CA1074124A - Sponge iron production process - Google Patents
Sponge iron production processInfo
- Publication number
- CA1074124A CA1074124A CA243,262A CA243262A CA1074124A CA 1074124 A CA1074124 A CA 1074124A CA 243262 A CA243262 A CA 243262A CA 1074124 A CA1074124 A CA 1074124A
- Authority
- CA
- Canada
- Prior art keywords
- reaction zone
- gas
- sponge iron
- iron
- treated
- 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
Landscapes
- Manufacture Of Iron (AREA)
Abstract
SPONGE IRON PRODUCTION PROCESS
ABSTRACT OF THE DISCLOSURE
This invention relates to sponge iron production.
Iron oxide is reduced by reducer gas containing, for example, hydrogen and carbon monoxide, in a reaction zone to give the sponge iron product and a gaseous product. The latter is treated to reduce the quantity of oxidising gases, e.g. water vapour and carbon dioxide, therein and the thus treated gaseous product is recycled to the reaction zone. In this way the gases passing through the reaction zone can have a lower content of water vapour and carbon dioxide than the initial reducer gas promoting the production of sponge iron.
ABSTRACT OF THE DISCLOSURE
This invention relates to sponge iron production.
Iron oxide is reduced by reducer gas containing, for example, hydrogen and carbon monoxide, in a reaction zone to give the sponge iron product and a gaseous product. The latter is treated to reduce the quantity of oxidising gases, e.g. water vapour and carbon dioxide, therein and the thus treated gaseous product is recycled to the reaction zone. In this way the gases passing through the reaction zone can have a lower content of water vapour and carbon dioxide than the initial reducer gas promoting the production of sponge iron.
Description
L~
SPONGE IRON PRODI~CTION PROCESS
This inven-tion relates -to the production o~ sponge iron from iron ores. More particularly it relates to the production of sponge iron by reducing iron ores such as haematite (Fe2O3), liminote (2Fe2O33~2O) and magnetite (Fe3O~) in a shaft kiln.
: Sponge iron is a porous granular material and can be produced in shaft kilns by reducing iron ores with a carbon , monoxide and hydrogen reducer gas. This process has advantages 10 over conventional blast furnace methods of producing pig iron in that it can be operated commercially on a smaller scale and without the necessity of providing metallurgical coke.
The carbon monoxide and hydrogen reducer gas can be produced, for example, by reacting the methane in natural gas with steam in the presence of a catalyst, and when iron ores are treated with this reducer gas, water vapour and carbon dioxide are produced.' In practice only a relatively small proportion of the carbon monoxide and hydrogen takes part in the reduction reaction and clearly it would be desirable to ,' 20 utilise these gases more efficiently.
Normally, the reducer gas produced in the above described manner contains small amounts of water vapour and carbon dioxide. The presence,of these gases in the reaction , ' zone of the kiln has the chemical effect of decreasing slightly "
the tendency of the iron oxide and carbon monoxide and hydrogen to react to produce the sponge iron as will be hereinafter described in more detail. Therefore, the efficiency of the process and yield of sponge iron would be improved if the quantity of carbon dioxide and water vapour introduced into 30 the reaction~zone could be kept to the minimum. ~' The invention has been made with these points in mind.
SPONGE IRON PRODI~CTION PROCESS
This inven-tion relates -to the production o~ sponge iron from iron ores. More particularly it relates to the production of sponge iron by reducing iron ores such as haematite (Fe2O3), liminote (2Fe2O33~2O) and magnetite (Fe3O~) in a shaft kiln.
: Sponge iron is a porous granular material and can be produced in shaft kilns by reducing iron ores with a carbon , monoxide and hydrogen reducer gas. This process has advantages 10 over conventional blast furnace methods of producing pig iron in that it can be operated commercially on a smaller scale and without the necessity of providing metallurgical coke.
The carbon monoxide and hydrogen reducer gas can be produced, for example, by reacting the methane in natural gas with steam in the presence of a catalyst, and when iron ores are treated with this reducer gas, water vapour and carbon dioxide are produced.' In practice only a relatively small proportion of the carbon monoxide and hydrogen takes part in the reduction reaction and clearly it would be desirable to ,' 20 utilise these gases more efficiently.
Normally, the reducer gas produced in the above described manner contains small amounts of water vapour and carbon dioxide. The presence,of these gases in the reaction , ' zone of the kiln has the chemical effect of decreasing slightly "
the tendency of the iron oxide and carbon monoxide and hydrogen to react to produce the sponge iron as will be hereinafter described in more detail. Therefore, the efficiency of the process and yield of sponge iron would be improved if the quantity of carbon dioxide and water vapour introduced into 30 the reaction~zone could be kept to the minimum. ~' The invention has been made with these points in mind.
- 2 -: -' ' , ' :' ' ~ ccording to the invention there is provided a method of producing sponge iron in which an iron oxide is reduced with a reducer gas such as carbon monoxide and hydrogen, at least a port~on of the gaseous reaction product is treated to at least reduce the quantity of oxidising gases, such as carbon dioxide and water vapour in it, and at least a portion of the treated gaseous reaction products is passed either directly or indirectly back into the reaction zone. Preferably, that portion of the treated gaseous reaction products to be passed back into the reaction zone is heated.
The process can be effected, for example, in a shaft kiln.
The method according to the invention has the advantage that the carbon monoxide and hydrogen reducer gas is utilised more efficiently. Furthermore, since the treated gaseous reaction products cGntain reduced quantities of, or substantially no, carbon dioxide and water vapour, their presence in the reaction zone tends to reduce the total quantity of carbon dioxide and water vapour in that zone as compared with the total quantity present where only reducer gas is introduced into the reaction zone. Therefore, the efficiency of the reduction reaction and consequently the yields of sponge iron will be improved.
The treated gaseous reaction products preferably contain substantially no water vapour and carbon dioxide and are preferably divided into two or more gas streams. One of these can be heated and passed back into the reaction zone, another may be used as a tempering stream for mixing with the main reducer gas stream being fed to the reaction zone to control the 'temperature of that stream, and yet another may be used to fire the reformer for producing the reducer gas .
'' ` ` ~
~7L~
although instead of this a stream of cooled gaseous reaction product before removal of the carbon dioxide and water vapour may be used. Any number of streams may be provided.
The separation of the treated gases into gas streams in this manner has the advantage that the temperature of the reducer gas being fed to the reaction zone can be very effect-ively controlled. This is important because, if the temperature of the reducer gas is too high, iron oxide particles will agglo-merate in the reaction zone. On the other hand if the tempera-ture is too low the efficiency of the reaction will be deleteri-ously affected. The optimum temperature is believed to be about 850 to 900C and this temperature can be malntained by varying the amount of tempering gas mixed with the reducer gas.
Another advantage of the process is that the sponge - iron particles can be cooled before leaving the kiln. This can be effected, for example, by passing a portion of the cool treated gaseous product into the lower part of the shaft kiln below the reaction zone and into which sponge iron particles ~all as they are produced so cooling these particles by heat exchanye and heating the gas stream. The cool gas naturally - gains heat as it travels up the kiln, heat being absorbed from the hot falling iron particles and the gas may be sufficiently hot by the time it reaches the reaction zone to ta~e part in the reduction reaction. The cool gaseous product of course contains substantially no carbon dioxide and water vapour and thus the falling sponge iron particles do not oxidise while they are being cooled. Furthermore, as a result of this heated gas passing into the reaction zone, the proportion of carbon dioxide and ~ater vapour in that zone will be decreased still further, so increasing the efficiency of the reduction reaction.
;
~3'~
It is also possible for the recyc:Led gaseous product which is heated to be mixed with the reducer gas being fed to the reaction zone before the latter actually enters that zone instead of the heated gaseous product being passed directly into the reaction zone. Thus the temperature of the reducer gas can be controlled by varying the quantity of heated gaseous product mixed with it and/or by mixing with it a separate cooling gas stream as indicated above. The reduction reaction between the iron oxide and the carbon monoxide and hydrogen is made up of a series of reactions. In these, iron oxide is converted into intermediate compounds in various degrees of reduction and the most highly reduced intermediate compound is ferrous oxide which takes part in an equilibrium reaction between, on the one side ferrous oxide, carbon monoxide and hydrogen and on the other side carbon dioxide, water vapour and iron. The introdùction with the reducer gas of small quantities of water vapour and carbon dioxide which are addi-tional to those formed by the reaction itself will clearly cause the reaction to favour the presence of ferrous oxide rather than iron, so tending to reduce the yield of iron. For this reason the guantity of carbon dioxide and water vapour over and above that produced in the reaction should be kept to the minimum, and since the treated gaseous reaction products contain substantially no carbon dioxide and water vapour the total amount of carbon dioxide and water vapour in the reaction zone will be lower than would be the case were the gas in that zone to consist solely of untreated reducer gas because that gas contains small amounts of carbon dioxide and water vapour The yield of~sponge iron is thus improved in a process according to the invention.
_ 5 _ ~ .
:
1~7~
As mentioned above the equilibrium reaction involving ferrous oxide is believed to be the last of the series and, since sponge iron particles are passing downwardly through the shaft kiln, the treated gaseous reaction products can conveni-ently be introduced into the lower region of the reaction zone below the point where the reducer gas enters. This i~ because the ferrous oxide intermediate compound will be present in that region and little carbon dioxide and water vapour will be present.
Thus the final conversion of ferrous oxide to sponge iron will be favoured.
The reducer gas containing carbon monoxide and hydro-gen can be produced catalytically by reforming natural gas and ; steam.
The invention also relates to an apparatus ~or pro-ducing sponge iron which comprises a reaction chamber for reacting the iron oxide with a reducer gas such as carbon monoxide and hydrogen, means for reducing the quantity of or substantially removing the oxidising part of the gaseous reaction products such as carbon dioxide and water vapour, and means for passing at least a portion of the so treated reaction products back into the reaction chamber. Preferably means are provided for heating the treated reaction products before they are passed into the reaction ~one.
The chamber for reacting the iron oxide can be a shaft kiln with the iron oxide particles added at the top and sponge iron particles removed from the base. The top and base of this kiln will therefore need a seal to prevent loss or escape of the hot gases. This seal can be provided by the build up of ~articles, either fresh particles at the top or sponge iron particles at the base, on a plate which extends ~al7~ ?~ , almost completely across the kiln. A reciprocable, ram-operated feeder can be provided to push partlcles from the base of the built-up pile to the edye of the plate where it does not quite extend completely across the kiln. Then the particles fall over this edge and either into or out of the reaction zone. The wall o~ the kiln may be provided with a reinforced striker plate near this edge of the support plate so that in its advanced position the rain operated feeder can crush :Lumps which are too large between itself and the striker plate.
The invention will now be illustrated, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a sectional elevation of a shaft kiln for carrying out the process of the invention;
Figure 2 is a detail from Figure l; and Figure 3 is a diagram showing how the kiln of Figure 1 can be utilised.
The shaft kiln 10 for producing sponge iron from iron ore comprises an outer shell 12 and an inner refractory lining 13. Towards the top, and at the lower end, of the kiln 10 are provided an upper discharge device 15 shown in greater detail in Figure 2 and an identical lower discharge device 17. The upper discharge device 16 controls the introduction of particulate iron ore into the reaction zone 18 and the lower control device 17 controls the discharge of sponge iron from the kiln.
Each control device 16, as shown in Figure 2, comprlses a ram 22 attached to a shaft 24 slidably located in sealing guide members 26. A casing 30 surrounds the projecting ends of the shaft 24 and forms a sealing enclosure to prevent the escape of any gases wh~ch manage to pass through the sealing guide members 26.
, ~(~7fl~
The refractory lining 14 of the kiln is cut away in the region of the discharge device 16 and the lower of the refractory material above the device 16 is covered with a striker plate 32. The upper end of the refractory material 14 below the discharge device 16, is provided with a plate 34 for protecting that part of the refractory material from damage caused by lumps of material discharged by the device.
The ram 22 is supported on a horizontal plate 36 and is capable of being moved axially of the shaft 24 by movement lQ of the shaft 24 to cause particles to be discharged by the device. Any large lumps are crushed between the striker plate 32 and the ram 22 and are thereby sufficiently reduced in size to enable them to be discharged.
Particles of iron ore are allowed to pile up on top ~f the upper discharge device 16 to form a seal and so prevent gases in the reaction zone 18 escaping up through the top of the kiln.
Reducer gas is produced by catalytically reforming natural gas which contains methane and steam in a reformer 40 (Figure 3). This gas is passed through a line 42 to a mixing chamber 44 and hence through a line 46 to the kiln 10.
The reducer gas enters the reaction zone 18 of the kiln through an annular manifold 48 and radial passages 50.
The gaseous reaction products leave the reaction zone through an exit 52 and pass through a line 54 to a condenser 56 where water vapour is removed. The treated gases then pass through a line 58 to a propoxtioning valve 100 controlled by a device 102. -~
One stream of gases is passed through a line 104 to a flare. A
~uantity of ~as is returned through a line 106 to fire the reformer 40.
~ 8 --.- . ~, ......... .
- : . - . .
, . . : . :
7~
The main gaseous stream then passes through a line 62 to a circulation blower 64 and through a line 63 to a carbon dioxide scrubber 60 where carbon dioxide is removed.
The gases continue through a line 66 to a proportioning valve 68 controlled by a device 70 and a stream of gases is separated-and passed to a heater 72. That stream of gases which is of course free o~ gases capable of oxidising sponge iron back to iron oxide is passed through a line 74 to an inlet 75 where the heated gas is introduced into the lower region of lQ the reaction chamber 18, below the reducer gas manifold 48.
Iron ore particles discharged by the upper discharge device 16 and flowing downwardly through the reaction zone 18 are generally in the form of ferrous oxide where they meet the heated gases passed through the inlet 75. Therefore, little carbon dioxide and water vapour is present and sponge iron is readily reduced.
Treated gaseous reaction products flow through a line 76 to a proportioning valve 78 controlled by a device 80 and a stream of treated gases is separated and passed through a line 82 to the inlet 84 immediately below the lower discharge device 85. These gases flowing through the inlet 84 and up the kiln, cool sponge iron particles flowing through a cooling ~one 38 of the kiln. By the time the cooling gases have travelled sufficiently far up the kiln to reach the reactlon zone 18 they are hot enough to take part in the reduction reaction in that zone.
The remaining gaseous reaction products are passed through a line 90 to a proportioning valve 92 controlled by a device 94 an~ a tempering gas stream is passed form that valve through a line 96 to the mixing device 44 so as to control the '~ .
_ g _ :
L r~
temperature of the reducer gas being fed to the reaction zone by mixing varying amounts of tempering gas with the reducer gas.
Sponge iron produced in the kiln is discharged by the lower discharge device 17 and passed through a series of valves 108.
It is of course possible in another embodiment of the invention to extend the line 74 carrying the heated gaseous reaction products, not directly to the reaction zone 18, but to the mixing device 44.
With such an arrangement the mixing of the tempering gas stream with the reducer gas may or may not be necessary.
; ' , ' ' ' . ~ ~ , :
, -
The process can be effected, for example, in a shaft kiln.
The method according to the invention has the advantage that the carbon monoxide and hydrogen reducer gas is utilised more efficiently. Furthermore, since the treated gaseous reaction products cGntain reduced quantities of, or substantially no, carbon dioxide and water vapour, their presence in the reaction zone tends to reduce the total quantity of carbon dioxide and water vapour in that zone as compared with the total quantity present where only reducer gas is introduced into the reaction zone. Therefore, the efficiency of the reduction reaction and consequently the yields of sponge iron will be improved.
The treated gaseous reaction products preferably contain substantially no water vapour and carbon dioxide and are preferably divided into two or more gas streams. One of these can be heated and passed back into the reaction zone, another may be used as a tempering stream for mixing with the main reducer gas stream being fed to the reaction zone to control the 'temperature of that stream, and yet another may be used to fire the reformer for producing the reducer gas .
'' ` ` ~
~7L~
although instead of this a stream of cooled gaseous reaction product before removal of the carbon dioxide and water vapour may be used. Any number of streams may be provided.
The separation of the treated gases into gas streams in this manner has the advantage that the temperature of the reducer gas being fed to the reaction zone can be very effect-ively controlled. This is important because, if the temperature of the reducer gas is too high, iron oxide particles will agglo-merate in the reaction zone. On the other hand if the tempera-ture is too low the efficiency of the reaction will be deleteri-ously affected. The optimum temperature is believed to be about 850 to 900C and this temperature can be malntained by varying the amount of tempering gas mixed with the reducer gas.
Another advantage of the process is that the sponge - iron particles can be cooled before leaving the kiln. This can be effected, for example, by passing a portion of the cool treated gaseous product into the lower part of the shaft kiln below the reaction zone and into which sponge iron particles ~all as they are produced so cooling these particles by heat exchanye and heating the gas stream. The cool gas naturally - gains heat as it travels up the kiln, heat being absorbed from the hot falling iron particles and the gas may be sufficiently hot by the time it reaches the reaction zone to ta~e part in the reduction reaction. The cool gaseous product of course contains substantially no carbon dioxide and water vapour and thus the falling sponge iron particles do not oxidise while they are being cooled. Furthermore, as a result of this heated gas passing into the reaction zone, the proportion of carbon dioxide and ~ater vapour in that zone will be decreased still further, so increasing the efficiency of the reduction reaction.
;
~3'~
It is also possible for the recyc:Led gaseous product which is heated to be mixed with the reducer gas being fed to the reaction zone before the latter actually enters that zone instead of the heated gaseous product being passed directly into the reaction zone. Thus the temperature of the reducer gas can be controlled by varying the quantity of heated gaseous product mixed with it and/or by mixing with it a separate cooling gas stream as indicated above. The reduction reaction between the iron oxide and the carbon monoxide and hydrogen is made up of a series of reactions. In these, iron oxide is converted into intermediate compounds in various degrees of reduction and the most highly reduced intermediate compound is ferrous oxide which takes part in an equilibrium reaction between, on the one side ferrous oxide, carbon monoxide and hydrogen and on the other side carbon dioxide, water vapour and iron. The introdùction with the reducer gas of small quantities of water vapour and carbon dioxide which are addi-tional to those formed by the reaction itself will clearly cause the reaction to favour the presence of ferrous oxide rather than iron, so tending to reduce the yield of iron. For this reason the guantity of carbon dioxide and water vapour over and above that produced in the reaction should be kept to the minimum, and since the treated gaseous reaction products contain substantially no carbon dioxide and water vapour the total amount of carbon dioxide and water vapour in the reaction zone will be lower than would be the case were the gas in that zone to consist solely of untreated reducer gas because that gas contains small amounts of carbon dioxide and water vapour The yield of~sponge iron is thus improved in a process according to the invention.
_ 5 _ ~ .
:
1~7~
As mentioned above the equilibrium reaction involving ferrous oxide is believed to be the last of the series and, since sponge iron particles are passing downwardly through the shaft kiln, the treated gaseous reaction products can conveni-ently be introduced into the lower region of the reaction zone below the point where the reducer gas enters. This i~ because the ferrous oxide intermediate compound will be present in that region and little carbon dioxide and water vapour will be present.
Thus the final conversion of ferrous oxide to sponge iron will be favoured.
The reducer gas containing carbon monoxide and hydro-gen can be produced catalytically by reforming natural gas and ; steam.
The invention also relates to an apparatus ~or pro-ducing sponge iron which comprises a reaction chamber for reacting the iron oxide with a reducer gas such as carbon monoxide and hydrogen, means for reducing the quantity of or substantially removing the oxidising part of the gaseous reaction products such as carbon dioxide and water vapour, and means for passing at least a portion of the so treated reaction products back into the reaction chamber. Preferably means are provided for heating the treated reaction products before they are passed into the reaction ~one.
The chamber for reacting the iron oxide can be a shaft kiln with the iron oxide particles added at the top and sponge iron particles removed from the base. The top and base of this kiln will therefore need a seal to prevent loss or escape of the hot gases. This seal can be provided by the build up of ~articles, either fresh particles at the top or sponge iron particles at the base, on a plate which extends ~al7~ ?~ , almost completely across the kiln. A reciprocable, ram-operated feeder can be provided to push partlcles from the base of the built-up pile to the edye of the plate where it does not quite extend completely across the kiln. Then the particles fall over this edge and either into or out of the reaction zone. The wall o~ the kiln may be provided with a reinforced striker plate near this edge of the support plate so that in its advanced position the rain operated feeder can crush :Lumps which are too large between itself and the striker plate.
The invention will now be illustrated, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a sectional elevation of a shaft kiln for carrying out the process of the invention;
Figure 2 is a detail from Figure l; and Figure 3 is a diagram showing how the kiln of Figure 1 can be utilised.
The shaft kiln 10 for producing sponge iron from iron ore comprises an outer shell 12 and an inner refractory lining 13. Towards the top, and at the lower end, of the kiln 10 are provided an upper discharge device 15 shown in greater detail in Figure 2 and an identical lower discharge device 17. The upper discharge device 16 controls the introduction of particulate iron ore into the reaction zone 18 and the lower control device 17 controls the discharge of sponge iron from the kiln.
Each control device 16, as shown in Figure 2, comprlses a ram 22 attached to a shaft 24 slidably located in sealing guide members 26. A casing 30 surrounds the projecting ends of the shaft 24 and forms a sealing enclosure to prevent the escape of any gases wh~ch manage to pass through the sealing guide members 26.
, ~(~7fl~
The refractory lining 14 of the kiln is cut away in the region of the discharge device 16 and the lower of the refractory material above the device 16 is covered with a striker plate 32. The upper end of the refractory material 14 below the discharge device 16, is provided with a plate 34 for protecting that part of the refractory material from damage caused by lumps of material discharged by the device.
The ram 22 is supported on a horizontal plate 36 and is capable of being moved axially of the shaft 24 by movement lQ of the shaft 24 to cause particles to be discharged by the device. Any large lumps are crushed between the striker plate 32 and the ram 22 and are thereby sufficiently reduced in size to enable them to be discharged.
Particles of iron ore are allowed to pile up on top ~f the upper discharge device 16 to form a seal and so prevent gases in the reaction zone 18 escaping up through the top of the kiln.
Reducer gas is produced by catalytically reforming natural gas which contains methane and steam in a reformer 40 (Figure 3). This gas is passed through a line 42 to a mixing chamber 44 and hence through a line 46 to the kiln 10.
The reducer gas enters the reaction zone 18 of the kiln through an annular manifold 48 and radial passages 50.
The gaseous reaction products leave the reaction zone through an exit 52 and pass through a line 54 to a condenser 56 where water vapour is removed. The treated gases then pass through a line 58 to a propoxtioning valve 100 controlled by a device 102. -~
One stream of gases is passed through a line 104 to a flare. A
~uantity of ~as is returned through a line 106 to fire the reformer 40.
~ 8 --.- . ~, ......... .
- : . - . .
, . . : . :
7~
The main gaseous stream then passes through a line 62 to a circulation blower 64 and through a line 63 to a carbon dioxide scrubber 60 where carbon dioxide is removed.
The gases continue through a line 66 to a proportioning valve 68 controlled by a device 70 and a stream of gases is separated-and passed to a heater 72. That stream of gases which is of course free o~ gases capable of oxidising sponge iron back to iron oxide is passed through a line 74 to an inlet 75 where the heated gas is introduced into the lower region of lQ the reaction chamber 18, below the reducer gas manifold 48.
Iron ore particles discharged by the upper discharge device 16 and flowing downwardly through the reaction zone 18 are generally in the form of ferrous oxide where they meet the heated gases passed through the inlet 75. Therefore, little carbon dioxide and water vapour is present and sponge iron is readily reduced.
Treated gaseous reaction products flow through a line 76 to a proportioning valve 78 controlled by a device 80 and a stream of treated gases is separated and passed through a line 82 to the inlet 84 immediately below the lower discharge device 85. These gases flowing through the inlet 84 and up the kiln, cool sponge iron particles flowing through a cooling ~one 38 of the kiln. By the time the cooling gases have travelled sufficiently far up the kiln to reach the reactlon zone 18 they are hot enough to take part in the reduction reaction in that zone.
The remaining gaseous reaction products are passed through a line 90 to a proportioning valve 92 controlled by a device 94 an~ a tempering gas stream is passed form that valve through a line 96 to the mixing device 44 so as to control the '~ .
_ g _ :
L r~
temperature of the reducer gas being fed to the reaction zone by mixing varying amounts of tempering gas with the reducer gas.
Sponge iron produced in the kiln is discharged by the lower discharge device 17 and passed through a series of valves 108.
It is of course possible in another embodiment of the invention to extend the line 74 carrying the heated gaseous reaction products, not directly to the reaction zone 18, but to the mixing device 44.
With such an arrangement the mixing of the tempering gas stream with the reducer gas may or may not be necessary.
; ' , ' ' ' . ~ ~ , :
, -
Claims (6)
1. A method of producing sponge iron in which an iron oxide is reduced with a reducer gas in a reaction zone to give a sponge iron product and a gaseous reaction product at least part of which is then treated to reduce the quantity of oxidising gas therein and at least a part of the thus treated gaseous reaction product is recycled to the reaction zone.
2. A method as claimed in Claim 1 in which the treated gaseous reaction product is heated before recycling to the reaction zone.
3. A method as claimed in Claim 2 in which the treated gaseous reaction product is heated by heat exchange with the sponge iron product.
4. A method as claimed in claim 1, 2 or 3 in which a part of the thus treated gaseous reaction product is mixed with fresh reducer gas and the resulting mixture fed to the reaction zone.
5. A method as claimed in claim 1, 2 or 3 in which the temperature of the reducer gas in the reaction zone is 850 to 900°C.
6. A method as claimed in claim 1, 2 or 3 in which the iron oxide passes through the reaction zone in counter-current flow with the reducer gas and recycled gaseous reaction product, the recycled gaseous reaction product being introduced into contact with the iron oxide reactant at a latter stage in its passage through the reaction zone than with the reducer gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA243,262A CA1074124A (en) | 1976-01-09 | 1976-01-09 | Sponge iron production process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA243,262A CA1074124A (en) | 1976-01-09 | 1976-01-09 | Sponge iron production process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1074124A true CA1074124A (en) | 1980-03-25 |
Family
ID=4104944
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA243,262A Expired CA1074124A (en) | 1976-01-09 | 1976-01-09 | Sponge iron production process |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1074124A (en) |
-
1976
- 1976-01-09 CA CA243,262A patent/CA1074124A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4054444A (en) | Method for controlling the carbon content of directly reduced iron | |
| US4046557A (en) | Method for producing metallic iron particles | |
| RU2087543C1 (en) | Method of processing iron-ore raw material (versions) | |
| US3749386A (en) | Method and means for reducing iron oxides in a gaseous reduction process | |
| MX2011003644A (en) | Process for production of direct reduced iron. | |
| US4253867A (en) | Method of using a methane-containing gas for reducing iron ore | |
| KR100195306B1 (en) | Shaft furnace for production of iron carbide | |
| KR850001212B1 (en) | Recovering non-volatile metals from dust containing metal oxides | |
| KR850001644B1 (en) | Direct reduction of iron using coke oven gas | |
| US3748120A (en) | Method of and apparatus for reducing iron oxide to metallic iron | |
| EP0459810A2 (en) | Method and apparatus for the production of hot direct reduced iron | |
| CN107881280A (en) | It is a kind of to reduce and cool down the system and method for metallized pellet | |
| US3816101A (en) | Method for reducing iron oxides in a gaseous reduction process | |
| JPS5818963B2 (en) | Method for reducing granular iron ore to sponge iron particles | |
| US4556417A (en) | Process for the direct reduction of iron ores | |
| US4752329A (en) | Apparatus and method for increasing carbon content of hot directly reduced iron | |
| US4702766A (en) | Method of increasing carbon content of direct reduced iron and apparatus | |
| JPS5847449B2 (en) | direct iron making method | |
| CA1228482A (en) | Reduction of metal compounds | |
| US4439233A (en) | Direct reduction of iron | |
| CA1075913A (en) | Method and apparatus for producing metallic iron particles | |
| CA1074124A (en) | Sponge iron production process | |
| US6565623B2 (en) | Method and apparatus for curing self-reducing agglomerates | |
| NO137647B (en) | PROCEDURES AND EQUIPMENT FOR DIRECT REDUCTION OF IRON ORE | |
| US3799521A (en) | Method and apparatus for the gaseous reduction of iron ore to sponge iron |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |