~L~ 5~
shaft and an oxidant such as water and/or oxygen gas is injected into the hot gas flow leaving -the plasma burner so that the oxidant is caused to react with the reducing agent to form a mixture of primarily C0 and H2.
The temperature level of the gas produced is kept within such a range that ash included in the solid reducing agent forms a slag~ The hot C0-H2 mixture leaving the gas generator is mixed with at least some of the other c~eaned recirculation or reaction gas in such a proportion that the temperature of the final gas mixture is suitable for the reduction process.
Preferably, the tempera-ture level of the gas produced in the gas generating shaft, i.e~ the intermediate gas mixture, is adjustedto a temperature of 1300-1500C.
It is also preferable, before the final gas mixture is provided as reduction gas to the lower part of the shaft furnace, for its temperature to be brought to within the range 700 - 1000C by mixing it with the second flow portion.
The recirculation or reaction gas is preferably cleaned in a gas wash until its content of C02 is below 2%.
The present invention also provides an apparatus for the manufacture of sponge iron comprising:
1) a shaft furnace for the reduction of iron oxides by a reduction gas mainly comprising C0 and H2, , ., ' ' .
' -.
~15~8 2~ means connected to the upper portion of the shaft furnace for removing reaction gas from the fuxnace;
3) cleaning means for the removal of CO2 from the reaction gas;
4) means for separating the cleaned reac-tion gas into at least two flow portions,
5) a gas generator for receiving at least one of the flow portions, said gas generator comprising a gas generating shaft substantially filled with a solid reducing agent, a plasma burner arranged in the lower portion of the gas generating shaft, and means for injecting oxidant into gas heated by the plasma burner thereby to produce an intermediate gas mixture mainly comprising CO and M2;
6) mixing means for the controlled mixing of the intermediate gas mixture with at least one of the other flow portions of the reaction gas to obtain a reduction gas; and
7) means for injecting the reduction gas into the lower portion of the shaft furnace.
Illustrative embodiments of the present invention will now be described, by way of example, with reference to the single figure of the accompanying drawi~g which illustrates dia~rammatically a mode of carrying out the invention.
-,. . ,. .
- .. ~ ............ , , . :
In the drawing, the reduction of chunks of iron oxide is performed in a reduction shaft furnace 1. The chur~s of iron oxide 2 are fed -through a sluice valve 3 into the shaft furnace 1 and treated b~ a counter-curren-t ' flow of a hot reduction gas consisting primarily of carbon monoxide and hydrogen gas introduced by blowing means at the lower section 4 of the shaft furnace 1. The sponge iron product'is removed through an outlet 5 in the bottom 4 of the shaft furnace 1. The reac-tion gas, 30%
to 50% of which has been reacted, is removed from the upper par,t of the shaft furnace 1 through an outlet 6.
The gas thus removed from the shaft furnace 1, besides containing from 50/0 to 70% unreacted CO and H2, . also contains the reaction products C02 and H20. Since 1.5 this gas still contains relatively high percentages of CO and H2, it is re-usable in the process. However, to enable it to be re-used as reduction gas, the content of C2 and H20 should be reduced preferably to less than 5%.
This is achieved by allowing the gas -to pass through a wash (C02/H20 wash) 7. When the gas passes through this wash, not only is it freed from the reaction products C2 and H20, but the actual washing process enables balancing of the gas quantity so that flaring of the gas .can be avoided. The wash 7 may contain mono-ethanolamine, for instance, as active substance and the content of C02 in the gas can be suitably reduced to below 2% upon passage -15~
through the wash.
- After the wash 7 the gas p~asses a compressor
Illustrative embodiments of the present invention will now be described, by way of example, with reference to the single figure of the accompanying drawi~g which illustrates dia~rammatically a mode of carrying out the invention.
-,. . ,. .
