KR20000016600A - Device for producing sponge iron - Google Patents

Abstract

PURPOSE: A device for manufacturing a sponge iron is provided to introduce a reduction gas with a high temperature dust and dense carbon monoxide to around circumference of a reduction shaft through a bustle channel and a reduction gas inlet. CONSTITUTION: In a device for producing sponge iron from lumps of iron oxide in a reduction shaft (1), a hot, dust-containing and carbon monoxide-rich reduction gas is used. The reduction gas is generated in a gas generator by partial oxidation of solid carbon-containing materials and is in part supplied to the reduction shaft through several lateral reduction inlets (3) arranged at the same height around the circumference of the reduction shaft at the lower end of the reduction zone. The lumps of iron oxide are introduced into the reduction shaft through its top area and discharged as sponge iron at its bottom end. Additional reduction gas inlets (15) shaped as downwardly open channels (11) which extend from the outside to the inside of the reduction shaft and/or shaped as ducts which extend obliquely downwards from the outside to the inside of the reduction shaft and have open inner ends are arranged below the plane of the lateral reduction gas inlets. Reduction gas may thus be also supplied to the radial inner area of the reduction shaft, so that the introduction of dust by the reduction gas is not limited to the outer area of the bulk material in the reduction shaft.

Description

Apparatus for producing sponge iron

By reducing the iron oxide mass in the reduction shaft with a reducing gas containing dust from the molten gasifier in the iron ore reduction melting plant, only a portion of the empty volume of the bulk material in the reduction shaft is reduced together with the reducing gas. It can be used to receive the dust introduced into it. In addition to the dust introduced with the reducing gas into the plant through which the reduction shaft is connected to the molten gasifier via a downward pipe, an additional amount of dust is introduced together with the gasifier gas into the lower region of the reduction shaft through the downward pipe and the discharge device. do. The dust content of this gasifier gas is many times higher than the dust content of the reducing gas which is dedusted in advance in the hot gas type cyclone and intentionally introduced into the reduction shaft. In addition to this dust, the dust is additionally carried back to the reduction shaft by air separation of the released sponges and in the case of calcined aggregates, by the upward flow of gasifying gas. The total dust causes further increased dusting of the lower region of the reduction shaft and the uncontrolled release of the corrugated iron by the release device as well as the channeling and hanging of the bulk material. A particularly disadvantageous effect is that the dust passing through the downward pipe from the melt gasifier to the reduction shaft likewise contains not only partially degassed tar-containing coal particles, but also other compositions resulting in spheroidisation.

The invention relates to an apparatus according to the preamble of claim 1.

1 is a vertical sectional view of a reduction shaft;

FIG. 2 is a horizontal sectional view of the reduction shaft according to FIG. 1 between the region and bustle region of each of the channels and ducts for further introduction of reducing gas; FIG.

3 is a vertical sectional view of a channel for conveying reducing gas;

By more concentrated dusting of the iron oxide bulk material in each of the bustle zone and the inlet zone of the reducing gas, the pressure difference between the melt gasifier and the lower region of the reduction shaft increases, so that the highly dusted gasified gas is directed downward. It rises up through a pipe and screw type extractor, through which the gas directly accesses the less dusted bulk material in the center of the reduction shaft. Due to this increased pressure difference, the air separation becomes more and more intense in the downward pipe, the content of dust becomes higher and higher, and the bulk material in the lower region of the reduction shaft can be enriched with circulating dust, The flow of undisturbed gas consisting of a very high dust content from the channeling and melt gasifiers into the reduction shaft, a known phenomenon which is sufficient to provide the bulk of the bulk material with very low pressure differences due to the high frictional forces in the thick bulk material. Brings about. Part of the dust is also transported upwards from the lower region of the reduction shaft into the reduction zone to guide the dusting and channeling of the bulk material. When excessively small sized powder is introduced with coal by employing more coal in a coal mixture that decomposes well at high temperatures, this intensive dusting occurs in the bustle zone, where a very increased temperature causes gasification. Appear in the apparatus, resulting in greater decomposition of coal with more concentrated decomposition of ore in the reduction shaft and with failure and partial failure of recycling of dust respectively. When this happens, the reduction shaft needs a rather long time until the dust is removed because part of the dust is repeatedly transported upwards through the formed channels.

A portion of the remaining empty volume is introduced with the raw material and filled by the fine particles partially generated in the reduction shaft by the reduction of the iron carrier and the calcination of the aggregate. As a result, the capacity of the reduction shaft is greatly limited because a large part of the empty volume must be maintained for the flow of reducing gas through the bulk material, and therefore the minimum amount of reduction required for the reduction of iron oxide and the calcination of aggregates. The gas can be guided through a reduction shaft with an appropriate upper pressure drop. By exceeding a certain pressure drop depending on particle size, particle composition and empty volume of the bulk material, not only does the "substrate" of the bulk material occur, but also the cross flow and channeling of some reducing gas through the channel without participating in the reduction process. do. The results from this lead to low levels of metallization, low carburization of spongy iron, low levels of calcination of aggregates, as well as low plant performance. Thus, for normal operation, a minimum specific amount of reducing gas is required which is guided through the reduction shaft without channeling and swelling of the bulk material. The specific demand for this reducing gas depends on the degree of oxidation of the reducing gas, the iron content of the iron oxide, the decomposition properties of the iron oxide employed at low temperatures, the amount and decomposition properties of the aggregates, as well as other factors, and about 1050 m 3 per ton of iron oxide. It is a reducing gas. The pressure drop is determined by the large cross section of the reduction shaft in the lower region due to the high temperature of the gasified gas and the low pressure drop in the bulk material used as the gas barrier means for the gasified gas which is not dedusted through the downward pipe. Although brick-lined hot gas type cyclones with adequate efficiency are employed as dedusting units for reducing gases, they still additionally contain a significant amount of dust, which results in a relatively low upper margin towards the top with a certain amount of reducing gas. Is given. By introducing the reducing gas into the bustle zone, only a portion of the free volume of the bulk material still freely available for dust separation at the radial center of the reduction shaft is rarely used, and therefore is guided through it. There is less specific amount of reducing gas available and the outer ring of bulk material in the gas inlet is dusted higher than necessary. Next, channeling and presence starts at this outer ring. As the diameter of the reduction shaft becomes larger and larger, the specific amount of reducing gas that can be induced through the reduction shaft without suspending and channeling becomes smaller.

Thus, carburizing and increased reduction of the barbed iron are obtained, and a low dusted bulk material in the radially central region is used for dust separation, and a greater pressure drop occurs in the bulk material in the lower region of the reduction shaft. The cyclone of the hot gas type, which has a greater pressure drop and a higher level of separation, can be employed to dedust the gasified gas used as the reducing gas, and contains dust flowing through the downward pipe into the reduction shaft. The amount of gasified gas being processed is very limited and no additional pressure difference occurs through the pipe connection and the downstream pipe, respectively, between the melt gasifier and the lower part of the reduction shaft by the uniform dusting of the entire bulk material. It is an object of the present invention to improve conventional devices in that they do not.

This object is solved according to the invention by the features appearing in the characterizing part of claim 1. Advantageous improvements of the device according to the invention emerge from the dependent claims. Next, the present invention will be described in detail according to the embodiment shown in the drawings.

The cylindrical reduction shaft 1, which is charged from the top through the distribution pipe 4, in which only two are shown in FIG. 1, ie from the top of the reduction zone, has a downwardly extending cross section and is approximately in the upper region A. It consists of a cone of 2 °, a cone of about 0.5 ° in the center portion B of about 5 m height and a cone of 2.5 ° in the lower region C of about 2 m height. The reduction shaft also consists of several funnel shaped product outlets 5 in the lower region, where only two are shown in FIG. 1 and six are shown in FIG. 2. The pipe connection 5a, which is preferably a funnel-shaped extension of each of the product outlets, extends directly to the bottom, which is formed horizontally or slightly curved of the reduction shaft 1. The product outlet 5 is formed by a baffle made of refractory material, ie an intermediate wall 9, and a conical block 10 in the radial center of the reduction shaft 1 having a water-cooled or nitrogen-cooled mount 6. . An open channel formed as a half-pipe shell with an insulating material and an enclosing protective tube 13 in the lower region between these pipes which are eccentric to each other, as well as the side walls which are arranged and extended on the support 12 ( A water cooled support 12 with 11 is shown in FIG. 3. A support 12 having a channel 11 is arranged on the product outlet 5 and supported radially inward on the mount 6 of the block 10 made of refractory material. As one alternative configuration, the inclined inwardly duct 8, cut forward at an angle, is shown in phantom in FIG. Reducing gas from the outside is introduced into each of the channel 11 and the duct 8 as indicated by arrow 15. In the introduction of the reducing gas, the side walls of the channels 11 are drawn deeper to avoid the horizontal plane where accumulated dust can remain, and the brick lining is carried out more strongly. A larger gradient can be obtained when the gas connection 15 is placed laterally and obliquely with respect to the support 12. Advantageously, at the bottom end of the pipe connection 5a each discharge device, not shown in the figure, is arranged for sea level iron.

The normal operation of such a plant employs bulk ore by introducing reducing gases containing hot dust and enriched with carbon monoxide only around the circumference of the reduction shaft 1 through the reducing gas inlet 3 as well as through the bustle channel 2. By means of very small reduction shafts, and by using high quality pellets, only by very large reduction shafts. In comparison, part of the reducing gas enters the radial center of the reduction shaft 1 in order to achieve stable operation with a wide range of performance and with a higher margin in the specific amount of reducing gas, the dust content of the reducing gas and the selection of raw materials. This is almost essential for large plants operating with conventional raw materials. A reduction shaft diameter of about 5-6 m is considered to be the boundary between these two aspects.

By using a reducing gas having a larger reduction shaft, containing hot dust and enriched with carbon monoxide, several funnel shaped product outlets 5 are formed by baffles of refractory material in the lower region of the reduction shaft. It consists of an intermediate wall 9 and a conical block 10 in the central region and is provided with a mounting 6 which projects into the baffle through the bottom of the reduction shaft 1 and is cooled with water or nitrogen. These mountings are used as anchors for the water-cooled support 12, while at the same time the channels 11 for introducing the reducing gas under the reduction shaft 1 into the mainly radial central region are not only suspended but also It is also used as a support for the duct 8. Brick-lined, preferably welded to the bottom of the reduction shaft 1 or secured with a flange joint to extend the funnel-shaped product outlet 5, for sliding the material into the funnel-shaped pipe connection 5a. The required steep inclination angle is provided so that a bulk material of higher height is provided as a gas shutoff means to reduce the pressure difference between the melt gasifier and the reduction shaft 1 at the same time. The introduction of a portion of the reducing gas through the inlet 15 into the radially central region of the reduction shaft 1 can be achieved by lateral reducing gas through a channel 11 and / or one water-cooled duct 8 each made of at least one heat-resistant steel. The channel 11 and / or the duct 8 should preferably occur on each product outlet 5 and on each intermediate wall 9, respectively, below a plane of about 2 m below the plane of the inlet 3. Is placed directly. The channel 11 for introducing and distributing the reducing gas is formed by a half pipe shell made of heat-resistant steel having an extended side wall, and is disposed on the water-cooled tubular support 12 from the top, thereby extending the extended side of the half pipe shell. This downwardly open channel 11 is formed. This shape is such that the open channel 11, which is almost horizontal or slightly inclined downward, is not blocked by material or dust, and a very large surface of the bulk material is relaxed to introduce the reducing gas and for dust separation from the introduced reducing gas and It is advantageous in that good conditions for removing the separated dust in the upper region are provided in this upper region by this bulk material which drops rapidly and becomes very loose. In a reducing gas containing dust, access to the area of the bulk material dusted to a smaller size is made possible over the entire cross section of the reduction shaft 1.

It is used as a gas blocking means and, without participating in the reduction process, the large volume portion of the lower portion of the reduction shaft 1, which occupies almost one third of the volume of the reduction shaft 1, by introducing cooler reducing gas It is used for higher carburizing of sponge iron and reducing the rest. Because of this, this reduction zone and thus the entire reduction shaft can be made smaller and easier, whereby an important advantage is due to the reduction shaft having a large span of support as well as a medium load and a total load of about 1500 tons or more. Occurs.

Higher carbon content and higher metallization of sponges reduce the energy requirements of the molten gasifier and participate in more uniform operation and better quality of the sponges. Thus, the reducing gas is guided through the inlet 15 at a temperature lower than the temperature of the remaining reducing gas in order to provide better conditions for carburizing of the sponge iron in the lower region of the reducing shaft 1. About 50 ° to 100 ° C. lower temperatures are considered as optimum temperatures for the partial flow of this reducing gas. However, further cooling to about 650 ° C., which is an optimal value for carburizing iron sponges, results in cooling at the center of the shaft, resulting in lower metallization in this region. By introducing a cooler reducing gas, in spite of the high exothermic budar reaction, the bulk material is cooled in this critical region for spheroidization, the shape of which is driven by the water cooling support 12 and / or the water cooling duct 8. It is avoided with reducing the weight of the material column thereon from the bulk material. As is known, the spheroids of calcined agglomerates and tar-containing coal particles are not sufficiently degassed, so that the degassed products also contain water vapor so that the calcined agglomerates and tar-containing coal particles are bound to binders and enclosed spongy iron particles and residual dust. Since it serves as the main component of the spherical material having the component, the temperature of the bulk material and its pressurization are of great importance. Once the spheroid is formed, the bulk material in the region of the top of the reduction shaft 1 descends at low speed. Local overheating by intensive dusting and strong exothermic budar reactions is also allowed to occur in some regions of the reduction zone. The arrangement of the screw type extractor at the lower end of the pipe connection 5a is regarded as an advantageous improvement. With this configuration, the reduction shaft 1 does not need to be cleaned during the replacement or large repair of the screw type extractor, thereby avoiding long non-production periods and high initialization costs of living organisms.

As a result of having the open channel 11 downward, the best conditions for transporting the separated and separated dust appear. The half-pipe shell of the channel 11 with an extended side wall can be made with a few weld seams either integrally or in a non-critical position, which is used as thermal insulation and wear protection for the water cooled support 12. . In order to minimize the heat loss of the support 12, the shell is provided with an additional protective tube 13 made of heat resistant steel. The lower region, the intensive temperature loaded between two pipes located eccentrically with each other, is filled with a thermally insulating fabric 14, and the protective tube 13 is preferably slitted to avoid deformation by other thermal loads. In the upper region in the transverse direction with respect to the axis. The support 12 and / or duct 8 is supported in the wall of the reduction shaft 1 and on the mounting 6 fitted inside the intermediate wall 9 and the block 10, thus being long for the construction of a large reduction shaft. There is no need for a strong and strong support 12 and / or a duct 8. The use of a mounting 6 fitted in a conical block 10 for supporting a pipe support 12 and a channel 11 as well as a mounting 6 fitted in an intermediate wall 9 for supporting a duct 8. It is an advantage. The water-cooled duct 8 is arranged at an inclined angle and is cut at an oblique end in order to enlarge the ejection surface of the bulk material and to avoid blockage in the duct 8.

With the conical selection of the reduction zone of the reduction shaft 1, the amount of dust introduced, the swelling of iron oxides, the decomposition properties and the granular composition of iron oxides and agglomerates as well as the content of carbon monoxide in the reducing gas are taken into account. In the region of the side inlet 3 for the reducing gas to a height of about 2 m or more where the highest dusting and highest risk occurs to suspend the bulk material, a high cone of about 2.5 ° is chosen so that the bulk material It is allowed to open and receive dust. Further increased reduction of the cross section towards the upper side is advantageous for accommodating dust, but this results in a higher increase in the specific pressure drop in the upper region of the reduction shaft 1 by increasing the gas temperature and gas velocity respectively. In this region, carburizing of the sponge iron and heating of the whole region are caused by the high-heating budar reaction, so that the decrease in the amount of gas due to carburization of the sponge is more than compensated for by the increase in the amount of gas based on the concentrated calcination of the aggregate Big. With a gas temperature rise of 80 ° C, the specific pressure drop increases by 15% over a certain cross section. For this reason, a smaller cone-shaped angle of about 0.5 ° is chosen in this region which is about 3 to 5 m high. The greater weight of the material column present in the upper part of the region appears for a certain pressure drop and smaller angle due to more concentrated dusting in the upper region. Because of this, higher pressure drops and more concentrated dusting in this area can be tolerated. In the region above, a cone of about 2 ° is considered optimal.

In some cases, charging the reduction shaft 1 with iron oxide mixed with the agglomerate takes place via a distribution pipe 4 arranged in an upper region in the circle whose center is at the longitudinal axis of the reduction shaft 1. The number of distribution pipes corresponds at least twice the number of product outlets 5. As a larger reduction shaft, this distribution pipe has two circles in order to avoid intensive gas flow in the center and in the edge region of the reduction shaft caused by the intensive M-profile and to minimize the treatment of budding. And must be mounted in plurality. The distribution pipe 4 is arranged symmetrically towards the axis of the product outlet 5. Thus, the bulk material below this distribution pipe 4, which is more dense fine granules and descends at a lower speed than this coarse bulk material, is on the two catchment regions of the screw type conveyor, ie each channel 11. And through each of the two distribution pipes 4 arranged directly between two adjacent intermediate walls 9 of this channel.

The amount of reducing gas introduced through the inlet 15 into the central region of the reduction shaft 1 is advantageous about 30% of the total amount of reducing gas for the medium-sized reducing shaft, so that the bustle channel ( About 70% of the reducing gas is supplied through 2) and inlet 3. By this reduction of 30% of the amount of gas transported through the bustle channel 2, about 30% of the bulk material's load is also reduced in this region with dust, thereby reducing the channeling and stringing of the bulk material during normal operation. Sieve no longer expected A small amount of reducing gas introduced through the downwardly open channel 11 also flows into the outer ring, but the main amount flows into the radial central region in the bulk material of the reduction shaft 1, dusted to a smaller size. do. With a large reduction shaft, the introduced amount of reducing gas into the radial center region of the reduction shaft will correspondingly increase.

The introduction of reducing gas into the central region of the reduction shaft through a water-cooled duct 8 mounted with an inliner made of heat-resistant steel and facing downward obliquely conveys a portion of the reducing gas into the radial central region of the reduction shaft 1. However, this shows a different possibility, but this is a disadvantage that the relatively small flow surface concentrates the bulk material in the inlet region of the reducing gas which is also a disadvantage in this region.

For this reason, it is contemplated as a preferred alternative to add the reducing gas into the central region of the reduction shaft 1 only through the channel 11 which opens downward.

Thus, the addition of reducing gas through the duct 8 into the central region of the reduction shaft 1 is a preferred alternative for realizing a smaller reduction shaft.

Each of the support 12 and the duct 8 also supports a large portion of the weight of the material column lying thereon, alleviating and relieving the bulk material in the product outlet 5, with the bridging narrowing down this funnel shape. It does not occur in the region.

The channels 11 may be mounted in a star shape or parallel to each other. The conveying pipes towards these channels and / or ducts 8 have downward gradients and are therefore not blocked and are caused by dust accumulations which push the bulk material back during pressure changes in this system.

An extended side wall of the channel 11 which opens downward at a certain distance is provided with a reinforcement and a distance piece 16 so that the shrinkage of the channel caused by the bulk material and compressing the walls parallel to each other is avoided.

Claims (21)

The reducing gas is produced in the gas generator by partial oxidation of the solid carbon-containing material, and through several side reducing gas inlets 3 arranged at the same height around the circumference of the reduction shaft 1 at the lower end of the reduction zone. Supplied to the reduction shaft 1, the iron oxide mass is introduced into the reduction shaft 1 through the upper region of the reduction shaft and contains hot dust and is rich in carbon monoxide, which is released as spongy iron at the bottom end of the reduction shaft. Apparatus for producing spongy iron from agglomerates of iron oxide in a reduction shaft (1) by using a reducing gas, as an at least one downward open channel extending from the outside into the radial center region of the reduction shaft (1) and / or At least the one extending inclined downwardly in the radial central region of the reduction shaft 1 and having one open inner end; An additional reducing gas inlet (15) formed as one duct (8) is arranged below the plane of the side reducing gas inlet (3). 2. The gas generator according to claim 1, wherein the gas generator is a melt gasifier and the lower end of the reduction shaft 1 melts at least through the downcomer to feed the sponges from the reduction shaft 1 into the melt gasifier. And is connected to the head of the gasifier. Device according to claim 1 or 2, characterized in that the funnel-shaped product outlet (5) is formed by a baffle (9,10) of refractory material in the lower region of the reduction shaft (1). 4. Device according to claim 3, characterized in that the baffle is formed of a radially extending intermediate wall (9) and a block (10) extending conically downward in the radial central region of the reduction shaft (1). The inner end fitting 6 of the at least one channel 11 and / or the at least one duct 8 is fitted in the baffles 9, 10. Device. Device according to one of the claims 3 to 5, characterized in that each one channel (10) is arranged on a respective intermediate wall (9). Device according to one of the claims 4 to 6, characterized in that each one duct (8) is arranged on a respective intermediate wall (9). 8. The device according to any one of the preceding claims, wherein each channel (11) consists of a heat resistant steel and is arranged under and suspended above a water cooling support (12) extending in the same direction. 9. Device according to claim 8, characterized in that the channel (11) is formed as a half pipe shell which is opened downward and has a parallel wall extending downward and is disposed on the support (12). 10. Device according to claim 8 or 9, characterized in that the supports (12) are each surrounded by a protective tube (13), with the spaces between them being filled with a heat insulating fabric (14). Device according to claim 9 or 10, characterized in that the height of the parallel walls is reduced towards the center of the reduction shaft (1). Device according to one of the preceding claims, characterized in that the channels (11) are arranged in a star-shaped manner or parallel to one another. The device according to claim 1, wherein the duct is water cooled and is provided with lining of heat resistant steel. Apparatus according to claim 1, characterized in that the conveying pipe has a downward slope towards the channel (11) and / or the duct (8). The device according to claim 3, wherein the screw type extractor is provided at the lower end of each said product outlet (5). 16. The reduction shaft (1) according to any one of the preceding claims, wherein the reduction shaft (1) is about 2.5 ° in the lower region up to about 2 m above the reduction inlet (3) on the side, and from about 2 m Apparatus characterized in that it gradually expands conically from top to bottom, about 0.5 ° up to about 5 m and else about 2.0 ° up. 17. The method according to any one of claims 3 to 16, in the upper region of the reduction shaft 1, the number of which is twice the number of the product outlets 5, in a circumferential circle towards these product outlets and A symmetrically arranged distribution pipe (4) is characterized in that it is provided for charging iron oxide and, in the case of agglomerates, aggregates. The reducing gas is produced in the gas generator by partial oxidation of the solid carbon-containing material, and through several side reducing gas inlets 3 arranged at the same height around the circumference of the reduction shaft 1 at the lower end of the reduction zone. Supplied to the reduction shaft 1, the iron oxide mass is introduced into the reduction shaft 1 through the upper region of the reduction shaft, discharged as sponge iron at the bottom end of the reduction shaft, and from the outside of the reduction shaft 1 As at least one downward open channel extending into the radial central region and / or as at least one duct 8 extending obliquely downward in the radial central region of the reduction shaft 1 and having one open inner end. An additional reducing gas inlet 15 contains hot dust and carbon monoxide, arranged below the plane of the side reducing gas inlet 3. In a method for producing spongy iron from agglomerates of iron oxide in a reduction shaft (1) by using a rich reducing gas, the reducing gas supplied through the channel (11) and / or the duct (8) The method characterized in that the lower temperature than the reducing gas supplied from the lower end. 19. The method according to claim 18, wherein the temperature of the reducing gas supplied through the channel (11) and / or the duct (8) is about 50 ° C lower than the temperature of the reducing gas supplied at the lower end of the reducing zone. The reducing gas is produced in the gas generator by partial oxidation of the solid carbon-containing material, and through several side reducing gas inlets 3 arranged at the same height around the circumference of the reduction shaft 1 at the lower end of the reduction zone. Supplied to the reduction shaft 1, the iron oxide mass is introduced into the reduction shaft 1 through the upper region of the reduction shaft, discharged as sponge iron at the bottom end of the reduction shaft, and from the outside of the reduction shaft 1 As at least one downward open channel extending into the radial central region and / or as at least one duct 8 extending obliquely downward in the radial central region of the reduction shaft 1 and having one open inner end. An additional reducing gas inlet 15 contains hot dust and carbon monoxide, arranged below the plane of the side reducing gas inlet 3. In the method for producing spongy iron from the iron oxide mass in the reduction shaft 1 by using a rich reducing gas, the portion of the reducing gas supplied through the channel 11 and / or the duct 8 is entirely And about 30% of the amount of reducing gas. The reducing gas is produced in the gas generator by partial oxidation of the solid carbon-containing material, and through several side reducing gas inlets 3 arranged at the same height around the circumference of the reduction shaft 1 at the lower end of the reduction zone. Supplied to the reduction shaft 1, the iron oxide mass is introduced into the reduction shaft 1 through the upper region of the reduction shaft, discharged as sponge iron at the bottom end of the reduction shaft, and from the outside of the reduction shaft 1 As at least one downward open channel extending into the radial central region and / or as at least one duct 8 extending obliquely downward in the radial central region of the reduction shaft 1 and having one open inner end. An additional reducing gas inlet 15 contains hot dust and carbon monoxide, arranged below the plane of the side reducing gas inlet 3. In the method for producing spongy iron from the iron oxide mass in the reduction shaft 1 by using a rich reducing gas, the reducing gas introduced at the lower end of the reducing zone is mostly removed from the dust in the high temperature type cyclone. How to feature.