JPS6137329B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention is a method for directly producing sponge iron particles and liquid pig iron from lumpy iron ore as stated in the preamble of claim 1, wherein the iron ore is directly reduced. The sponge iron particles, which are reduced to sponge iron particles by hot reducing gas in a loosely packed state in the apparatus and discharged from the direct reduction apparatus, are fed to the melter-gasifier, in which the sponge iron is converted into sponge iron particles. The necessary heat to melt and the reducing gas is produced from the coal introduced into the melter-gasifier and the oxygen-containing gas which is blown into the melter-gasifier, at least a portion of the reducing gas being specified for the reduction operation. The present invention relates to a manufacturing method in which the filtrate is cooled to a temperature at which the filtrate is cooled and then flowed into the reduction zone of a direct reduction device. The present invention also provides a direct reduction device disposed above the melting and gasifying furnace as stated in the preamble of claim 25, which has a discharge means for hot sponge iron at its lower end. an installation for producing sponge iron particles and liquid pig iron from lump iron ore, comprising a direct reduction device, the outlet opening of the discharge means being in communication with the melting and gasifying furnace via at least one connecting conduit. , and the equipment as stated in the preambles of claims 32 and 36. The term lumpy iron ore is used to describe iron ore in the form of lumps or flakes, including pellets.

PRIOR ART A method and installation of this type is described in West German patent no.
It is disclosed in the specification of No. 3034539. In the known process, the operation of melting the sponge iron produces about 40% more reducing gas than is required to produce the same amount of sponge iron. In order to operate the equipment economically, it is necessary to consume excess gas. This means that equipment must be connected to other equipment. However, the coupling of multiple facilities results in a reduction in overall facility availability and survivability, and results in worse economics.

Depending on the iron ore used, larger pieces of sponge iron are already moving at a high velocity when they are discharged from the reduction device and proceed into the settling chamber, where the downward movement speed becomes even faster; The coal passes rapidly through the fluidized bed in the melter-gasifier. Due to the shorter residence time of such sponge iron in the coal fluidized bed, the temperature rise of the sponge iron is correspondingly smaller. In contrast, small particle sponge iron has a longer residence time in the fluidized bed, is heated to higher temperatures, and dissolves more rapidly.

OBJECT OF THE INVENTION The object of the invention is to provide a process of the kind mentioned in the opening part of the present specification, which works economically without excess gas and is capable of increasing the specific output of a melter-gasifier, and The objective is to provide a method by which driving style can be improved. Another object of the invention is to
The objective is to provide equipment for carrying out this method.

Structure of the Invention As stated in the characteristic part of claim 1, the method according to the present invention separates sponge iron particles discharged from a direct reduction device into fine particles and coarse particles, and then separates the fine particles into coarse particles. A method for producing sponge iron particles and liquid pig iron directly from lump iron ore, characterized in that only iron ore is introduced into a melting and gasifying furnace, and an advantageous embodiment of this method is defined in claim 2.
As stated in paragraphs 24 to 24. In the equipment according to the present invention, as described in the characteristic part of claim 25, the coarse separator 7 is incorporated in the connecting conduit between the direct reduction device 2 and the melting and gasification furnace 1, Outlet opening 8 for fine particles in this separator
is in communication with the melting and gasifier, and the outlet opening 11 for the coarse fraction of this separator is connected to another melting device or means 1 for hot compaction, passivation or cooling.
3, and advantageous embodiments of this equipment are set out in claims 26 to 38. It is being

In the method according to the invention, the entire amount of sponge iron particles produced in the direct reduction device is not fed to the melting gasifier, but is part of it, so that when these particles are dissolved, a smaller amount of gas is produced, thereby avoiding an excess of reducing gas. The portion of the sponge iron particles supplied to the gasifier is selected as long as the upper limit of the coarse diameter is limited. This ensures that larger pieces of sponge iron do not pass through the coal fluidized bed without being sufficiently heated, and that the melting zone of the melting gasifier uses increased energy to melt the material that can be melted. ensure that they are not harmed by the build-up of The coarse particles that are separated on the way from the reduction equipment to the melting and gasifying furnace can be fed in a hot state to a melting vessel such as an arc furnace, but they can be hot-compressed or unprocessed to be used as charging material for the melting furnace. Mobilization or cooling can also be used.

Since the method according to the invention allows only the fine particles to be melted in the melter-gasifier, difficulties will be encountered if the melter-gasifier is fed with unrefined sulfur-rich coal. More specifically, since the surface area of fine sponge iron particles is larger relative to their weight, the fine grain fraction has more sulfur in the reducing gas than the coarse grain fraction, and is therefore less likely to be produced in the melter-gasifier. The liquid pig iron produced has an undesirably high sulfur content. In this case, additional measures are necessary to reduce the sulfur content, and the additional measures integrated into the method according to the invention include the following steps, which may be combined alone.

1. Supplying a desulfurization agent to the melting and gasifying furnace; 2. Mixing the proportion of crude gas produced by coal gasification in the reducing gas with a portion of the waste gas from the direct reduction device after CO ₂ absorption treatment and 3. Reducing the proportion of fines melted in the melt-gasifier to save on the heat required for melting, which would have to be produced by burning the coal.

Regarding the step in item 3 above, it is also possible to feed part of the waste gas from the direct reduction unit to the melting gasifier as an oxygen carrier, and part of the coal to be used as the oxygen carrier for carbon dioxide and carbon dioxide in the waste gas. It is also possible to gasify by endothermic reaction with water vapor.

When carrying out the steps described above, a reduction in the sulfur content of the fine sponge iron particles will lead to a significant reduction in the sulfur content of the coarse sponge iron particles used elsewhere, so that the sponge iron particles are It is no longer necessary to take special steps to remove the sulfur from it when it is dissolved.

If the separation of the sponge iron particles into fine and coarse fractions is carried out immediately after discharge from the direct reduction device, the sponge iron particles will leave the direct reduction device at a temperature between 700 and 900°; Coarse grain separators must be designed for these temperatures. This poses a challenge in some sorting or sorting equipment, particularly those using screens. In this case, it is preferable that the sorting operation of the sponge iron particles is carried out only after the cooling operation. It is preferred to use the cleaned and treated waste gas from the direct reduction unit as a coolant to cool the sponge iron particles before they are separated. In this case,
It is desirable to take steps to ensure that the coolant cannot pass directly to the reduction device via the cancellous iron particle transport conduit.

Separated sponge iron particles are cooled from the reduction device,
It is preferably cooled by the cleaned and treated waste gas, which after heat exchange with the sponge iron particles is combined with the hot reducing gas stream from the melt-gasifier to the reduction unit for temperature control purposes. mixed. This type of treatment results in an economical use of the waste gas from the reduction equipment.

The operation of separating the coarse fraction of sponge iron particles increases the relative proportion of fine material in the sponge iron fed to the melter-gasifier and thus also reduces the amount of fine material that will be discharged from the gasifier. Increase. According to the development of the invention, therefore, the location from which the sponge iron particles are discharged in the melter-gasifier is shifted downward from the top or cover of the vessel and closer to the upper boundary of the coal fluidized bed. This is preferably accomplished by a gravity feed pipe extending from above into the melting gasifier to near the upper boundary of the fluidized coal bed formed within the gasifier.
In this way, the introduction of sponge iron particles can also be achieved with a slow vertical velocity component by suitably changing the direction of the sponge iron particle flow. This change in direction can be achieved by providing projections arranged in a cascade arrangement in the lower region of the gravity feed tube or by providing at least one diagonal plate below the gravity feed tube;
It is preferable that this jiyama board is in the form of a truncated conical member having a shape similar to a Chinese hat.

In order to provide a controlled supply of sponge iron particles into the melting gasifier, evacuation means are advantageously provided between the coarse separator and the melting gasifier, and one or more gravity feed pipes are provided with sponge iron particles. Iron particles are supplied in a controlled amount by the evacuation means. In this way,
It is also possible to increase the flow resistance for the reducing gas rising via the gravity feed pipe and avoid overheating and sintering of the sponge iron particles in the area of the coarse separator and in the lower part of the reduction device. can.

EMBODIMENTS OF THE INVENTION The invention will now be explained in more detail by means of two embodiment examples associated with four drawings.

The apparatus for the direct production of liquid pig iron from lump iron ore, diagrammatically shown in FIG.
No. 0010627 (i.e., the corresponding JP-A-55-94408)
Melting and gasifying furnace 1 of the type described in
Contains. Shaft furnace 2 is installed above gasifier 1.
is arranged, and in its operating mode this shaft furnace corresponds to the upper part of a blast furnace or a direct reduction shaft furnace. The latter furnace is described in principle, for example, in DE-OS 2935707. The direct reduction shaft furnace is fed from above, as indicated by the arrow 3, with lump iron ore, which moves downwards in the shaft furnace in a loosely packed manner and passes through the central gas inlet 4.
It is reduced to sponge iron by hot reducing gas blown in at a temperature of about 750 to 900°C. The consumed or used reducing gas (hereinafter referred to as waste gas) leaves the shaft furnace 2 via the upper gas outlet 5.

Hot sponge iron produced by reduction of lump iron ore is directly removed from the bottom of the reduction shaft furnace 2 by about 750 to
It is discharged at a temperature of 850° C. and passes via pipe 6 into a coarse separator 7. The separator 7 is of the form described in more detail below in connection with FIG. Alternatively, the separator comprises a screen capable of being subjected to a heat load and having a mesh size of, for example, 20 mm, preferably 12 mm, by means of which the sponge iron particles having a size of 12 mm or more are retained. . Sponge iron particles are separated into fine particles and coarse particles. The fine portion of the sponge iron particles leaves the coarse separator 7 via the first outlet opening 8 and passes via the pipe 9 into the discharge means 10 . This ejection means includes, for example, a screw or reamer member. The coarse portion of the sponge iron particles leaves the coarse separator 7 through the second outlet aperture 11 and passes via the tube 12 to the cooling device 13 . In this cooling device, the particles are cooled to ambient temperature so that they can be transported to the point where they are to be processed without serious risk of re-oxidation. The discharge of cooled sponge iron particles from the cooling device 13 is indicated by the reference numeral 14.

The discharge means 10 has at its lower end an outlet aperture 16 for the sponge iron particles, which communicates with the interior of the melter-gasifier 1 via at least one gravity feed pipe 17 . The sponge iron particles are metered out through the outlet aperture 16. In this way, the charge material required to load the melting gasifier is supplied to the gravity feed pipe 1.
7 in the amount required for the melting process in the gasifier, either continuously or intermittently. The coal necessary to form and maintain a coal fluidized bed is
5 directly to the melting and gasifying furnace 1.

As stated in European Patent Publication No. 0010627, a melting gasifier may be divided into three parts depending on its operating state. These parts are a lower part 18 with pig iron and slag, an intermediate part 19 for the coal fluidized bed and an enlarged upper part 20 which serves as a settling or stabilizing chamber. In accordance with the development of the invention, the feeding of the sponge iron particles to the gasifier 1 does not take place at the upper boundary of the pacification chamber 20, but in the vicinity of the upper boundary of the coal fluidized bed 19 within the pacification chamber 20. It is done. In the present case, this is accomplished by a gravity feed tube 17 extending deep into the chamber 20. In that way it is practicable to reduce the amount of granular material discharged from the melter-gasifier together with the gas, which in the process according to the invention is reduced by the total amount of sponge iron introduced into the melter-gasifier. Works on a special part. The best depth to which tube 17 extends into the gasifier can be easily determined by experiment. Preferably, the gravity feed pipe 17 terminates just above the upper boundary of the coal fluidized bed.

The use of one or more gravity feed pipes 17 significantly reduces the vertical velocity component of the descending material, thereby increasing the residence time of the sponge iron within the coal fluidized bed. Reduction of the vertical velocity component may be achieved by a redirecting action of the tube 17 at its lower end or by the provision of a baffle plate. The high heat load on the gravity feed pipes extending into the interior of the melter-gasifier makes it desirable for the pipes to be cooled. A possible form of such a gravity feed tube is described in connection with FIG.

FIG. 1 also shows grooves or troughs 21 and 22 for removing pig iron and slag.
A nozzle or tuyere 23 for blowing oxygen-containing gas is shown schematically.

The reducing gas produced in the melting gasifier 1 leaves the gasifier 1 through its outlet 24 at a temperature of about 1200°C. This gas flows from there via the reducing gas conduit 25 directly to the gas inlet of the reducing unit 2. The reducing gas introduced into the direct reduction unit 2 is 900
The cooling gas supplied via conduit 27 is mixed at reference numeral 26 with the hot reducing gas stream flowing upwardly through conduit 25 for temperature control, so that the temperature does not exceed 0.degree. The cooling gas is cleaned and cooled with the waste gas from the direct reduction unit 2 in the waste gas scrubber 28 and the CO ₂ in the gas is removed.
It is the recycled waste gas after the proportion has been reduced in the CO ₂ absorption tower 29. Although the waste gas after such treatment is mixed with hot reducing gas from the melting gasifier for temperature control, in the embodiment described herein the treated waste gas is mixed with coarse fraction. The water is passed through a cooler 13 which is in a direct heat exchange relationship with the sponge iron particles. The temperature of the waste gas treated in this heat exchange operation rises to 500°C. The waste gas is then mixed via conduit 27 with the hot reducing gas stream in conduit 25 at 26, thereby reducing the temperature of the reducing gas stream below 900°C.
If sponge iron rather than pig iron is to be produced in the facility, a portion of the treated waste gas may be preheated in a separate recuperator 40 connected in parallel with the cooler 13. A desired active pipe gas temperature can be set. The heated gas used is waste gas that is not treated downstream of the waste gas scrubber 28;
The amount of gas used for this purpose depends on the amount of heat required. Such an arrangement avoids enriching the recycle gas with inert components such as _N2 .

Reference numeral 30 in FIG. 1 indicates a compressor, which is placed upstream of the CO ₂ absorption column 29 to create the necessary pressure. In order to produce sponge iron with a low sulfur content, the gas from the melter-gasifier 1 must be desulfurized in a hot gas desulfurizer 32 . For this purpose, cold gas can be added to the gas from the gasifier 1 to make the gas temperature suitable for the desulphurization operation.

To avoid sintering, remove tube 1 from the melting gasifier
The amount of hot gas flowing upward through 7, 9 and 6 must be kept low. This can be achieved by a high flow resistance in the area of the evacuation means 10, the gravity feed pipe 9 and the coarse separator 7, if the evacuation is controlled such that the pipe 9 is always at least partially filled with material. . In this way, the resistance in the bypass path relative to the reducing gas conduit 25 is maintained at such a high level that there is no harmful flow of gas through this bypass path.

FIG. 2 is a partial cross-sectional view of a gravity feed pipe extending into the melter-gasifier. Due to the high temperatures inside the melter-gasifier, the tubes 17 are equipped with liquid cooling means. For this purpose, three metal tubes 31, 32 and 33 are arranged concentrically with respect to each other as shown in FIG. 2 to form a conduit for passing a cooling fluid, for example water. The cooling system is covered on all sides with a layer of refractory material indicated at 34.

The illustrated gravity feed pipe 17 includes means for imparting a change in the flow direction of the sponge iron particles flowing down the pipe, thereby reducing the vertical velocity of the particles into the coal fluidized bed. The reduced velocity at which the particles travel increases the residence time of the particles. For that purpose, a projection 3 is provided in the lower area of the gravity feed pipe 17.
5, the protrusions are arranged in a cascade formation and material is deposited on these protrusions to serve as a means of providing protection from wear.
Instead of or in addition to such projections,
It is also possible to provide a bulge plate 36 at the bottom outlet of the tube, which plate is preferably in the form of a truncated cone (resembling a Chinese hat). The sponge iron particles moving downwards are deflected by the protrusions 35 in the tube and wind their way, and the speed of movement of the particles in the tube is reduced by the protrusions, and the baffle plate 36 keeps the particles almost horizontally, thereby significantly reducing the vertical velocity component of the particles. Reference number 37 in FIG. 2 indicates the top of the melting and gasifying furnace.

The coarse grain separator 7 shown schematically in FIG. 3 is in the form of an inclined gravity feed channel or chute 38 and is provided with at least one connecting means or portion 39 branching downwardly from the channel 38. There is. In the same way as shown in FIG. 1, the pipe for feeding the sponge iron particles discharged from the direct reduction shaft furnace to the separator 7 is indicated by reference numeral 6, and the reference numeral 8 is for the fines fraction. The first outlet aperture is indicated and the reference numeral 11 indicates the second outlet aperture for the coarse fraction.

As the unrestrained or bulk material passes from above into the coarse separator 7, as it passes through the separator 7, the components form a mixture in such a way that the fine particles sink to the bottom and the coarse particles collect on top. separated from nature. Appropriate control of the flow of the sponge iron particles constituting the fines fraction from the first outlet aperture 8 produces the flow regime shown schematically in FIG. Gravity supply pipe 3
8 to the second discharge aperture 12;
It is discharged through the opening 12. The flow of fine sponge iron particles from the separator 7 through the connecting portion 39 is caused by the first
If controlled by a discharge means 10 connected to the coarse separator 7 by a tube as shown in the figure, then the flow resistance for the rising gas from the melter-gasifier is compared as necessary. can be maintained at a high level.

In the schematic diagram of the installation of the second embodiment as shown in FIG. 4, the same parts in the installation as shown in FIG. 1 are designated by the same references.

A direct reduction device in the form of a direct reduction shaft furnace 2 has at its top a charging means 3 of lumpy iron ore and the used or spent reducing gas (waste gas).
and is provided at its bottom with a gas inlet 4 for hot reducing gas and controllable evacuation means 41 for the sponge iron particles produced by direct reduction from iron ore. The melting gasifier 1 substantially corresponds to the gasifier of the first embodiment. However, in a second embodiment, the top or cover of the upper section 20, which serves as the pacification or stabilization chamber, has a chamber called the gasifier top section 42 and in communication with the pacification chamber 20. The top part 42 of the gasifier has a gas outlet 43 for the reducing gas (crude gas) produced in the melting gasifier,
It has a gas inlet 44 for the burned and treated waste gas from the direct reduction shaft furnace and an inlet 45 for the desulfurization agent. A coal supply pipe 15 and a immersion pipe 17 for introduction of fine particles pass through the top of the melting and gasifying furnace.

An outlet 21 for liquid pig iron and an outlet 22 for liquid slag are arranged in the lower part of the melting and gasifier, and above the slag level at least one tuyere or at least one for blowing gas and solid material for fines. A suction pipe or burner 23a is arranged.

A discharge means 41 is provided below the direct reduction shaft furnace 2.
A cooling device 13a is arranged for the hot sponge iron particles discharged through. The intake aperture 46 of the cooling device 13a for hot sponge iron particles communicates via the gravity feed conduit 6 with the discharge means 41. Connected to the gravity feed conduit 6 are level measuring means 47 for controlling the evacuation means 41 .

In its upper region, the cooling device 13a has inlet openings 46 for hot sponge iron particles as well as an outlet 4 for cooling gas.
8 and in its lower region an inlet 4 for the cooling gas in addition to an outlet aperture 14 for the cooled sponge iron particles.
It has 9. In the embodiment described in connection with FIG. 1, the cooling effect takes place in a countercurrent manner and with direct heat exchange in relation to the sponge iron particles descending in the cooling device. Since the cooling device 13a is not supplied with only the coarse portion of the sponge iron particles as in the embodiment shown in FIG. 1, the amount of fine particles discharged therefrom into the upper region of the cooling device is minimized. It is preferable to include a sedation chamber for this purpose. This is done, for example, by a gravity feed tube 6 extending a defined length into the cooling device so that a calming chamber is formed above the conical surface of the material inside the cooling device.

Classifying or sorting means 7a, arranged below the cooling device and connected by a gravity feed pipe 50 to the outlet aperture 14 of the cooling device, are in the form of screen stations and contain fine and coarse portions of sponge iron particles. Perform separation into minutes. The outlet aperture 8 for the fines fraction is connected by a conduit 9 to a fines container 10 which is arranged above the melting gasifier and has an outlet aperture 16 communicating with a dip tube 17. . Alternatively or in addition to
It is also possible to connect to a pipe 15 for introducing coal into the melter-gasifier. If the sorting means 7a cannot be arranged above the melter-gasifier and the conduit 9 cannot be arranged in the form of a gravity feed conduit due to lack of available space, suitable conveyor means for conveying the fines can be provided. It will be prepared for the conduit. If the classification operation by the sorting means 7a is carried out so that the fine particles contain only the part with a particle size of 3 mm or less, at least a part of the fine particles will be transferred to the melting furnace via the nozzle or tuyere 23 or 23a, respectively. It may be preferable to blow it inward. A suitable conduit will then be provided in the nozzle or tuyere.

A conduit 12 connected to the outlet aperture 11 of the sorting means 7a for the coarse fraction separated from the process can be used to separate the coarse fraction from a separate melting device or compaction or passivation means or as shown in FIG. The treated waste gas will be sent to a cooling device 13 where it will be supplied as a coolant.

As in the case of the embodiment described in connection with FIG. The gas outlet 54 of the column ₂₉ is connected via conduits 55 and 56 to the cooling gas inlet 49 of the cooling device 13a. In addition, as in the first embodiment, in order to mix the treated waste gas heated in the cooling device 13a with the reducing gas stream which flows via the conduit 25 to the gas outlet 4 of the direct reduction shaft furnace 2, cooling device 13
The installation includes a conduit 27 from the gas outlet 48 of a to the reducing gas conduit 25. This arrangement not only allows temperature control of the reducing gas fed to the direct reduction shaft furnace 2, but also allows the consumption of coal and oxygen in the melter-gasifier to be reduced by approximately half. This also reduces the amount of sulfur provided by the coal and the sulfur content in the reducing gas by almost half.

The installation shown in FIG. 4 includes the following additional equipment and connecting conduits to the installation shown in FIG.

a cooling gas circuit 5 including a conduit 56 and having a cooling gas scrubber 58 and a compressor 30a;
7 is associated with the cooling device 13a. This arrangement takes into account that the cooling operation in the cooling system requires a larger amount of cooling gas than the amount of treated waste gas supplied via conduit 55.

Cooling device gas outlet 48 or cooling gas circuit 57
From the conduit 27 connected to the gasifier, a conduit 59 branches off to an inlet 44 of the gasifier top section 42 . A connecting conduit 60 connected to the gas outlet 54 of the CO ₂ absorption tower 29 communicates with the conduit 59 . The treated waste gas can be fed to the gasifier top section 42 via conduit 59 at different temperatures so that its temperature can be adjusted to the optimum temperature for the hot gas desulfurization operation.

The outlet 43 for the reducing gas produced in the melting gasifier 1 in the gasifier top part 42 is connected via a conduit 61 to a cyclone 62 .
The gas outlet 63 of is connected directly to the reducing gas conduit 25 leading to the reducing device. Instead of a cyclone, a series of cyclones formed by connecting several cyclones together can be used. The separate solid material outlet opening 64 communicates via a conduit 65 with a conduit 66, which is connected via the compressor 30 to the gas outlet of the waste gas scrubber 28. Conduit 66 conveys a portion of the waste gas leaving waste gas scrubber 28 as oxygen-containing gas to burner or blowing pipe 23a, which gas also serves as a carrier gas for the solid material separated in cyclone 62. Oxygen is passed through the conduit 67 to the burner 23a or the tuyere 23.
can be supplied to The branch pipe 68 is a conduit 52 connected to the gas outlet 51 of the waste gas scrubber 28.
It extends from the steam generator 69 to the steam generator 69. Therefore, a part of the untreated waste gas is transferred to the CO ₂ gas absorption tower 29.
used as a heating gas to create the steam needed in

In addition to the need to avoid excessive amounts of reducing gas produced in the melting gasifier 1, when carrying out the process in the installation shown in Figure 4, it is important to note that the energy carrier used in the process is coal with a high sulfur content. If it is,
Taking into account in a special economical manner the sulfur content of the pig iron being melted in the gasifier and the need to keep the sulfur content of the coarse sponge iron particles separated from the process at a low level. . For that purpose,
Means for reducing the amount of energy required to dissolve fines in a melting gasifier and waste gas from a direct reduction device, partially untreated and partially after a CO ₂ removal operation and directly reduced Means are provided for supplying the gas to the process after direct heat exchange in the cooling device for the sponge iron discharged from the device.

The amount of energy required to create the heat of dissolution, which is created by burning coal, is the amount of fine particles compared to the coarse particles in the classification, that is, the operation of separating sponge iron particles in the sorting means 7a. In other words, by reducing the proportion
The fine particle fraction fed into the melting gasifier 1 is reduced by reducing the particle size to 5 mm, preferably 3 mm or less. Due to the longer residence time in the fluidized bed of the melting gasifier, these particles are dissolved with a considerably smaller amount of energy, in other words with a lower amount of coal, and therefore with a lower amount of sulfur. It is also possible to use a portion of the untreated waste gas supplied by the waste gas scrubber 28 and containing carbon dioxide and water vapor for the gasification of coal. In the embodiment shown in FIG.
to one or more burners or blow tubes 23a. Using waste gas as a carrier gas, the effluent from cyclone 62, ie, the desulfurization agent and coal particles separated from the reducing gas, is recycled to the melter-gasifier. In order to protect the injection openings from slugging or slag erosion, the burner 23a is supplied with oxygen or air as combustion agent via conduit 67 and combusts part of the waste gas or waste gas-dust mixture. conduit 66
The amount of waste gas supplied via the 805
The temperature should be adjusted to 1250°C to 1250°C, preferably 1100°C. It will be appreciated that the use of waste gas as an oxygen carrier for carrying out gasification operations can reduce oxygen consumption per ton of product, thereby increasing the economics of the process.

Coal saving and reduction of the sulfur content in the reducing gas and in the sponge iron will be achieved by the treated waste gas in the CO ₂ absorption tower being mixed with the reducing gas. In the process carried out in the installation shown in FIG. 4, this means that a portion of the waste gas treated in the CO ₂ absorption tower 29 is passed through the cooling device 13a via conduits 55 and 56 to the hot sponge iron. Heating occurs in direct contact with the particles, a portion of which is passed into reducing gas conduit 25 and another portion is passed via conduit 59 to gasifier top section 42 . Another portion of the treated waste gas supplied by the CO ₂ absorber 29 is sent directly to the gasifier top section 42 via conduit 60 and a portion of conduit 59. The amount of treated waste gas mixed with the reducing gas makes it possible to reduce the amount of sulfur introduced by the coal and the sulfur content in the reducing gas by about half due to the consumption of coal and oxygen.

The treated waste gas fed to the top section of the gasifier via conduit 59 also allows temperature control, where the temperature in conduit 59 is adjusted to the feed rate via conduit 27 and via conduit 60. It can be determined by the ratio between the supply amount and the supply amount. In order to further reduce the sulfur content in the reducing gas, temperature regulation in the gasifier top part is particularly essential when the desulfurization agent is fed into the gasifier top part or into the exhaust gas conduit 61. The optimum temperature for hot gas desulfurization is approximately 900℃
It is. In the method described above, a desulfurization agent such as finely divided calcium hydroxide is supplied to the gasifier top section 42 via an opening 45 and the optimum temperature for the desulfurization operation of the hot gas is set at the gas inlet 44. regulated by treated waste gas blown through. Desulfurization of the reducing gas takes place substantially within the gasifier top section and within the exhaust gas conduit 61. The depleted desulfurization agent and the undepleted desulfurization agent are separated in cyclone 62 and recycled via conduit 65 to the melter-gasifier.

The steps described above reduce the sulfur content of the sponge iron particles to such an extent that the separated coarse fraction can be processed in steelmaking without further sulfur removal operations, even when using sulfur-rich coals. becomes possible. The fine fraction, which has a significantly higher sulfur content than the coarse fraction for the reasons mentioned above (as fine sponge iron particles have a larger area relative to their weight, such particles retain more sulfur), is more susceptible to dissolved gases. It is at least partially desulfurized by the desulfurization agent supplied to the oxidizer and is separated from the bond by the slag.

[Brief explanation of the drawing]

1 is a schematic diagram of a first embodiment of the method and installation according to the invention, FIG. 2 is a longitudinal section through a gravity feed pipe with liquid cooling, and FIG. 3 is a schematic diagram of a coarse separator. and FIG. 4 is a schematic diagram of a second embodiment of the method and equipment according to the invention. 1... Melting gasification furnace, 2... Direct reduction shaft furnace, 7... Coarse separator, 10... Discharge means,
13...Cooling device, 17...Gravity supply pipe, 28...
...Waste gas scrubber, 29... _CO2 absorption tower, 30
...Compressor, 62...Cyclone.

Claims (1)

[Claims] 1. A method for directly producing sponge iron particles and liquid pig iron from lumpy iron ore, wherein the iron ore is reduced to sponge iron particles by hot reducing gas in a loosely packed state in a direct reduction device. and the sponge iron particles discharged from the direct reduction device are fed to a melting and gasifying furnace, in which the necessary heat and reducing gas for melting the sponge iron are introduced into the melting and gasifying furnace. and an oxygen-containing gas which is blown into the melter-gasifier, and after at least a portion of the reducing gas has been cooled to a temperature defined for the reduction operation, In the production method, the sponge iron particles discharged from the direct reduction device are separated into fine particles and coarse particles, and only the fine particles are introduced into the melting and gasifying furnace. A method for directly producing sponge iron particles and liquid pig iron from lumpy iron ore. 2. The method according to claim 1, wherein the fine particle fraction includes particles with a size of 20 mm or less. 3. The method according to claim 2, wherein the fine particle fraction includes particles having a size of 12 mm or less. 4 The upper limit of the particle size of the fine particles is such that the amount of reducing gas created when the sponge iron particles are melted in the melting and gasifier is necessary for the process of reducing iron ore in the direct reduction device. 2. A method according to claim 1, characterized in that the amount is selected to approximately correspond to the amount. 5. The fine sponge iron particles are introduced with a retarded vertical velocity component near the upper boundary of the fluidized bed formed in the melting and gasifier. The method described in any one of paragraphs to paragraphs 4 to 4. 6. A method according to claim 5, characterized in that the sponge iron particles are fed through at least one tube. 7. The separation between the fine particles and the coarse part is selected such that the average sulfur content of the fine part corresponds to at least five times the average sulfur content of the coarse part. A method according to any one of claims 1 to 6. 8. Process according to claim 7, characterized in that the average sulfur content of the fine fraction corresponds to at least 10 times the average sulfur content of the coarse fraction. 9. The method according to claim 7 or 8, wherein the particle group of the fine particles contains particles with a size of 5 mm or less. 10. The method according to claim 9, wherein the particle group of the fine particles includes particles having a size of 3 mm or less. 11. The method according to any one of claims 1 to 10, characterized in that a desulfurizing agent is added to the reducing gas produced in the melting and gasifying furnace. 12. Process according to claim 11, characterized in that the desulfurization agent is injected into the top part of the melting gasifier and/or into the exhaust gas conduit for the reducing gas. 13. The waste gas from the direct reduction device is cleaned and cooled by a waste gas scrubber, and after being treated for _CO2 removal, a part of it is mixed with the reducing gas produced by the melting gasifier. A method according to any one of claims 1 to 12. 14. A portion of the cleaned and treated waste gas is heated in direct heat exchange relationship by sponge iron particles discharged from the direct reduction device before being mixed with the reducing gas. The method according to claim 13. 15. A method according to claim 13 or 14, characterized in that the treated waste gas is blown into the top part of the melter-gasifier. 16. Any one of claims 13 to 15, characterized in that the treated waste gas is blown into the reducing gas conduit from the melting gasifier to the direct reduction device. The method described in. 17 Direct heat exchange of the cleaned and treated waste gas with the sponge iron particles takes place in a cooling device into which the hot sponge iron particles discharged from the direct reduction device are introduced via a gravity feed pipe. 17. A method according to any one of claims 14 to 16, characterized in that the method is carried out as: 18. A method according to claim 17, characterized in that, after direct heat exchange with the treated waste gas, the sponge iron particles are separated into the fine fraction and the coarse fraction. 19. Claims 1 to 18, characterized in that the coarse sponge iron particles are cooled by the cooled, washed and treated waste gas from the direct reduction device. Any method described. 20 A patent characterized in that the waste gas from the direct reduction device is cleaned and cooled in a waste gas scrubber, and then a part of it is supplied to the melting and gasifying furnace as an oxygen carrier or a gasifying agent. A method according to any one of claims 1 to 19. 21. A method according to claim 20, characterized in that a fluidized bed is formed in the melting gasifier and the waste gas is blown into this fluidized bed. 22 The reducing gas produced in the melting gasifier is dedusted in at least one cyclone before being fed to the direct reduction unit, and the cyclone separates and removes the solid particles discharged therefrom. 22. A method according to any of claims 1 to 21, characterized in that at least a portion is recycled to the melter-gasifier. 23. A method according to claim 21 or 22, characterized in that cyclone exhaust is blown into the melting gasifier using the waste gas as a carrier gas. 24. Claim 23, characterized in that the cyclone discharge is also blown into the melting gasifier via at least one blowing pipe with the waste gas after mixing with oxygen or air. The method described in section. 25 A direct reduction device located above the melting and gasifier, having at its lower end a discharge means for the hot sponge iron, the outlet opening of which is connected via at least one connecting conduit. In the equipment for producing sponge iron particles and liquid pig iron from lumpy iron ore, the coarse separator 7 is connected to the direct reduction device 2 and the melting and gasifying furnace. 1, an outlet opening 8 for fine particles in this separator communicates with the melting and gasifying furnace, and an outlet opening 11 for coarse particles in this separator communicates with the melting and gasifying furnace. Equipment for producing sponge iron particles and liquid pig iron from lump iron ore, characterized in that it is in communication with a melting device or with means 13 for hot compaction, passivation or cooling. 26 Said coarse grain separator 7 is in the form of an inclined gravity chute or channel 38 having at least one connecting means 39, which branches downwardly from said channel, through which the spongy iron particles of bulk material pass. Claim 25, characterized in that, when conveyed through, the fine particles settle downwards and are metered out via the connecting means, while the coarse particles advance further and further.
Equipment listed in section. 27. Equipment according to claim 25, characterized in that the coarse separator 7 comprises an iron grate or a screen capable of receiving heat loads. 28. Equipment according to claim 27, characterized in that the iron grid or screen is vibrated by a vibrator. 29 The discharge openings 8 for the fines fraction of the coarse separator 7 communicate via at least one pipe 9 with a container 10 having discharge means, which container has at least one gravity feed pipe. 29. The equipment according to any one of claims 25 to 28, characterized in that the equipment is connected to the melting and gasifying furnace 1 via a line 17. 30 The gravity feed pipe 17 extends from above into the melting and gasifying furnace 1 to near the upper boundary of the coal fluidized bed formed in the melting and gasifying furnace, and a protrusion 35 in this pipe 17 extends into the melting and gasifying furnace 1. 30. The installation according to claim 29, characterized in that it is arranged in an arrangement similar to that of the tube and/or that a baffle plate (36) is arranged at the lower end of the tube. 31. The equipment according to claim 30, characterized in that the wall plate 36 has a truncated cone shape. 32 (a) A direct reduction shaft furnace 2 having at its top a charging means 3 for massive iron ore and a gas outlet 5 for used reducing gas (waste gas), and at its bottom having a direct reduction shaft furnace 2 for direct reduction from iron ore. (b) a melting and gasifying furnace 1 with discharge means 41 for sponge iron particles and a gas inlet 4 for hot reducing gas; Opening hole 17 for use, coal and additives,
15, 45 and a gas outlet 43 for the produced reducing gas (crude gas), with outlets 21, 22 for liquid pig iron and liquid slag in its lower region, and for forming a gasification region. a melting gasifier having at least one tuyere or blowing pipe 23, 23a above the slag level for entering gas and fine solids; (c) a cooling device 13a for hot sponge iron particles, comprising:
(d) a cooling device having at its top an inlet aperture 46 for hot sponge iron particles and an outlet 48 for cooling gas and at its bottom an outlet aperture 14 for cooled sponge iron particles and an inlet 49 for cooling gas; a waste gas scrubber 28 connected to the waste gas outlet 5 of the direct reduction shaft furnace 2; and (e) a plurality of conduits connecting the individual devices with valves and compressors. In an installation for directly producing sponge iron particles and liquid pig iron, a classification or sorting means 7a is provided for sorting out the sponge iron particles, which means is connected by a conduit 9 to the upper side of the melting and gasifying furnace 1. It has a fine particle outlet aperture 8 and a coarse particle outlet aperture 11 connected to the aperture 17, and the gas outlet 51 of the waste gas scrubber 28 is connected to the tuyere 23a. Equipment for directly producing sponge iron particles and liquid pig iron from lumpy iron ore, characterized in that the lower part of the iron ore is in communication with the lower part of the iron ore. 33 The intake opening 46 of the cooling device 13a
is connected to the discharge means 41 of the reduction shaft furnace 2 by a gravity feed pipe 6, and the outlet aperture 14 of the cooling device 13a is connected to the classification or sorting means 7a. The equipment according to claim 32. 34. The gas outlet 51 of the waste gas scrubber 28 is in communication with the CO ₂ separator 29, and the cooling gas inlet 49 of the cooling device 13a is in communication with the gas outlet 54 of the CO ₂ separator 29, and the cooling gas outlet 48 of the cooling device is located in the top part 42 of the melting gasifier 1 or in the exhaust gas conduit 6.
34. The installation according to claim 32 or 33, characterized in that it communicates with an injection nozzle (44) within one. 35 The outlet 43 for the reducing gas produced in the melting and gasifying furnace has at least one cyclone 62
and the separate solid material discharge openings 64 of this cyclone are connected to the lower tuyere 23 of the melting and gasifier 1 from the waste gas scrubber 28.
35. The installation according to any one of claims 32 to 34, characterized in that it is in communication with a conduit 66 to a. 36 (a) A direct reduction shaft furnace 2 having at its top a charging means 3 for bulk iron ore and a gas outlet 5 for the used reducing gas (waste gas), and at its bottom a direct reduction shaft furnace 2 for direct reduction from iron ore. (b) a melting and gasifying furnace 1 with discharge means 41 for sponge iron particles and a gas inlet 4 for hot reducing gas; Opening hole 17 for use, coal and additives,
15, 45 and a gas outlet 43 for the produced reducing gas (crude gas), with outlets 21, 22 for liquid pig iron and liquid slag in its lower region, and for forming a gasification region. a melting gasifier having at least one tuyere or blowing pipe 23, 23a above the slag level for injecting gas and fine solids; (c) a cooling device 13a for hot sponge iron particles, comprising:
2. A cooling device having at its top an inlet aperture 46 for hot sponge iron particles and an outlet 48 for cooling gas, and at its bottom an outlet aperture 14 for cooled sponge iron particles and an inlet 49 for cooling gas; a waste gas scrubber 28 connected to said waste gas outlet 5 of the reduction shaft furnace 2; and (e) a plurality of conduits connecting the individual devices with valves and compressors; In the equipment for directly producing iron particles and liquid pig iron, a classification or sorting means 7a is provided for sorting out the sponge iron particles, which means is connected by a conduit 9 to the upper opening of the melting gasifier 1. 17, and the intake aperture 46 of the cooling device 13a is connected to the direct reduction shaft furnace 2 by means of a gravity feed pipe 6. and the outlet opening 1 of the cooling device 13a.
4 is equipment for directly producing sponge iron particles and liquid pig iron from lumpy iron ore, which is connected to the classification or sorting means 7a. 37. The gas outlet 51 of the waste gas scrubber 28 is in communication with the CO ₂ separator 29, and the cooling gas inlet 49 of the cooling device 13a is in communication with the gas outlet 54 of the CO ₂ separator 29, and the cooling gas outlet 48 of the cooling device is located in the top part 42 of the melting gasifier 1 or in the exhaust gas conduit 6.
37. Equipment according to claim 36, characterized in that it communicates with an injection nozzle (44) within 1. 38 The outlet 43 for the reducing gas produced in the melting and gasifying furnace has at least one cyclone 62
and the separate solid material discharge openings 64 of this cyclone are connected to the lower tuyere 23 of the melting and gasifier 1 from the waste gas scrubber 28.
38. Installation according to claim 36 or 37, characterized in that it is in communication with a conduit 66 to a.