- .. ~ ............ , , . :
In the drawing, the reduction of chunks of iron oxide is performed in a reduction shaft furnace 1. The chur~s of iron oxide 2 are fed -through a sluice valve 3 into the shaft furnace 1 and treated b~ a counter-curren-t ' flow of a hot reduction gas consisting primarily of carbon monoxide and hydrogen gas introduced by blowing means at the lower section 4 of the shaft furnace 1. The sponge iron product'is removed through an outlet 5 in the bottom 4 of the shaft furnace 1. The reac-tion gas, 30%
to 50% of which has been reacted, is removed from the upper par,t of the shaft furnace 1 through an outlet 6.
The gas thus removed from the shaft furnace 1, besides containing from 50/0 to 70% unreacted CO and H2, . also contains the reaction products C02 and H20. Since 1.5 this gas still contains relatively high percentages of CO and H2, it is re-usable in the process. However, to enable it to be re-used as reduction gas, the content of C2 and H20 should be reduced preferably to less than 5%.
This is achieved by allowing the gas -to pass through a wash (C02/H20 wash) 7. When the gas passes through this wash, not only is it freed from the reaction products C2 and H20, but the actual washing process enables balancing of the gas quantity so that flaring of the gas .can be avoided. The wash 7 may contain mono-ethanolamine, for instance, as active substance and the content of C02 in the gas can be suitably reduced to below 2% upon passage -15~
through the wash.
- After the wash 7 the gas p~asses a compressor
8 to achieve a desirable pressure increase for the process and is then divided into a-t least two flow portions 9, 10.
The flow portion 9, which is at room temperature, is introduced under control into a gas generator 11 where the necessary extra gas is generated from a solid reducing agent, preferably coke, and an oxidant, preferably water and/or oxygen gas. The gas flow 9 is used as plasma gas in gas generator 11 and the quantity of energy necessary for the gas generating process is supplied in a plasma burner 12. The gas generator 11 is substantially filled with a solid reducing agent, preferably coke. An oxidant, preferably water and~or oxygen gas, is supplied to the gas generator 11 through jets 13 so that it penetrates the hot gas flow leaving the plasma burner 12. Extra reducing agent may optionally be added, for example in powder form through injector means 13a. Thls additional reducing agent is preferably coal dust having a particle size below 20 mesh and preferably below 100 mesh (U.S.
Standard screen sizes). The hot gas flow from the plasma burner is thus caused to act upon the reducing agent and form C0 and H2.
The supply of energy in the gas generator 11 is regulated so that the ash existing in the coal dust is melted to a slag 14 which can be removed from the lower part of the gas generator 11 in liquid or solid form via tapping means 16. Due to the composition of the ash, the tempera-ture is preferably selected to be within the range 1300 - 1500C.
~he gas produced in the gas generator 11, besides containing C0 and ~I2, may also contain sulphur from the reducing agent. This intermediate gas mixture is therefore caused to pass a sulphur filter 15 (e.g. a dolomite filter) where the sulphur content is reduced to an acceptable level for the sponge iron process, preferably below 75 ppm.
According to an alternative embodimen~ of the invention, the sulphur filter 15 may be built into the gas generator itself, by providing the coke bed with suitable m~terial for the purpose.
The gas leaving the sulphur filter 15 is at a temperature substantially in excess of that re~uired for the sponge iron process and the temperature is therefore suitably lowered by using an adjustable mixer to mix in a suitable portion of the cold, untreated cleaned reaction gas in the flow portion 10 to yield a temperature suitable for the process - e.g. from 700C, preferably 750C, up to 1000C, more preferably about 825C. While separate mixing means can be used to mix the gas from the gas generator and the flow portion 10, it is also possible to introduce part or all of the flow portion 10 into the top of the gas generator 11 such that the gas generator is used as a mixing chamber~
.
.
~:~S~7~
g Substantial technical advantages are obtained utilizing the method and apparatus according to the invention. In this regard, the gas generation can take place at a temperature such that the ash forms slag which is ~asy to handle and which can be tapped off without causing clogging problems in the process. The hydrogen content in the reduction gas can be adjusted to an amount - suitable for the reduction process by means of the washing process and subsequent injection of water and/or oxygen gas into the gas generator. Furthermore the combina-tion of gas washing and gas generation at increased temperatures offers superior possibilities of balancing the quantity of gas in the system and regulating the reduction temperature. At the same time, energy efficiency is achieved since the energy supplied by the gas or plasma generator is substantially completely used in the process (i.e. temperature adjustment is accomplished by adding~
cooler recycled reduction gas rather than by removing heat from the system).
Should difficulties arise in binding -the ash from the solid reducing agent in a slag phase, additives affecting the properties ~e~g. melting point, sulphur absorption, etc~) of the slag may be used, such as alkali compounds and chalkO These additives are preferably mixed with the solid reducing agent.
The flow portion 9, which is at room temperature, is introduced under control into a gas generator 11 where the necessary extra gas is generated from a solid reducing agent, preferably coke, and an oxidant, preferably water and/or oxygen gas. The gas flow 9 is used as plasma gas in gas generator 11 and the quantity of energy necessary for the gas generating process is supplied in a plasma burner 12. The gas generator 11 is substantially filled with a solid reducing agent, preferably coke. An oxidant, preferably water and~or oxygen gas, is supplied to the gas generator 11 through jets 13 so that it penetrates the hot gas flow leaving the plasma burner 12. Extra reducing agent may optionally be added, for example in powder form through injector means 13a. Thls additional reducing agent is preferably coal dust having a particle size below 20 mesh and preferably below 100 mesh (U.S.
Standard screen sizes). The hot gas flow from the plasma burner is thus caused to act upon the reducing agent and form C0 and H2.
The supply of energy in the gas generator 11 is regulated so that the ash existing in the coal dust is melted to a slag 14 which can be removed from the lower part of the gas generator 11 in liquid or solid form via tapping means 16. Due to the composition of the ash, the tempera-ture is preferably selected to be within the range 1300 - 1500C.
~he gas produced in the gas generator 11, besides containing C0 and ~I2, may also contain sulphur from the reducing agent. This intermediate gas mixture is therefore caused to pass a sulphur filter 15 (e.g. a dolomite filter) where the sulphur content is reduced to an acceptable level for the sponge iron process, preferably below 75 ppm.
According to an alternative embodimen~ of the invention, the sulphur filter 15 may be built into the gas generator itself, by providing the coke bed with suitable m~terial for the purpose.
The gas leaving the sulphur filter 15 is at a temperature substantially in excess of that re~uired for the sponge iron process and the temperature is therefore suitably lowered by using an adjustable mixer to mix in a suitable portion of the cold, untreated cleaned reaction gas in the flow portion 10 to yield a temperature suitable for the process - e.g. from 700C, preferably 750C, up to 1000C, more preferably about 825C. While separate mixing means can be used to mix the gas from the gas generator and the flow portion 10, it is also possible to introduce part or all of the flow portion 10 into the top of the gas generator 11 such that the gas generator is used as a mixing chamber~
.
.
~:~S~7~
g Substantial technical advantages are obtained utilizing the method and apparatus according to the invention. In this regard, the gas generation can take place at a temperature such that the ash forms slag which is ~asy to handle and which can be tapped off without causing clogging problems in the process. The hydrogen content in the reduction gas can be adjusted to an amount - suitable for the reduction process by means of the washing process and subsequent injection of water and/or oxygen gas into the gas generator. Furthermore the combina-tion of gas washing and gas generation at increased temperatures offers superior possibilities of balancing the quantity of gas in the system and regulating the reduction temperature. At the same time, energy efficiency is achieved since the energy supplied by the gas or plasma generator is substantially completely used in the process (i.e. temperature adjustment is accomplished by adding~
cooler recycled reduction gas rather than by removing heat from the system).
Should difficulties arise in binding -the ash from the solid reducing agent in a slag phase, additives affecting the properties ~e~g. melting point, sulphur absorption, etc~) of the slag may be used, such as alkali compounds and chalkO These additives are preferably mixed with the solid reducing agent.
Claims (21)
1. A method of manufacturing sponge iron by continuous reduction of iron oxides in a shaft furnace utilising recirculation furnace gases, which process comprises:
1) removing reaction gas from a shaft furnace, 2) removing from the reaction gas substantially all CO2 and H2O;
3) dividing the reaction gas into at least two flow portions;
4) passing one of the flow portions to a gas generator comprising a gas generating shaft substantially filled with a solid reducing agent, a plasma burner arranged in the lower portion of said shaft, and means for injecting oxidant, heating the reaction gas with the plasma burner and injecting into the heated gas from the plasma burner an oxidant to form an intermediate gas mixture mainly comprising CO and H2;
5) maintaining the intermediate gas mixture at a temperature such that ash contained within the solid reducing agent forms a slag;
6) forming a reduction gas by mixing the intermediate gas mixture with at least one of the other flow portions in such a proportion that the temperature of the reduction gas is suitable for the reduction of iron oxides in a shaft furnace, 7) injecting the reduction gas into the lower portion of a shaft furnace and passing the reduction gas upwardly through the shaft furnace to reduce iron oxides contained in the furnace and produce further reaction gas, and 8) removing reduced iron from the -furnace.
1) removing reaction gas from a shaft furnace, 2) removing from the reaction gas substantially all CO2 and H2O;
3) dividing the reaction gas into at least two flow portions;
4) passing one of the flow portions to a gas generator comprising a gas generating shaft substantially filled with a solid reducing agent, a plasma burner arranged in the lower portion of said shaft, and means for injecting oxidant, heating the reaction gas with the plasma burner and injecting into the heated gas from the plasma burner an oxidant to form an intermediate gas mixture mainly comprising CO and H2;
5) maintaining the intermediate gas mixture at a temperature such that ash contained within the solid reducing agent forms a slag;
6) forming a reduction gas by mixing the intermediate gas mixture with at least one of the other flow portions in such a proportion that the temperature of the reduction gas is suitable for the reduction of iron oxides in a shaft furnace, 7) injecting the reduction gas into the lower portion of a shaft furnace and passing the reduction gas upwardly through the shaft furnace to reduce iron oxides contained in the furnace and produce further reaction gas, and 8) removing reduced iron from the -furnace.
2. A method according to claim 1 wherein the oxidant is water or oxygen.
3. A method according to claim 2, wherein, in step 5),the intermediate gas mixture is maintained at 1300° to 1500°C.
4. A method according to claim 3, wherein,in step 6),the intermediate gas mixture is mixed with 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 700° to 1000°C.
5. A method according to claim 4, wherein the temperature of the reduction gas prior to injection into the shaft furnace is approximately 825°C.
6. A method according to claim 1, wherein, in step 2), C02 and H20 is removed from the reaction gas by means of a gas wash until the content of C02 is less than 2%.
7. A method according to any one of claims 1 to 3 wherein the reducing agent is coke.
8. A method according to claim 1, wherein additional reducing agent is injected into the heated gas from the plasma burner.
9, A method according to claim 8, wherein the additional reducing agent is coal dust having a particle size below 20 mesh.
10. A method according to claim 9, wherein the particle size is below 100 mesh.
11. A method according to any one of claims 1 to 3, wherein the intermediate gas mixture is passed through a sulphur filter.
12. Apparatus for the manufacture of sponge iron by the continuous reduction of iron oxides comprising:
1) a shaft furnace for the reduction of iron oxides by a reduction gas mainly comprising CO and H2;
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 CO2 from the 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 the flow portions, said gas generator comprising a gas generating shaft substantially filled with a solid reducing agent, a plasma burner arranged in the lower .
portion of the gas generating shaft, and means for injecting oxidant into gas heated by the plasma burner thereby to produce an intermediate gas mixture mainly comprising CO and H2, 6) mixing means for the controlled mixing of the intermediate gas mixture with at least one of the other flow portions of the reaction gas to obtain a reduction gas, and 7) means for injecting the reduction gas into the lower portion of the shaft furnace.
1) a shaft furnace for the reduction of iron oxides by a reduction gas mainly comprising CO and H2;
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 CO2 from the 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 the flow portions, said gas generator comprising a gas generating shaft substantially filled with a solid reducing agent, a plasma burner arranged in the lower .
portion of the gas generating shaft, and means for injecting oxidant into gas heated by the plasma burner thereby to produce an intermediate gas mixture mainly comprising CO and H2, 6) mixing means for the controlled mixing of the intermediate gas mixture with at least one of the other flow portions of the reaction gas to obtain a reduction gas, and 7) means for injecting the reduction gas into the lower portion of the shaft furnace.
13. Apparatus according to claim 12, wherein the cleaning means comprises a C02 wash.
14. Apparatus according to claim 13, wherein the C02 wash contains mono-ethanolamine as the active agent.
15. Apparatus according to claim 12, 13 or 14, including a compressor located between the cleaning means and the means for separating the cleaned reaction gas.
16. Apparatus according to claim 12, 13 or 14, wherein the gas generator is provided with means for slag.
17. Apparatus according to claim 12, 13 or 14, including a sulphur filter between the gas generator and the mixing means.
18. Apparatus according to claim 12, 13 or 14, wherein a sulphur filter is incorporated in the gas generator.
19. Apparatus according to claim 12 including means for injecting additional solid reducing agent in powder form into the heated gas from the plasma burner.
20. Apparatus according to claim 19, wherein the means for injecting additional solid reducing agent has an injection area immediately in front of the plasma burner.
21. Apparatus according to claim 12, 13 or 14, wherein the means for injecting oxidant has an injection area immediately in front of the plasma burner.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000371539A CA1151879A (en) | 1981-02-23 | 1981-02-23 | Method and apparatus for manufacturing sponge iron |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000371539A CA1151879A (en) | 1981-02-23 | 1981-02-23 | Method and apparatus for manufacturing sponge iron |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1151879A true CA1151879A (en) | 1983-08-16 |
Family
ID=4119274
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000371539A Expired CA1151879A (en) | 1981-02-23 | 1981-02-23 | Method and apparatus for manufacturing sponge iron |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1151879A (en) |
-
1981
- 1981-02-23 CA CA000371539A patent/CA1151879A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| SU1052165A3 (en) | Method for reducing iron oxide | |
| KR101612305B1 (en) | Method and system for energy-optimized and carbon dioxide emission-optimized iron production | |
| US4913733A (en) | Process for producing pig iron | |
| CN103261446B (en) | Method and apparatus for producing direct reduced iron utilizing a source of reducing gas comprising hydrogen and carbon monoxide | |
| US5618032A (en) | Shaft furnace for production of iron carbide | |
| US5613997A (en) | Metallurgical process | |
| US4246024A (en) | Method for the gaseous reduction of metal ores using reducing gas produced by gasification of solid or liquid fossil fuels | |
| MX2007001249A (en) | Method and apparatus for producing clean reducing gases from coke oven gas. | |
| KR850001211B1 (en) | Method of manufacturing chromium steel | |
| CA1049792A (en) | Process and apparatus for producing molten iron | |
| CA1309589C (en) | Method of producing a clean gas containing carbon monoxide and hydrogen | |
| CA1265340A (en) | Carbon gasification | |
| JPH0471963B2 (en) | ||
| US4062529A (en) | Apparatus for the direct reduction of iron ore to sponge iron | |
| US3909244A (en) | Process for directly reducing iron ores in the solid state under pressure | |
| US4362554A (en) | Method and apparatus for manufacturing sponge iron | |
| US4439233A (en) | Direct reduction of iron | |
| US4591381A (en) | Process of producing pig iron from iron ore concentrate | |
| SU1609456A3 (en) | Method of direct production of iron | |
| CA1151879A (en) | Method and apparatus for manufacturing sponge iron | |
| US4362555A (en) | Method and apparatus for manufacturing sponge iron | |
| JPS649376B2 (en) | ||
| GB2093070A (en) | Manufacturing sponge iron | |
| CA1154262A (en) | Method and apparatus for manufacturing sponge iron | |
| GB2092617A (en) | Manufacturing sponge iron |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |