CA2156631A1 - Method and apparatus for producing iron - Google Patents
Method and apparatus for producing ironInfo
- Publication number
- CA2156631A1 CA2156631A1 CA002156631A CA2156631A CA2156631A1 CA 2156631 A1 CA2156631 A1 CA 2156631A1 CA 002156631 A CA002156631 A CA 002156631A CA 2156631 A CA2156631 A CA 2156631A CA 2156631 A1 CA2156631 A1 CA 2156631A1
- Authority
- CA
- Canada
- Prior art keywords
- reactor
- concentrate
- slag
- post
- layer
- 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.)
- Abandoned
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 38
- 238000000034 method Methods 0.000 title claims abstract description 20
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 19
- 239000007789 gas Substances 0.000 claims abstract description 53
- 239000002893 slag Substances 0.000 claims abstract description 37
- 238000002485 combustion reaction Methods 0.000 claims abstract description 33
- 239000012141 concentrate Substances 0.000 claims abstract description 28
- 239000000155 melt Substances 0.000 claims abstract description 21
- 239000001301 oxygen Substances 0.000 claims abstract description 11
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 11
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000002184 metal Substances 0.000 claims abstract description 6
- 229910052751 metal Inorganic materials 0.000 claims abstract description 6
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 5
- 238000007664 blowing Methods 0.000 claims abstract description 3
- 239000003245 coal Substances 0.000 claims description 5
- 238000003723 Smelting Methods 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims 1
- 238000001816 cooling Methods 0.000 abstract description 3
- 235000008504 concentrate Nutrition 0.000 abstract 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 6
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 4
- 229910001882 dioxygen Inorganic materials 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000011946 reduction process Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 241001417490 Sillaginidae Species 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 239000000112 cooling gas Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000010405 reoxidation reaction Methods 0.000 description 1
- 230000009528 severe injury Effects 0.000 description 1
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
- C21B13/0006—Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B11/00—Making pig-iron other than in blast furnaces
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Electric arc furnaces ; Tank furnaces
- F27B3/10—Details, accessories or equipment, e.g. dust-collectors, specially adapted for hearth-type furnaces
- F27B3/22—Arrangements of air or gas supply devices
- F27B3/225—Oxygen blowing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D1/00—Casings; Linings; Walls; Roofs
- F27D1/12—Casings; Linings; Walls; Roofs incorporating cooling arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
- F27D17/30—Arrangements for extraction or collection of waste gases; Hoods therefor
- F27D17/304—Arrangements for extraction or collection of waste gases; Hoods therefor specially adapted for electric arc furnaces
-
- 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
- C21B2100/44—Removing particles, e.g. by scrubbing, dedusting
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Environmental & Geological Engineering (AREA)
- Manufacture Of Iron (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
- Furnace Details (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Vertical, Hearth, Or Arc Furnaces (AREA)
Abstract
Method and apparatus for producing iron by melt reduction of concen-trate or prereduced concentrate in a melt bath in a reactor, e.g. a converter (10). Concentrate and carbonaceous reducing agent are supplied to the melt bath consisting of a layer (28) of molten iron and a layer (30) of slag floatingthereon. Oxygen-containing gas, such as hot air, is blown by blowpipes (38) into a so-called post-combustion zone (37) towards the slag layer so as to combust the reducing gases being discharged and to heat the melt bath. The hot exhaust gases produced in the combustion process are led out through an outlet (12) in the roof of the reactor. The oxygen-containing gas is blown into a post-combination zone shielded from the walls of the reactor by cooling panels (42) so as to prevent the slag and metal drops splashing up during the blowing from reaching the uncooled walls (11) of the reactor in the gas phase.
Description
215~31 W094/19497 - PCT/F~4/000 METHOD AND APPARATUS FOR PRODUCING IRON
The present invention relates to a method and an apparatus for producing iron by melt reduction of concentrate or prereduced concentrate in a melt bath in a reactor, e.g.
a converter, wherein cono~ntrate or prereduced and partially molten concentrate and carbonaceous reducing agent, sùch as coal, is supplied to the melt bath consisting of a layer of molten iron and a layer of slag floating thereon; oxyge~ o"~ ing gas, such as hot air, is blown into a so-called post-c~h~tion zone by means of blowpipes towards the slag layer in order to bring about combustion of the reduction gases being ~ hArged so as to heat the melt bath; the hot exhaust gases produced are discharged through an outlet in the roof of the reactor.
Experiences ~rom experiments in various parts of the world with melt reduction of concentrate in a melt bath have shown that the wear of the tile lining in an area above and a little below the surface of the melt bath is a big problem.
In post-combustion above the slag surface, jets of preheated air or, for instance pure oxygen gas, is supplied in such a way that a vigorous agitation of the slag is brought about. Slag drops cont~;n;~g, inter alia, a high content of FeO are caused to splash up into the gas phase in the post-reduction zone. As intended, this results in a very good heat ~Y~h~nqe between hot combustion gases and slag drops. At the same time, however, a large amount of slag drops with a high content of FeO will be thrown upwards and outwards and hit the lining in the roof and the walls of the converter. The drops, the temperature of which, due to the combustion, is considerably higher than the melt bath, cause wear and destruction of the lining, and consequently, severe damage. The wear may, if it comes to the worst, be as high as 1,5 mm/h during the process, which would mean a working life of the lining of the converter of only 1200 hours.
W094/19497 ~ ~ 5 6 ~ 31 PCT/FW/OOO~
In order to prevent wear and damage, the use of cooled walls in the converters has been proposed. Converters built entirely of water-cooled panels and converters in which the tile lining has been provided with channels for cooling gas have, for instance, been used. Cooling of the whole converter, the roof as well as the walls, results, however, in high heat losses, which have to be compensated. -., It is an object of the present invention to provide animprovement of the melt reduction process and apparatus described above.
It is a particular object of the invention to reduce the wear and improve the durability of reactors such as converters in melt reduction processes.
It is a further object of the invention to provide a melt reduction process in which higher temperatures than earlier can be allowed in the post-combustion zone.
The method according to the invention is characterized in that oxygen-containing gas is blown into a post-combustion zone in the converter, which zone is shielded from the walls of the reactor by cooled panels so as to prevent the slag and metal drops splashing up during the blowing from reaching the uncooled walls of the reactor in the gas phase.
The apparatus for producing iron by melt reduction of concentrate is characterized in that a shield made of cooled panels is arranged to shield the post-combustion zone from the tile walls of the reactor or corresponding means in an area between the slag layer and the outlet for exhaust gases.
According to the invention, the post-combustion takes place in a space shielded by cooled panels from the remaining parts of the reactor. The panel or panels ~ W094/19497 215 6 6 ~1 PCTtFW/OOO~
prevent hot molten drops, which splash up into the gas phase in the post-combustion stage, from reaching the tile walls of the reactor. The panel, which may be, for instance, water-, gas- or steam-cooled, endures the wear of these drops considerably better than the uncooled tile wall. The panel can be provided with a heat-insulating layer on its outside in order to prevent unnecessary cooling in the remaining part of the reactor. In most cases a protecting layer of solidified drops is anyhow formed on the panels.
The cooled panel is preferably shaped as an upright cylinder disposed concentrically between the surface of the slag and the gas outlet. The cylinder surrounds thereby the post-combustion zone of the reactor. The cooled panel can, if needed, be widened at its upper or lower end so that the shielded zone takes the form of a frustum of cone. When air is used in the post-combustion stage, the gas volumes can be so large that it is advantageous to widen the space shielded by the panels at its lower end. The shield can have a square, rectangular or, for instance, hexagonal cross section. The shield is thus formed of plane water-cooled panels or membrane walls, which is an advantage in the manufacturing stage.
The cooled panels are preferably fastened to the roof of the reactor. If needed, openings can be provided in the upper part of the panels or between the panels and the roof of the reactor so that also gases produced outside the shielded part can flow to the gas outlet. Possibly these gases could be withdrawn from the reactor through a separate gas outlet.
,~
The lower edge of the cooled panels can in certain cases be allowed to reach the slag surface. A gap between the slag surface and the panels or the openings in the lower parts of the panels allows the gases to flow, if necessary, from the space outside the post-combustion zone via the shielded zone to the gas outlet.
The present invention relates to a method and an apparatus for producing iron by melt reduction of concentrate or prereduced concentrate in a melt bath in a reactor, e.g.
a converter, wherein cono~ntrate or prereduced and partially molten concentrate and carbonaceous reducing agent, sùch as coal, is supplied to the melt bath consisting of a layer of molten iron and a layer of slag floating thereon; oxyge~ o"~ ing gas, such as hot air, is blown into a so-called post-c~h~tion zone by means of blowpipes towards the slag layer in order to bring about combustion of the reduction gases being ~ hArged so as to heat the melt bath; the hot exhaust gases produced are discharged through an outlet in the roof of the reactor.
Experiences ~rom experiments in various parts of the world with melt reduction of concentrate in a melt bath have shown that the wear of the tile lining in an area above and a little below the surface of the melt bath is a big problem.
In post-combustion above the slag surface, jets of preheated air or, for instance pure oxygen gas, is supplied in such a way that a vigorous agitation of the slag is brought about. Slag drops cont~;n;~g, inter alia, a high content of FeO are caused to splash up into the gas phase in the post-reduction zone. As intended, this results in a very good heat ~Y~h~nqe between hot combustion gases and slag drops. At the same time, however, a large amount of slag drops with a high content of FeO will be thrown upwards and outwards and hit the lining in the roof and the walls of the converter. The drops, the temperature of which, due to the combustion, is considerably higher than the melt bath, cause wear and destruction of the lining, and consequently, severe damage. The wear may, if it comes to the worst, be as high as 1,5 mm/h during the process, which would mean a working life of the lining of the converter of only 1200 hours.
W094/19497 ~ ~ 5 6 ~ 31 PCT/FW/OOO~
In order to prevent wear and damage, the use of cooled walls in the converters has been proposed. Converters built entirely of water-cooled panels and converters in which the tile lining has been provided with channels for cooling gas have, for instance, been used. Cooling of the whole converter, the roof as well as the walls, results, however, in high heat losses, which have to be compensated. -., It is an object of the present invention to provide animprovement of the melt reduction process and apparatus described above.
It is a particular object of the invention to reduce the wear and improve the durability of reactors such as converters in melt reduction processes.
It is a further object of the invention to provide a melt reduction process in which higher temperatures than earlier can be allowed in the post-combustion zone.
The method according to the invention is characterized in that oxygen-containing gas is blown into a post-combustion zone in the converter, which zone is shielded from the walls of the reactor by cooled panels so as to prevent the slag and metal drops splashing up during the blowing from reaching the uncooled walls of the reactor in the gas phase.
The apparatus for producing iron by melt reduction of concentrate is characterized in that a shield made of cooled panels is arranged to shield the post-combustion zone from the tile walls of the reactor or corresponding means in an area between the slag layer and the outlet for exhaust gases.
According to the invention, the post-combustion takes place in a space shielded by cooled panels from the remaining parts of the reactor. The panel or panels ~ W094/19497 215 6 6 ~1 PCTtFW/OOO~
prevent hot molten drops, which splash up into the gas phase in the post-combustion stage, from reaching the tile walls of the reactor. The panel, which may be, for instance, water-, gas- or steam-cooled, endures the wear of these drops considerably better than the uncooled tile wall. The panel can be provided with a heat-insulating layer on its outside in order to prevent unnecessary cooling in the remaining part of the reactor. In most cases a protecting layer of solidified drops is anyhow formed on the panels.
The cooled panel is preferably shaped as an upright cylinder disposed concentrically between the surface of the slag and the gas outlet. The cylinder surrounds thereby the post-combustion zone of the reactor. The cooled panel can, if needed, be widened at its upper or lower end so that the shielded zone takes the form of a frustum of cone. When air is used in the post-combustion stage, the gas volumes can be so large that it is advantageous to widen the space shielded by the panels at its lower end. The shield can have a square, rectangular or, for instance, hexagonal cross section. The shield is thus formed of plane water-cooled panels or membrane walls, which is an advantage in the manufacturing stage.
The cooled panels are preferably fastened to the roof of the reactor. If needed, openings can be provided in the upper part of the panels or between the panels and the roof of the reactor so that also gases produced outside the shielded part can flow to the gas outlet. Possibly these gases could be withdrawn from the reactor through a separate gas outlet.
,~
The lower edge of the cooled panels can in certain cases be allowed to reach the slag surface. A gap between the slag surface and the panels or the openings in the lower parts of the panels allows the gases to flow, if necessary, from the space outside the post-combustion zone via the shielded zone to the gas outlet.
2 ~ S ~ ~ 3 1 PCT/F~/000~
When the invention is used in processes with prereduction and partial smelting of the supplied concentrate in a flame chamber made of cooled panels and located above the melt bath reactor, the lower part of the cooled panel walls of the flame chamber can easily be made longer so as to wholly or partly reach the slag surfac7è in the reactor.
The post-combustion zone can then be extended to the lower part of the flame chamber.
~.,.
In the process mentioned above, the oxygen-containing gas required in the post-combustion stage is preferably introduced tangentially into the converter by means of one or several blowpipes so that the hot gases flowing upwards form a vortex in the shielded part of the reactor already, thereby promoting the formation of a vortex in the flame chamber.
The invention will be described more in detail below with reference to the accompanying drawing, the single figure of which schematically illustrates a plant for melt reduction of iron concentrate according to the invention.
The illustrated plant comprises a converter 10 for melt reduction of prereduced molten concentrate. The converter is internally lined with tiles 11. The gas outlet 12 of the converter is connected to a flame chamber 14 for prereduction and smelting of concentrate. The flame chamber is provided with water-cooled membrane walls 15.
A reactor 16 having e.g. a fluidized bed is disposed on top of the flame chamber in order to preheat the concentrate.
Concentrate is introduced into the reactor chamber 17 of the reactor 16 through an inlet 18. Hot gases from the flame chamber are fed through an opening 20 into the bottom of the reactor. The concentrate is preheated by the exhaust gases in the reactor chamber and flows entrained by the upwards flowing gases via the upper part of the reactor to a particle separator 22. A portion of the 215~631 W094/19497 PCT/F~4/000~
preheated concentrate is recycled to the reactor chamber whereas another portion is passed to the flame chamber through a channel 24. Carbonaceous reducing agent 26 is at the same time introduced into the flame chamber.
The preheated concentrate is prereduced and smelts in the flame chamber and flows down to the converter for final reduction of the iron oxide in the melt bath 28, 30 of the converter. The melt bath consists of a iron layer 28 on the bottom of the converter and a slag layer 30 on top of the iron layer. Coal 32 and hot blast air 34 is introduced into the converter through openings in the bottom of the converter. Iron and slag is withdrawn through an outlet 36 in the side of the converter.
In order to increase the heat transfer to the melt bath, oxygen-containing gas, such as hot blast air, is introduced into a post-combustion zone 37 through blow-pipes 38 disposed above the surface 40 of the slag. The blast air is blown in tangentially by the blowpipes so that upwards flowing gases form a vortex and thereby promote the formation of a vortex in the flame chamber.
The blast air brings about a vigorous turbulence in the slag layer while the reducing gases are combusted developing heat. The vigorous turbulence results in a good heat transfer in the post-combustion zone between the gas phase and the slag and metal drops splashing up.
According to the invention, the post-combustion zone in the converter is shielded by cooled panels 42. The panels have been formed by extending the cooled walls 15 of the flame chamber downward into the converter.
In the process illustrated in the figure, the final reduction is effected by means of carbon dissolved in the metal layer. Hot blast air is used for the post-combustion which supplies energy to the slag layer 30 as well as the metal layer 28. The slag layer is thin in comparison with the iron layer.
WO94/19497 PCT/F~4/00023 ~
2 ~ 3 1 Other corresponding melt bath processes can use oxygen gas in a post-combustion stage, have a considerably thicker slag layer than iron layer and inject the whole amount of coal from above into the gas phase or the slag layer. In these processes the post-combustion supplies energy primarily to the expanding slag layer. Reduction is achieved by means of coke partic~es and iron drops suspended in the slag.
The use of air for post-combustion results, due to the high content of nitrogen in the air, in a lesser reoxidation of iron in comparison with processes using pure oxygen gas. 70% of the oxygen is utilized in processes which use air, whereas only 40 % of the oxygen is used in processes which use oxygen gas. Additionally, the use of air tends to dampen the formation of foam in the slag layer, which is an advantage. As the air furthermore brings about a considerably more vigorous turbulence in the slag layer, the use of air results in an intimate contact between the gas and slag phases. The use of shielded cooled surfaces around the post-combustion zone renders it possible to utilize the above mentioned vigorous turbulence in the converter.
The invention is not intended to be restricted to the above described and illustrated embodiment, in which the invention primarily is described in connection with melt reduction in a process with prereduction in a flame chamber. The invention can as well be used in various converter processes. The invention can be modified in many ways within the scope of the inventive idea defined in the appended claims.
,.
When the invention is used in processes with prereduction and partial smelting of the supplied concentrate in a flame chamber made of cooled panels and located above the melt bath reactor, the lower part of the cooled panel walls of the flame chamber can easily be made longer so as to wholly or partly reach the slag surfac7è in the reactor.
The post-combustion zone can then be extended to the lower part of the flame chamber.
~.,.
In the process mentioned above, the oxygen-containing gas required in the post-combustion stage is preferably introduced tangentially into the converter by means of one or several blowpipes so that the hot gases flowing upwards form a vortex in the shielded part of the reactor already, thereby promoting the formation of a vortex in the flame chamber.
The invention will be described more in detail below with reference to the accompanying drawing, the single figure of which schematically illustrates a plant for melt reduction of iron concentrate according to the invention.
The illustrated plant comprises a converter 10 for melt reduction of prereduced molten concentrate. The converter is internally lined with tiles 11. The gas outlet 12 of the converter is connected to a flame chamber 14 for prereduction and smelting of concentrate. The flame chamber is provided with water-cooled membrane walls 15.
A reactor 16 having e.g. a fluidized bed is disposed on top of the flame chamber in order to preheat the concentrate.
Concentrate is introduced into the reactor chamber 17 of the reactor 16 through an inlet 18. Hot gases from the flame chamber are fed through an opening 20 into the bottom of the reactor. The concentrate is preheated by the exhaust gases in the reactor chamber and flows entrained by the upwards flowing gases via the upper part of the reactor to a particle separator 22. A portion of the 215~631 W094/19497 PCT/F~4/000~
preheated concentrate is recycled to the reactor chamber whereas another portion is passed to the flame chamber through a channel 24. Carbonaceous reducing agent 26 is at the same time introduced into the flame chamber.
The preheated concentrate is prereduced and smelts in the flame chamber and flows down to the converter for final reduction of the iron oxide in the melt bath 28, 30 of the converter. The melt bath consists of a iron layer 28 on the bottom of the converter and a slag layer 30 on top of the iron layer. Coal 32 and hot blast air 34 is introduced into the converter through openings in the bottom of the converter. Iron and slag is withdrawn through an outlet 36 in the side of the converter.
In order to increase the heat transfer to the melt bath, oxygen-containing gas, such as hot blast air, is introduced into a post-combustion zone 37 through blow-pipes 38 disposed above the surface 40 of the slag. The blast air is blown in tangentially by the blowpipes so that upwards flowing gases form a vortex and thereby promote the formation of a vortex in the flame chamber.
The blast air brings about a vigorous turbulence in the slag layer while the reducing gases are combusted developing heat. The vigorous turbulence results in a good heat transfer in the post-combustion zone between the gas phase and the slag and metal drops splashing up.
According to the invention, the post-combustion zone in the converter is shielded by cooled panels 42. The panels have been formed by extending the cooled walls 15 of the flame chamber downward into the converter.
In the process illustrated in the figure, the final reduction is effected by means of carbon dissolved in the metal layer. Hot blast air is used for the post-combustion which supplies energy to the slag layer 30 as well as the metal layer 28. The slag layer is thin in comparison with the iron layer.
WO94/19497 PCT/F~4/00023 ~
2 ~ 3 1 Other corresponding melt bath processes can use oxygen gas in a post-combustion stage, have a considerably thicker slag layer than iron layer and inject the whole amount of coal from above into the gas phase or the slag layer. In these processes the post-combustion supplies energy primarily to the expanding slag layer. Reduction is achieved by means of coke partic~es and iron drops suspended in the slag.
The use of air for post-combustion results, due to the high content of nitrogen in the air, in a lesser reoxidation of iron in comparison with processes using pure oxygen gas. 70% of the oxygen is utilized in processes which use air, whereas only 40 % of the oxygen is used in processes which use oxygen gas. Additionally, the use of air tends to dampen the formation of foam in the slag layer, which is an advantage. As the air furthermore brings about a considerably more vigorous turbulence in the slag layer, the use of air results in an intimate contact between the gas and slag phases. The use of shielded cooled surfaces around the post-combustion zone renders it possible to utilize the above mentioned vigorous turbulence in the converter.
The invention is not intended to be restricted to the above described and illustrated embodiment, in which the invention primarily is described in connection with melt reduction in a process with prereduction in a flame chamber. The invention can as well be used in various converter processes. The invention can be modified in many ways within the scope of the inventive idea defined in the appended claims.
,.
Claims (11)
1. Method for producing iron by melt reduction of concentrate or prereduced concentrate in a melt bath in a reactor, e.g. a converter, wherein - concentrate or prereduced and partially molten concentrate and carbonaceous reducing agent, such as coal, is supplied to the melt bath consisting of a layer of molten iron and a layer of slag floating thereon;
- oxygen-containing gas, such as hot air, is blown into a so-called post-combustion zone by one or several blowpipes towards the slag layer so as to bring about combustion of the reduction gases being discharged and to heat the melt bath, - the hot exhaust gases produced are discharged through an outlet in the roof of the reactor, characterized in that the oxygen-containing gas is blown into the converter to a post-combustion zone which is shielded from the walls of the reactor by cooled panels so as to prevent the slag and metal drops splashing up during the blowing from reaching the uncooled walls of the reactor in the gas phase.
- oxygen-containing gas, such as hot air, is blown into a so-called post-combustion zone by one or several blowpipes towards the slag layer so as to bring about combustion of the reduction gases being discharged and to heat the melt bath, - the hot exhaust gases produced are discharged through an outlet in the roof of the reactor, characterized in that the oxygen-containing gas is blown into the converter to a post-combustion zone which is shielded from the walls of the reactor by cooled panels so as to prevent the slag and metal drops splashing up during the blowing from reaching the uncooled walls of the reactor in the gas phase.
2. Method according to claim 1, characterized in that concentrate is introduced into the rector via a flash chamber disposed concentrically above the outlet opening for exhaust gas, the exhaust gases from the reactor being passed to the flame chamber for at least partial smelting and prereduction of the concentrate in the flame chamber.
3. Method according to claim 2, characterized in that hot oxygen-containing gas is blown in tangentially so that the exhaust gases form an upward vortex in the post-combustion zone and the flame chamber.
4. Method according to claim 2, characterized in that the exhaust gases from the flame chamber are passed to a reactor disposed above the flame chamber in order to preheat concentrate to be fed into the flash chamber.
5. Method according to claim 1, characterized in that the post-combustion zone is shielded from the walls of the reactor by means of water-cooled panels.
6. Apparatus for producing iron by melt reduction of concentrate or prereduced concentrate in a melt bath in a reactor, e.g. a converter (10), the melt bath consisting of a layer (28) of molten iron and a layer (30) of slag floating thereon, and the reactor comprising - one or several inlets for concentrate or prereduced and partially molten concentrate and one or several inlets for a carbonaceous reducing agent such as coal, - one or several hot gas blowpipes (38) for introducing oxygen-containing gas, such as hot gas, into a so-called post-combustion zone in the reactor above the surface (40) of the slag so as to bring about combustion of the reduction gases being discharged and heating of the melt bath, and - at least one gas outlet (12) for the hot exhaust gases produced in the post-combustion process located in the roof of the reactor above the post-combustion zone, characterized in that - a shield made of cooled panels (42) is arranged to shield the post-combustion zone (37) from the tile walls (11) of the reactor in an area between the slag layer (30) and the outlet (12) for exhaust gases.
7. Apparatus according to claim 6, characterized in that the shield is formed of an upright cylindrical panel surface (42) disposed concentrically with the gas outlet (12).
8. Apparatus according to claim 6, characterized in that the shield is formed of a panel surface which takes the form of a frustum of cone and is disposed concentrically with the gas outlet.
9. Apparatus according to claim 6, characterized in that the shield is formed of plane panel surfaces.
10. Apparatus according to claim 6, characterized in that the upper part of the shield is disposed around the gas outlet (12) in the roof of the reactor.
11. Apparatus according to claim 6, characterized in that the lower part of the shield reaches the surface (40) of the slag.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI930864A FI93027C (en) | 1993-02-26 | 1993-02-26 | Method and apparatus for making iron |
| FI930864 | 1993-02-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2156631A1 true CA2156631A1 (en) | 1994-09-01 |
Family
ID=8537466
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002156631A Abandoned CA2156631A1 (en) | 1993-02-26 | 1994-01-21 | Method and apparatus for producing iron |
Country Status (11)
| Country | Link |
|---|---|
| EP (1) | EP0686204A1 (en) |
| JP (1) | JPH08506858A (en) |
| KR (1) | KR960701224A (en) |
| CN (1) | CN1121358A (en) |
| AU (1) | AU673049B2 (en) |
| BR (1) | BR9406272A (en) |
| CA (1) | CA2156631A1 (en) |
| FI (1) | FI93027C (en) |
| TW (1) | TW260711B (en) |
| WO (1) | WO1994019497A1 (en) |
| ZA (1) | ZA94772B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10195513A (en) * | 1996-12-27 | 1998-07-28 | Kobe Steel Ltd | Production of metallic iron |
| AUPO944697A0 (en) * | 1997-09-26 | 1997-10-16 | Technological Resources Pty Limited | A method of producing metals and metal alloys |
| AUPP442598A0 (en) * | 1998-07-01 | 1998-07-23 | Technological Resources Pty Limited | Direct smelting vessel |
| AUPP442698A0 (en) * | 1998-07-01 | 1998-07-23 | Technological Resources Pty Limited | A direct smelting process |
| WO2005103305A1 (en) * | 2004-04-26 | 2005-11-03 | Technological Resources Pty Limited | Metallurgical processing installation |
| KR101419404B1 (en) * | 2012-07-30 | 2014-07-15 | 주식회사 포스코 | Heat treatment equipment and method for heat treatment of material us the same |
| DE102020215140A1 (en) * | 2020-12-01 | 2022-06-02 | Sms Group Gmbh | Process and melting unit for pyrometallurgical melting of raw materials containing metal, residues and/or secondary residues |
| DE102020215147A1 (en) | 2020-12-01 | 2022-06-02 | Sms Group Gmbh | Process for the pyrometallurgical melting down of raw materials containing metal, residues and/or secondary residues |
| CN112725645A (en) * | 2020-12-22 | 2021-04-30 | 大冶市兴进铝业有限公司 | Novel aluminium alloy preparation device |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE7928208U1 (en) * | 1979-10-04 | 1980-01-03 | Thyssen Ag Vorm. August Thyssen Huette, 4100 Duisburg | DEVICE FOR CARRYING OUT METALLURGICAL REACTIONS IN A PAN |
| DE3427087C1 (en) * | 1984-07-19 | 1986-04-10 | Mannesmann AG, 4000 Düsseldorf | Metallurgical vessel |
| SE9103412L (en) * | 1990-11-20 | 1992-05-21 | Mitsubishi Materials Corp | STORAGE WATER-COOLED COAT FOR OVEN |
| DE4103508A1 (en) * | 1991-02-06 | 1992-08-13 | Kortec Ag | METHOD AND DEVICE FOR COOLING VESSEL PARTS FOR CARRYING OUT PYRO METHODS, IN PARTICULAR METALLURGICAL TYPE |
| AU682578B2 (en) * | 1994-02-16 | 1997-10-09 | University Of Melbourne, The | Internal refractory cooler |
-
1993
- 1993-02-26 FI FI930864A patent/FI93027C/en not_active IP Right Cessation
-
1994
- 1994-01-21 JP JP6518683A patent/JPH08506858A/en active Pending
- 1994-01-21 WO PCT/FI1994/000023 patent/WO1994019497A1/en not_active Ceased
- 1994-01-21 CA CA002156631A patent/CA2156631A1/en not_active Abandoned
- 1994-01-21 CN CN94191797A patent/CN1121358A/en active Pending
- 1994-01-21 AU AU58854/94A patent/AU673049B2/en not_active Expired - Fee Related
- 1994-01-21 EP EP94905111A patent/EP0686204A1/en not_active Withdrawn
- 1994-01-21 BR BR9406272-2A patent/BR9406272A/en unknown
- 1994-01-21 KR KR1019950703611A patent/KR960701224A/en not_active Withdrawn
- 1994-02-04 ZA ZA94772A patent/ZA94772B/en unknown
- 1994-02-17 TW TW083101316A patent/TW260711B/zh active
Also Published As
| Publication number | Publication date |
|---|---|
| FI930864A0 (en) | 1993-02-26 |
| FI93027C (en) | 1995-02-10 |
| FI930864A7 (en) | 1994-08-27 |
| AU5885494A (en) | 1994-09-14 |
| EP0686204A1 (en) | 1995-12-13 |
| BR9406272A (en) | 2002-06-18 |
| TW260711B (en) | 1995-10-21 |
| FI93027B (en) | 1994-10-31 |
| ZA94772B (en) | 1995-08-04 |
| CN1121358A (en) | 1996-04-24 |
| JPH08506858A (en) | 1996-07-23 |
| KR960701224A (en) | 1996-02-24 |
| WO1994019497A1 (en) | 1994-09-01 |
| AU673049B2 (en) | 1996-10-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |