CA2365982A1 - Device for producing hot-briquetted metallic sponge, especially hot-briquetted sponge iron - Google Patents
Device for producing hot-briquetted metallic sponge, especially hot-briquetted sponge iron Download PDFInfo
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- CA2365982A1 CA2365982A1 CA002365982A CA2365982A CA2365982A1 CA 2365982 A1 CA2365982 A1 CA 2365982A1 CA 002365982 A CA002365982 A CA 002365982A CA 2365982 A CA2365982 A CA 2365982A CA 2365982 A1 CA2365982 A1 CA 2365982A1
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- fine particles
- briquetting
- hot
- briquetting press
- sponge
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
- B29C44/02—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles
- B29C44/08—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles using several expanding or moulding steps
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/24—Binding; Briquetting ; Granulating
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/0086—Conditioning, transformation of reduced iron ores
- C21B13/0093—Protecting against oxidation
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- Metallurgy (AREA)
- Mechanical Engineering (AREA)
- Manufacture Of Iron (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
- Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)
Abstract
The invention relates to a device for producing hot-briquetted metallic sponge, especially hot-briquetted sponge iron, from hot metallic sponge fines.
Said device comprises at least one briquetting press (4), a means (6) for removing the fines from the briquettes produced by the briquette press (4), said means being mounted downstream of the briquette press (4). The device further comprises a means for returning the removed fines to the briquette press (4). The returning means is configured as a pneumatic conveyor means (20, 21), thereby reducing the costs for investment, service and maintenance and rendering the device more compact and space-saving.
Said device comprises at least one briquetting press (4), a means (6) for removing the fines from the briquettes produced by the briquette press (4), said means being mounted downstream of the briquette press (4). The device further comprises a means for returning the removed fines to the briquette press (4). The returning means is configured as a pneumatic conveyor means (20, 21), thereby reducing the costs for investment, service and maintenance and rendering the device more compact and space-saving.
Description
Plant for producing hot-briquetted metallic sponge, in particular hot-briquetted iron sponge The invention relates to a plant for producing hot-s briquetted metallic sponge, in particular hot-briquetted iron sponge, from hot metallic sponge which is in the form of fine particles, which plant. comprises at least one briquetting press, a device for separating fine particles from briquettes formed by means of the briquetting press, which device is connected downstream of the briquetting press, and a device for returning the fine particles which have been separated off to the briquetting press, and to a process using this plant.
A plant for producing hot-briquetted iron sponge from hot iron sponge in fine particle form is described, for example, in US-A-5,192,486. According to US-A-5,192,486 oxide charge material is reduced in the solid state to iron by reduction gas using a direct reduction device.
To compress the reduced material so as to form a small surface for reoxidation, hot-briquetting is provided for the reduced material.
In the known plant, the iron sponge is compressed by means of a continuous pressing process using roller presses. The resulting briquette strand is then separated into individual briquettes by crushing in trommels or in impact crushers. The resulting quantity of fine particles, known as fines and chips, is returned to the briquetting presses after a screening operation, in order to save charge material. This takes place by means of hot bucket elevators at temperatures of 550-700°C under an inert atmosphere. The briquettes which are produced during the screening are discharged by means of cooling conveyors.
The fine particles and their very high temperature cause considerable wear to the moving parts of the hot bucket elevator, particularly to the chain or chain connecting elements, and therefore entail an extraordinarily high level of maintenance. A further drawback is the relatively large amount of space taken up by the return system as a whole, i.e. the hot bucket elevator including the supplying fines legs, which are understood as meaning downcomers for the material in fine particle form. This is because the hot bucket elevator is usually arranged between individual briquetting lines, thus increasing the space taken up between the briquetting lines. Therefore, taking into account the required angle of discharge for the fine particles conveyed by the fines legs, a larger overall height of the briquetting building is also required.
A hot bucket elevator can usually be fed from at most two briquetting lines, with the result that there is a correspondingly increased demand for hot bucket elevators if more than two briquetting lines are provided. In the known plant, a correspondingly larger number of discharge devices for the briquettes or, if, as well as the returning of the fine particles, cooling of the fine particles is alternatively provided, a correspondingly larger number of cooling devices, for example flight separators, is also required.
In the known plant, the returned material is also cooled by applying inert gas to the hot bucket elevator, which has an adverse effect on the briquetting performance and/or on the wear to the briquetting press, particularly if the fine particles are returned directly to the briquetting press. The investment, maintenance and repair costs are therefore very high for the known plant.
The present invention is based on the object of overcoming the drawbacks and difficulties of the known plant, in particular of minimizing the investment, repair and maintenance costs, and of simplifying processing of the fine particles. Furthermore, it is intended for it to be possible to reduce the height of the briquetting building and to reduce the construction outlay overall.
S According to the invention, this object is achieved by the fact that the return device is designed as a pneumatic conveyor device.
This results in a considerable saving on investment, repair and maintenance costs for the briquetting area.
Furthermore, space can be saved in the briquetting area. This is because, unlike a hot bucket elevator, the return device according to the invention does not have to be arranged between individual briquetting lines. Taking into account the space saving which is achieved according to the invention or the flexible configuration of the briquetting area, the height of the briquetting building can be reduced by 10 to 15%.
Furthermore, the number of separating devices for the fine particles, generally screens, can be optimized, i.e. it is possible to provide a screen for two or more briquetting lines. Consequently, it is also possible to reduce the number of cooling conveyors which are used to discharge the briquettes, and to feed a cooling conveyor from, for example, four briquetting lines.
In the plant according to the invention, the pneumatic conveyor device preferably opens out into a storage hopper connected upstream of the briquetting press.
According to a further preferred embodiment, the pneumatic conveyor device opens out into a feed line which guides the metallic sponge which is in fine particle form to the briquetting press and/or to the storage hopper.
The use of these measures improves the distribution of the returned fine particles in the overall stream of material, i.e. in the metallic sponge in fine particle form. The returned fine particles are brought to the optimum briquetting temperature through contact with hot metallic sponge in fine particle form. This results in the advantage of reduced wear to the briquetting tools. The grain size for the returned material can be increased, so that the quantity of relatively large fine particles, known as chips, which cannot be returned can be reduced or eliminated. This results in an increase in the effective discharge capacity of the briquetting, i.e. the output of briquettes.
Preferably, the feed line leading to the storage hopper is designed as a riser, the riser being connected downstream of at least one reduction reactor for the direct reduction of metal-oxide-containing material which is in fine particle form. In this context, the term riser is understood as meaning a substantially vertical section of pipe which has a refractory lining and through which the metallic sponge in fine particle form is conveyed pneumatically upward by means of the process gas of the reduction reactor. Via the riser, the returned fine particles, together with the hot metallic sponge in fine particle form, pass into the storage hopper, from where they are fed to one or more briquetting presses via feed legs. When the fine particles are being returned to the riser, the section of pipe of the pneumatic conveyor device required for this purpose can be kept very short.
Advantageously, a charge container for receiving the fine particles which have been separated off and are to be returned is connected upstream of the pneumatic conveyor device. Expediently, locks are provided for the purpose of blocking the charge container with respect to the separating device, on the one hand, and with respect to the briquetting press or the storage hopper or the feed. line leading to the briquetting press or to the storage hopper, on the other hand. As a result, the charge container is sealed with respect to the other components and may, for example, be fed with the fine particles and emptied discontinuously.
Advantageously, a control unit for the locks is provided, which control unit is designed to be locked by a blocking device provided at the outlet for the metallic sponge in fine particle form from the reduction reactor.
According to a preferred embodiment, a carrier gas used in the pneumatic conveyor device is process gas of a direct reduction device. This prevents reoxidation of the fine particles and, moreover, is approximately at the temperature of the fine particles. The process gas is advantageously also at the pressure prevailing in the reduction reactor.
According to a further preferred embodiment of the plant according to the invention, a device for cooling and then discharging a partial stream of the fine particles which have been separated out by means of the separating device is provided. The cooling device is preferably designed as a flight separator. The quantitative flow rate of fine particles supplied to the cooling device can be controlled by slides.
However, it is also possible to provide what is known as a fines diverter.
The plant according to the invention allows considerable simplification of the cooling device which is known per se, since only one delivery point for hot material is required. The result is savings in the area of the cooling device itself and in the area of the additional devices required, for example the fines diverter.
A highly simplified design, as an alternative cooling device, is a trough which is filled with water for quenching the fine particles and from which the cooled fine particles can be removed, for example by means of a wheel loader.
Preferably, downstream of the separating device there is a buffer container, from which lines lead to the return device and/or to the cooling device. This results in greater flexibility when splitting the fine particles into a partial stream to be returned and a further partial stream to be cooled and discharged.
Furthermore, the material to be returned can be delivered both to the return device and to the cooling device in each case discontinuously or in batches.
The return device and/or the buffer container is/are expediently thermally insulated, in order to minimize cooling of the fine particles which are to be returned.
In the plant according to the invention, a device for dividing a briquette strand which is formed in the briquetting press into individual briquettes, preferably a trommel and/or an impact crusher, is preferably connected downstream of the briquetting press. The briquette strand is separated into individual briquettes by means of the dividing device, producing the fine particles which are to be returned as well as the briquettes.
Preferably, in the plant according to the invention, a plurality of briquetting lines, each comprising a briquetting press and, if appropriate, a dividing device and a separating device, is provided, the briquetting lines opening out together to a single return device. It is particularly preferable for four briquetting lines to be provided, specifically in a rectangular arrangement as seen in plan view. Beneath the four briquetting lines or the associated separating device(s), by way of example a single buffer container is arranged, each individual separating device only being connected directly to the buffer container by one fines leg.
A process for producing hot-briquetted metallic sponge, in particular hot-briquetted iron sponge, from hot metallic sponge which is in the form of fine particles, in which process the metallic sponge is hot-briquetted by means of at least one briquetting press, then fine particles are separated from the briquettes formed in this way, in particular by screening, and the fine particles which have been separated off are returned to the briquetting press, is characterized in that the fine particles are returned by means of pneumatic conveying.
Preferably, the fine particles are returned to a storage hopper, which is connected upstream of the briquetting press, and/or to a feed line which guides the metallic sponge in fine particle form to the briquetting press and/or to the storage hopper.
Advantageously, the fine particles are returned continuously or discontinuously by means of a process gas from a direct reduction process.
A modified embodiment of the process according to the invention is characterized in that the fine particles are returned discontinuously by means of an individual conveyor container.
According to a further preferred embodiment, a partial stream of the fine particles which have been separated off is cooled and discharged.
According to yet another preferred embodiment, a briquette strand is formed by means of the briquetting press, and the briquette strand is divided into individual briquettes before the fine particles are separated off.
The briquetting of the metallic sponge which is in fine particle form and/or the dividing of the briquette strand into individual briquettes and/or the separating of the fine particles advantageously takes place in a plurality of briquetting lines, preferably in four briquetting lines, the returning of the fine particles which have been separated off taking place in a single return line.
The invention is explained in more detail below with reference to the drawing ( Figs . 1 to 5 ) , Figs . 1 and 2 each presenting a diagrammatic illustration of a plant which is known from the prior art and corresponds to a modified embodiment of the plant described in US-A-5,192,486, and Figures 3 to 5 each showing preferred embodiments of the invention.
In the known plant which is illustrated in Fig. 1, hot iron sponge which is in the form of fine particles and is conveyed out of a reduction reactor (not shown in more detail in Fig. 1) by means of a carrier gas, passes into a storage hopper 1. The carrier gas used for the iron sponge in fine particle form is reduction gas, which is then extracted from the storage hopper 1 via an outlet line 2.
From the storage hopper 1, the hot iron sponge which is in fine particle form passes via feed legs 3 into briquetting presses 4, two of which can be seen in Fig. 1. The briquetting presses 4 are arranged in parallel and are simultaneously fed with iron sponge in fine particle form from the storage hopper 1. In the known plant, however, it is also possible, for example, to provide four briquetting presses 4, as shown in Fig. 2.
The briquetting presses 4 are designed as roller presses, by means of which briquette strands are formed, which are divided into individual briquettes in _ g _ downstream trommels 5. In the plant shown in Fig. 1, each briquetting press 4 is assigned one trommel 5 for dividing the briquette strand.
During the briquetting itself and during the dividing of the briquette strand in the trommels 5, a considerable quantity of fine particles is produced, and these particles, if they were to be discharged in this form without further treatment, would be subject to high levels of reoxidation. To avoid such reoxidation, the fine particles are fed back for briguetting.
For this purpose, in the plant which is known from the prior art, the fine particles are separated from the briquettes by means of screens 6. In the known plants illustrated in Figs. 1 and 2, in each case one screen 6 is provided for in each case one briquetting press 4 and one trommel 5.
The briquettes pass via lines 7 to cooling conveyors 8;
in accordance with Fig. 1 a dedicated cooling conveyor 8 is provided for each briquetting line, comprising a briquetting press 4, a trommel 5 and a screen 6. As indicated by a dashed line in Fig. 1, lines 7a from two further briquetting lines, which are not shown in more detail in Fig. 1, also open out onto each cooling conveyor 8. In this case, one cooling conveyor 8 is provided for in each case two briquetting lines, as can be seen in particular from Fig. 2.
On the cooling conveyors 8, cooling gas passes around the briquettes as a result of the cooling gas being forced or sucked through a layer formed by the briquettes on the cooling conveyor 8. Finally, the briquettes which have been cooled in this way are discharged by means of the cooling conveyors 8.
The fine particles which have been separated off by means of the screens 6 are returned and are once again subjected to briquetting. For this purpose, each screen 6 is connected to a hot bucket elevator 10 via a fines leg 9. Furthermore, the screen 6 is connected, via a further fines leg 11, to a cooling device which is provided as an alternative to the return device and which in the known plant is designed as a flight separator 12. To divide the fine particles between the fines legs 9 and fines legs 11, and therefore to the hot bucket elevator 10 or to the flight separator 12, a fines diverter (not shown in more detail) is provided.
The dividing of the fine particles for returning or, as an alternative to this, for cooling takes place on the basis of demand and available capacity.
In the known plant shown in Fig. 1, for each of the briquetting lines illustrated there is in each case one hot bucket elevator 10 for returning the fine particles and, as mentioned above, in each case one cooling conveyor 8 for cooling and discharging the briquettes.
Furthermore, there is a flight separator 12, which is fed by both briquetting lines. On account of the large number of individual units, the space taken up by the known plant is considerable.
By means of the hot bucket elevators 10, the fine particles are fed to the briquetting presses 4 or if appropriate - as is known from US-A-5,192,486 - to the storage hopper 1, each hot bucket elevator 10 being connected to each individual briquetting press 4 via in each case one breeches chute 10 and one fines leg 14.
To prevent reoxidation of the fine particles prior to briquetting, the hot bucket elevator 10 is provided with an inert gas system, which is not illustrated in more detail in Fig. 1. By applying inert gas to the hot bucket elevator 10, the fine particles are cooled, which then leads to increased wear to the briquetting presses 4. The hot bucket elevators 10 themselves are also exposed to high thermal and mechanical loads, on account of the small grain size of the fine particles and their high temperature. This leads to a high level of wear to the moving parts of the hot bucket elevators 10, particularly to the chain or the chain connecting elements, causing very high outlay on repair and maintenance.
The disadvantageously high levels of space taken up by the hot bucket elevators 10 in the known plant become clear in particular from Fig. 2, in accordance with which four briquetting lines are provided in parallel, each being fed with iron sponge in fine particle form from a storage hopper 1 via feed legs 3. In the illustration shown in Fig. 2, the briquetting presses 4 and the screens 6 of each of the four briquetting lines can be seen. Between each pair of briquetting lines, there is a hot bucket elevator 10 for returning the fine particles, the returned fine particles being fed back to the briquetting presses 4 via fines legs 14.
Furthermore, a cooling conveyor 8 for cooling and discharging the briquettes is provided for each pair of briquetting lines. A flight separator 12 is provided as the cooling device.
Taking into account the required angle of discharge for the fine particles conveyed through the fines legs 9 and 14, and also in view of the space taken up by the hot bucket elevators 10 themselves, a large overall height of the briquetting building is required for the known plant. When the fine particles are returned to the storage hopper 1, as is known from US-A-5,192,486, this height is even greater.
This large overall height, as well as the further drawbacks of a hot bucket elevator, in particular the high outlay on repair and maintenance, are avoided by means of the plant according to the invention.
Figs. 3 to 5 each provide a diagrammatic illustration of preferred embodiments of the plant according to the invention; components which are similar to those of the known plant are in each case provided with identical reference numerals to those used in Figs. l and 2.
Fig. 3 shows a reduction reactor 15, from which the metallic sponge in fine particle form is conveyed into the storage hopper 1 via a riser 16 by means of the reduction gas used for reduction. The riser 16 is in this case a section of pipe which has a refractory lining and through which the iron sponge in fine particle form is conveyed pneumatically upward by means of the reduction gas. The use of reduction gas as carrier gas in the riser 16 is beneficial, since on the one hand it is at the required pressure level and on the other hand it has a chemical composition which prevents immediate reoxidation of the hot iron sponge in fine particle form which has been discharged from the reduction reactor 15. The reduction gas is expanded in the storage hopper 1 and leaves the storage hopper 1 via the outlet line 2.
As described above in connection with Figs. 1 and 2, the iron sponge in fine particle form is fed to the briquetting presses 4 via fines legs 3. Two briquetting lines, each comprising a briquetting press 4, are illustrated in Fig. 3. These briquetting lines also comprise in each case one trommel 5, by means of which the briquette strands formed in the briquetting presses 4 are divided into individual briquettes. As an alternative to the trommels 5, it is also possible, for example, for impact crushers to be provided.
The fine particles which are produced during the briquetting and during the dividing of the briquette strands are then separated from the briquettes by means of the screen 6; in the exemplary embodiment illustrated, only a single screen 6 is provided for the two briquetting lines. This arrangement, which is more compact than that of the prior art and is therefore advantageous, is possible on account of the space saving design of the return device, which is explained in more detail below.
However, it would also be possible for a dedicated screen 6 to be provided for each briquetting line, or for the screen 6 to be fed by more than two briquetting lines. One advantage of the plant according to the invention is that, on account of the absence of hot bucket elevators 10, which take up large amounts of space, the briquetting region can overall be of highly flexible design.
The briquettes which are produced during the screening are cooled and discharged by means of the cooling conveyor 8, as described above. Via fines leg 9, the fine particles pass into a buffer container 17 arranged below the screen 6. As indicated by dashed line 9a in the exemplary embodiment shown in Fig. 3, the buffer container 17 is also fed by a further screen, which is not shown in more detail and belongs to two further briquetting lines, although it may also be fed, by way of example, by only a single screen.
The role of the buffer container 17 is to allow the fine particles to be released to the return device and/or to the cooling device 12 discontinuously or in batches. The dividing of the fine particles or the setting of the quantitative flow rates of fine particles fed to the return device and the cooling device 12 is carried out by means of slides 18. The buffer container 17 and the slides 18 allow the return or cooling system to be operated flexibly.
Alternatively, however, it is also possible, as is known from the prior art, to provide a fines diverter.
As explained in more detail above, the cooling device 12 may be designed as a flight separator or - according to a greatly simplified structure - as a trough, the trough being filled with water for the purpose of quenching the fine particles, and the cooled fine particles being removed from the trough by means of a wheel loader, for example.
In order to avoid or minimize cooling of the fine particles which are to be returned, the buffer container 17 is provided with a suitable thermal insulation (not shown in more detail).
From the buffer container 17, in accordance with Fig. 3 the fine particles pass into a charge container 19, which is likewise provided with thermal insulation, and, from this, to a pneumatic conveyor device. The charge container 19 can be filled with fine particles and emptied discontinuously and is connected to the riser 16 via a conveyor line 20.
In the conveyor line 20, the fine particles are exposed to a process gas which is supplied via a feed line 21 and are conveyed pneumatically into the riser 16. As an alternative to the process gas, it is also possible for a different gas, which is inert with respect to the fine particles and with respect to the hot iron sponge in particle form from the reduction reactor 15, to be used for the pneumatic conveying.
In the exemplary embodiment shown, the fine particles are conveyed out of the charge container 19 discontinuously, i.e. the fine particles are conveyed out of the charge container 19 only for limited periods. For this purpose, the charge container 19 is sealed with respect to the buffer container 17 and the riser 16 by means of the slide 18 and by means of a lock 22. Furthermore, the gas feed line 21 is also provided with a blocking member 22a.
The lock 22 and the slide 18 associated with the charge container 19 are provided with a control unit, which is designed to be locked by means of a blocking device, which is provided at the outlet for the metallic sponge in fine particle form from the reduction reactor 15 and comprises a ball valve 23 and a slide 24. The purpose of the locking is to avoid unfavorable pressure and flow conditions when the fine particles are being introduced into the riser 16.
In the exemplary embodiment shown in Fig. 3, the conveyor line 20 opens directly into the riser 16 and is kept very short, so that advantageously only very low pressure losses result.
The plant according to the invention is distinguished overall by a space-saving and flexible design. This results in considerable savings compared to the known return device with hot bucket elevators 10 simply in view of the number of units required. Furthermore, the return device itself is of significantly simpler design and therefore entails much lower investment, repair and maintenance costs.
The exemplary embodiment shown in Fig. 4 is similar to the exemplary embodiment shown in Fig. 3. However, the conveyor line 20 opens directly into the storage hopper 1, with the result that the operation of returning the fine particles takes place substantially independently of the operation of conveying the hot iron sponge in fine particle form through the riser 16.
The significant factor is that the fine particles are fed to the briquetting presses 4 together with the hot iron sponge in fine particle form from the reduction reactor 15. This optimizes the distribution of the returned fine particles in the overall flow of material, i.e. in the iron sponge in fine particle form, so that the returned fine particles are brought to an optimum briquetting temperature through contact with the hot iron sponge in fine particle form. In this way, the wear to the briquetting presses 4 caused by temperature fluctuations is minimized. Furthermore, the grain size for the returned material can be increased, so that the quantity of larger fine particles known as chips which cannot be returned can be minimized. The result is an increase in the effective discharge capacity of the briquetting, i.e. an increased output of briquettes.
In an illustration which is similar to that shown in Fig. 2, Fig. 5 provides a particularly clear illustration of the space-saving arrangement of four briquetting lines in a rectangular arrangement which is made possible by the use of the return device according to the invention. The return device itself is not shown in more detail in Fig. 5. Fig. 5 diagrammatically depicts the riser 16, which opens into the storage hopper 1. From the storage hopper 1, four feed legs 3 lead to the individual briquetting lines, the briquetting presses 4 in each case being illustrated diagrammatically in the figure. In the embodiment shown in Fig. 5, in each case one screen 6 is provided for in each case two briquetting lines which open out together. From the two screens 6, in each case one line 7 in turn leads to the single cooling conveyor 8. The return device is not, as in the prior art, arranged between the briquetting lines, so that the briquetting system can be of considerably more compact design. This leads to a lower overall height of the briquetting building and - in addition to the saving made with regard to the expensive hot bucket elevators themselves - to a further saving on installation parts, such as for example the saving made on a second cooling conveyor 8, with the result that the investment, repair and maintenance costs can be reduced substantially.
A plant for producing hot-briquetted iron sponge from hot iron sponge in fine particle form is described, for example, in US-A-5,192,486. According to US-A-5,192,486 oxide charge material is reduced in the solid state to iron by reduction gas using a direct reduction device.
To compress the reduced material so as to form a small surface for reoxidation, hot-briquetting is provided for the reduced material.
In the known plant, the iron sponge is compressed by means of a continuous pressing process using roller presses. The resulting briquette strand is then separated into individual briquettes by crushing in trommels or in impact crushers. The resulting quantity of fine particles, known as fines and chips, is returned to the briquetting presses after a screening operation, in order to save charge material. This takes place by means of hot bucket elevators at temperatures of 550-700°C under an inert atmosphere. The briquettes which are produced during the screening are discharged by means of cooling conveyors.
The fine particles and their very high temperature cause considerable wear to the moving parts of the hot bucket elevator, particularly to the chain or chain connecting elements, and therefore entail an extraordinarily high level of maintenance. A further drawback is the relatively large amount of space taken up by the return system as a whole, i.e. the hot bucket elevator including the supplying fines legs, which are understood as meaning downcomers for the material in fine particle form. This is because the hot bucket elevator is usually arranged between individual briquetting lines, thus increasing the space taken up between the briquetting lines. Therefore, taking into account the required angle of discharge for the fine particles conveyed by the fines legs, a larger overall height of the briquetting building is also required.
A hot bucket elevator can usually be fed from at most two briquetting lines, with the result that there is a correspondingly increased demand for hot bucket elevators if more than two briquetting lines are provided. In the known plant, a correspondingly larger number of discharge devices for the briquettes or, if, as well as the returning of the fine particles, cooling of the fine particles is alternatively provided, a correspondingly larger number of cooling devices, for example flight separators, is also required.
In the known plant, the returned material is also cooled by applying inert gas to the hot bucket elevator, which has an adverse effect on the briquetting performance and/or on the wear to the briquetting press, particularly if the fine particles are returned directly to the briquetting press. The investment, maintenance and repair costs are therefore very high for the known plant.
The present invention is based on the object of overcoming the drawbacks and difficulties of the known plant, in particular of minimizing the investment, repair and maintenance costs, and of simplifying processing of the fine particles. Furthermore, it is intended for it to be possible to reduce the height of the briquetting building and to reduce the construction outlay overall.
S According to the invention, this object is achieved by the fact that the return device is designed as a pneumatic conveyor device.
This results in a considerable saving on investment, repair and maintenance costs for the briquetting area.
Furthermore, space can be saved in the briquetting area. This is because, unlike a hot bucket elevator, the return device according to the invention does not have to be arranged between individual briquetting lines. Taking into account the space saving which is achieved according to the invention or the flexible configuration of the briquetting area, the height of the briquetting building can be reduced by 10 to 15%.
Furthermore, the number of separating devices for the fine particles, generally screens, can be optimized, i.e. it is possible to provide a screen for two or more briquetting lines. Consequently, it is also possible to reduce the number of cooling conveyors which are used to discharge the briquettes, and to feed a cooling conveyor from, for example, four briquetting lines.
In the plant according to the invention, the pneumatic conveyor device preferably opens out into a storage hopper connected upstream of the briquetting press.
According to a further preferred embodiment, the pneumatic conveyor device opens out into a feed line which guides the metallic sponge which is in fine particle form to the briquetting press and/or to the storage hopper.
The use of these measures improves the distribution of the returned fine particles in the overall stream of material, i.e. in the metallic sponge in fine particle form. The returned fine particles are brought to the optimum briquetting temperature through contact with hot metallic sponge in fine particle form. This results in the advantage of reduced wear to the briquetting tools. The grain size for the returned material can be increased, so that the quantity of relatively large fine particles, known as chips, which cannot be returned can be reduced or eliminated. This results in an increase in the effective discharge capacity of the briquetting, i.e. the output of briquettes.
Preferably, the feed line leading to the storage hopper is designed as a riser, the riser being connected downstream of at least one reduction reactor for the direct reduction of metal-oxide-containing material which is in fine particle form. In this context, the term riser is understood as meaning a substantially vertical section of pipe which has a refractory lining and through which the metallic sponge in fine particle form is conveyed pneumatically upward by means of the process gas of the reduction reactor. Via the riser, the returned fine particles, together with the hot metallic sponge in fine particle form, pass into the storage hopper, from where they are fed to one or more briquetting presses via feed legs. When the fine particles are being returned to the riser, the section of pipe of the pneumatic conveyor device required for this purpose can be kept very short.
Advantageously, a charge container for receiving the fine particles which have been separated off and are to be returned is connected upstream of the pneumatic conveyor device. Expediently, locks are provided for the purpose of blocking the charge container with respect to the separating device, on the one hand, and with respect to the briquetting press or the storage hopper or the feed. line leading to the briquetting press or to the storage hopper, on the other hand. As a result, the charge container is sealed with respect to the other components and may, for example, be fed with the fine particles and emptied discontinuously.
Advantageously, a control unit for the locks is provided, which control unit is designed to be locked by a blocking device provided at the outlet for the metallic sponge in fine particle form from the reduction reactor.
According to a preferred embodiment, a carrier gas used in the pneumatic conveyor device is process gas of a direct reduction device. This prevents reoxidation of the fine particles and, moreover, is approximately at the temperature of the fine particles. The process gas is advantageously also at the pressure prevailing in the reduction reactor.
According to a further preferred embodiment of the plant according to the invention, a device for cooling and then discharging a partial stream of the fine particles which have been separated out by means of the separating device is provided. The cooling device is preferably designed as a flight separator. The quantitative flow rate of fine particles supplied to the cooling device can be controlled by slides.
However, it is also possible to provide what is known as a fines diverter.
The plant according to the invention allows considerable simplification of the cooling device which is known per se, since only one delivery point for hot material is required. The result is savings in the area of the cooling device itself and in the area of the additional devices required, for example the fines diverter.
A highly simplified design, as an alternative cooling device, is a trough which is filled with water for quenching the fine particles and from which the cooled fine particles can be removed, for example by means of a wheel loader.
Preferably, downstream of the separating device there is a buffer container, from which lines lead to the return device and/or to the cooling device. This results in greater flexibility when splitting the fine particles into a partial stream to be returned and a further partial stream to be cooled and discharged.
Furthermore, the material to be returned can be delivered both to the return device and to the cooling device in each case discontinuously or in batches.
The return device and/or the buffer container is/are expediently thermally insulated, in order to minimize cooling of the fine particles which are to be returned.
In the plant according to the invention, a device for dividing a briquette strand which is formed in the briquetting press into individual briquettes, preferably a trommel and/or an impact crusher, is preferably connected downstream of the briquetting press. The briquette strand is separated into individual briquettes by means of the dividing device, producing the fine particles which are to be returned as well as the briquettes.
Preferably, in the plant according to the invention, a plurality of briquetting lines, each comprising a briquetting press and, if appropriate, a dividing device and a separating device, is provided, the briquetting lines opening out together to a single return device. It is particularly preferable for four briquetting lines to be provided, specifically in a rectangular arrangement as seen in plan view. Beneath the four briquetting lines or the associated separating device(s), by way of example a single buffer container is arranged, each individual separating device only being connected directly to the buffer container by one fines leg.
A process for producing hot-briquetted metallic sponge, in particular hot-briquetted iron sponge, from hot metallic sponge which is in the form of fine particles, in which process the metallic sponge is hot-briquetted by means of at least one briquetting press, then fine particles are separated from the briquettes formed in this way, in particular by screening, and the fine particles which have been separated off are returned to the briquetting press, is characterized in that the fine particles are returned by means of pneumatic conveying.
Preferably, the fine particles are returned to a storage hopper, which is connected upstream of the briquetting press, and/or to a feed line which guides the metallic sponge in fine particle form to the briquetting press and/or to the storage hopper.
Advantageously, the fine particles are returned continuously or discontinuously by means of a process gas from a direct reduction process.
A modified embodiment of the process according to the invention is characterized in that the fine particles are returned discontinuously by means of an individual conveyor container.
According to a further preferred embodiment, a partial stream of the fine particles which have been separated off is cooled and discharged.
According to yet another preferred embodiment, a briquette strand is formed by means of the briquetting press, and the briquette strand is divided into individual briquettes before the fine particles are separated off.
The briquetting of the metallic sponge which is in fine particle form and/or the dividing of the briquette strand into individual briquettes and/or the separating of the fine particles advantageously takes place in a plurality of briquetting lines, preferably in four briquetting lines, the returning of the fine particles which have been separated off taking place in a single return line.
The invention is explained in more detail below with reference to the drawing ( Figs . 1 to 5 ) , Figs . 1 and 2 each presenting a diagrammatic illustration of a plant which is known from the prior art and corresponds to a modified embodiment of the plant described in US-A-5,192,486, and Figures 3 to 5 each showing preferred embodiments of the invention.
In the known plant which is illustrated in Fig. 1, hot iron sponge which is in the form of fine particles and is conveyed out of a reduction reactor (not shown in more detail in Fig. 1) by means of a carrier gas, passes into a storage hopper 1. The carrier gas used for the iron sponge in fine particle form is reduction gas, which is then extracted from the storage hopper 1 via an outlet line 2.
From the storage hopper 1, the hot iron sponge which is in fine particle form passes via feed legs 3 into briquetting presses 4, two of which can be seen in Fig. 1. The briquetting presses 4 are arranged in parallel and are simultaneously fed with iron sponge in fine particle form from the storage hopper 1. In the known plant, however, it is also possible, for example, to provide four briquetting presses 4, as shown in Fig. 2.
The briquetting presses 4 are designed as roller presses, by means of which briquette strands are formed, which are divided into individual briquettes in _ g _ downstream trommels 5. In the plant shown in Fig. 1, each briquetting press 4 is assigned one trommel 5 for dividing the briquette strand.
During the briquetting itself and during the dividing of the briquette strand in the trommels 5, a considerable quantity of fine particles is produced, and these particles, if they were to be discharged in this form without further treatment, would be subject to high levels of reoxidation. To avoid such reoxidation, the fine particles are fed back for briguetting.
For this purpose, in the plant which is known from the prior art, the fine particles are separated from the briquettes by means of screens 6. In the known plants illustrated in Figs. 1 and 2, in each case one screen 6 is provided for in each case one briquetting press 4 and one trommel 5.
The briquettes pass via lines 7 to cooling conveyors 8;
in accordance with Fig. 1 a dedicated cooling conveyor 8 is provided for each briquetting line, comprising a briquetting press 4, a trommel 5 and a screen 6. As indicated by a dashed line in Fig. 1, lines 7a from two further briquetting lines, which are not shown in more detail in Fig. 1, also open out onto each cooling conveyor 8. In this case, one cooling conveyor 8 is provided for in each case two briquetting lines, as can be seen in particular from Fig. 2.
On the cooling conveyors 8, cooling gas passes around the briquettes as a result of the cooling gas being forced or sucked through a layer formed by the briquettes on the cooling conveyor 8. Finally, the briquettes which have been cooled in this way are discharged by means of the cooling conveyors 8.
The fine particles which have been separated off by means of the screens 6 are returned and are once again subjected to briquetting. For this purpose, each screen 6 is connected to a hot bucket elevator 10 via a fines leg 9. Furthermore, the screen 6 is connected, via a further fines leg 11, to a cooling device which is provided as an alternative to the return device and which in the known plant is designed as a flight separator 12. To divide the fine particles between the fines legs 9 and fines legs 11, and therefore to the hot bucket elevator 10 or to the flight separator 12, a fines diverter (not shown in more detail) is provided.
The dividing of the fine particles for returning or, as an alternative to this, for cooling takes place on the basis of demand and available capacity.
In the known plant shown in Fig. 1, for each of the briquetting lines illustrated there is in each case one hot bucket elevator 10 for returning the fine particles and, as mentioned above, in each case one cooling conveyor 8 for cooling and discharging the briquettes.
Furthermore, there is a flight separator 12, which is fed by both briquetting lines. On account of the large number of individual units, the space taken up by the known plant is considerable.
By means of the hot bucket elevators 10, the fine particles are fed to the briquetting presses 4 or if appropriate - as is known from US-A-5,192,486 - to the storage hopper 1, each hot bucket elevator 10 being connected to each individual briquetting press 4 via in each case one breeches chute 10 and one fines leg 14.
To prevent reoxidation of the fine particles prior to briquetting, the hot bucket elevator 10 is provided with an inert gas system, which is not illustrated in more detail in Fig. 1. By applying inert gas to the hot bucket elevator 10, the fine particles are cooled, which then leads to increased wear to the briquetting presses 4. The hot bucket elevators 10 themselves are also exposed to high thermal and mechanical loads, on account of the small grain size of the fine particles and their high temperature. This leads to a high level of wear to the moving parts of the hot bucket elevators 10, particularly to the chain or the chain connecting elements, causing very high outlay on repair and maintenance.
The disadvantageously high levels of space taken up by the hot bucket elevators 10 in the known plant become clear in particular from Fig. 2, in accordance with which four briquetting lines are provided in parallel, each being fed with iron sponge in fine particle form from a storage hopper 1 via feed legs 3. In the illustration shown in Fig. 2, the briquetting presses 4 and the screens 6 of each of the four briquetting lines can be seen. Between each pair of briquetting lines, there is a hot bucket elevator 10 for returning the fine particles, the returned fine particles being fed back to the briquetting presses 4 via fines legs 14.
Furthermore, a cooling conveyor 8 for cooling and discharging the briquettes is provided for each pair of briquetting lines. A flight separator 12 is provided as the cooling device.
Taking into account the required angle of discharge for the fine particles conveyed through the fines legs 9 and 14, and also in view of the space taken up by the hot bucket elevators 10 themselves, a large overall height of the briquetting building is required for the known plant. When the fine particles are returned to the storage hopper 1, as is known from US-A-5,192,486, this height is even greater.
This large overall height, as well as the further drawbacks of a hot bucket elevator, in particular the high outlay on repair and maintenance, are avoided by means of the plant according to the invention.
Figs. 3 to 5 each provide a diagrammatic illustration of preferred embodiments of the plant according to the invention; components which are similar to those of the known plant are in each case provided with identical reference numerals to those used in Figs. l and 2.
Fig. 3 shows a reduction reactor 15, from which the metallic sponge in fine particle form is conveyed into the storage hopper 1 via a riser 16 by means of the reduction gas used for reduction. The riser 16 is in this case a section of pipe which has a refractory lining and through which the iron sponge in fine particle form is conveyed pneumatically upward by means of the reduction gas. The use of reduction gas as carrier gas in the riser 16 is beneficial, since on the one hand it is at the required pressure level and on the other hand it has a chemical composition which prevents immediate reoxidation of the hot iron sponge in fine particle form which has been discharged from the reduction reactor 15. The reduction gas is expanded in the storage hopper 1 and leaves the storage hopper 1 via the outlet line 2.
As described above in connection with Figs. 1 and 2, the iron sponge in fine particle form is fed to the briquetting presses 4 via fines legs 3. Two briquetting lines, each comprising a briquetting press 4, are illustrated in Fig. 3. These briquetting lines also comprise in each case one trommel 5, by means of which the briquette strands formed in the briquetting presses 4 are divided into individual briquettes. As an alternative to the trommels 5, it is also possible, for example, for impact crushers to be provided.
The fine particles which are produced during the briquetting and during the dividing of the briquette strands are then separated from the briquettes by means of the screen 6; in the exemplary embodiment illustrated, only a single screen 6 is provided for the two briquetting lines. This arrangement, which is more compact than that of the prior art and is therefore advantageous, is possible on account of the space saving design of the return device, which is explained in more detail below.
However, it would also be possible for a dedicated screen 6 to be provided for each briquetting line, or for the screen 6 to be fed by more than two briquetting lines. One advantage of the plant according to the invention is that, on account of the absence of hot bucket elevators 10, which take up large amounts of space, the briquetting region can overall be of highly flexible design.
The briquettes which are produced during the screening are cooled and discharged by means of the cooling conveyor 8, as described above. Via fines leg 9, the fine particles pass into a buffer container 17 arranged below the screen 6. As indicated by dashed line 9a in the exemplary embodiment shown in Fig. 3, the buffer container 17 is also fed by a further screen, which is not shown in more detail and belongs to two further briquetting lines, although it may also be fed, by way of example, by only a single screen.
The role of the buffer container 17 is to allow the fine particles to be released to the return device and/or to the cooling device 12 discontinuously or in batches. The dividing of the fine particles or the setting of the quantitative flow rates of fine particles fed to the return device and the cooling device 12 is carried out by means of slides 18. The buffer container 17 and the slides 18 allow the return or cooling system to be operated flexibly.
Alternatively, however, it is also possible, as is known from the prior art, to provide a fines diverter.
As explained in more detail above, the cooling device 12 may be designed as a flight separator or - according to a greatly simplified structure - as a trough, the trough being filled with water for the purpose of quenching the fine particles, and the cooled fine particles being removed from the trough by means of a wheel loader, for example.
In order to avoid or minimize cooling of the fine particles which are to be returned, the buffer container 17 is provided with a suitable thermal insulation (not shown in more detail).
From the buffer container 17, in accordance with Fig. 3 the fine particles pass into a charge container 19, which is likewise provided with thermal insulation, and, from this, to a pneumatic conveyor device. The charge container 19 can be filled with fine particles and emptied discontinuously and is connected to the riser 16 via a conveyor line 20.
In the conveyor line 20, the fine particles are exposed to a process gas which is supplied via a feed line 21 and are conveyed pneumatically into the riser 16. As an alternative to the process gas, it is also possible for a different gas, which is inert with respect to the fine particles and with respect to the hot iron sponge in particle form from the reduction reactor 15, to be used for the pneumatic conveying.
In the exemplary embodiment shown, the fine particles are conveyed out of the charge container 19 discontinuously, i.e. the fine particles are conveyed out of the charge container 19 only for limited periods. For this purpose, the charge container 19 is sealed with respect to the buffer container 17 and the riser 16 by means of the slide 18 and by means of a lock 22. Furthermore, the gas feed line 21 is also provided with a blocking member 22a.
The lock 22 and the slide 18 associated with the charge container 19 are provided with a control unit, which is designed to be locked by means of a blocking device, which is provided at the outlet for the metallic sponge in fine particle form from the reduction reactor 15 and comprises a ball valve 23 and a slide 24. The purpose of the locking is to avoid unfavorable pressure and flow conditions when the fine particles are being introduced into the riser 16.
In the exemplary embodiment shown in Fig. 3, the conveyor line 20 opens directly into the riser 16 and is kept very short, so that advantageously only very low pressure losses result.
The plant according to the invention is distinguished overall by a space-saving and flexible design. This results in considerable savings compared to the known return device with hot bucket elevators 10 simply in view of the number of units required. Furthermore, the return device itself is of significantly simpler design and therefore entails much lower investment, repair and maintenance costs.
The exemplary embodiment shown in Fig. 4 is similar to the exemplary embodiment shown in Fig. 3. However, the conveyor line 20 opens directly into the storage hopper 1, with the result that the operation of returning the fine particles takes place substantially independently of the operation of conveying the hot iron sponge in fine particle form through the riser 16.
The significant factor is that the fine particles are fed to the briquetting presses 4 together with the hot iron sponge in fine particle form from the reduction reactor 15. This optimizes the distribution of the returned fine particles in the overall flow of material, i.e. in the iron sponge in fine particle form, so that the returned fine particles are brought to an optimum briquetting temperature through contact with the hot iron sponge in fine particle form. In this way, the wear to the briquetting presses 4 caused by temperature fluctuations is minimized. Furthermore, the grain size for the returned material can be increased, so that the quantity of larger fine particles known as chips which cannot be returned can be minimized. The result is an increase in the effective discharge capacity of the briquetting, i.e. an increased output of briquettes.
In an illustration which is similar to that shown in Fig. 2, Fig. 5 provides a particularly clear illustration of the space-saving arrangement of four briquetting lines in a rectangular arrangement which is made possible by the use of the return device according to the invention. The return device itself is not shown in more detail in Fig. 5. Fig. 5 diagrammatically depicts the riser 16, which opens into the storage hopper 1. From the storage hopper 1, four feed legs 3 lead to the individual briquetting lines, the briquetting presses 4 in each case being illustrated diagrammatically in the figure. In the embodiment shown in Fig. 5, in each case one screen 6 is provided for in each case two briquetting lines which open out together. From the two screens 6, in each case one line 7 in turn leads to the single cooling conveyor 8. The return device is not, as in the prior art, arranged between the briquetting lines, so that the briquetting system can be of considerably more compact design. This leads to a lower overall height of the briquetting building and - in addition to the saving made with regard to the expensive hot bucket elevators themselves - to a further saving on installation parts, such as for example the saving made on a second cooling conveyor 8, with the result that the investment, repair and maintenance costs can be reduced substantially.
Claims (18)
1. Plant for producing hot-briquetted metallic sponge, in particular hot-briquetted iron sponge, from hot metallic sponge which is in the form of fine particles, which plant comprises at least one briquetting press (4), a device (6) for separating fine particles from briquettes formed by means of the briquetting press (4), which device is connected downstream of the briquetting press (4), and a device for returning the fine particles which have been separated off to the briquetting press (4), characterized in that the return device is designed as a pneumatic conveyor device (20, 21) and a plurality of briquetting lines, each comprising a briquetting press (4) and, if appropriate, a dividing device (5) and, if appropriate, a separating device (6), is provided, the briquetting lines opening out together to a single return device (20, 21; 25).
2. Plant according to claim 1, characterized in that the pneumatic conveyor device (20, 21) opens out into a storage hopper (1) connected upstream of the briquetting press (4).
3. Plant according to claim 1 or 2, characterized in that the pneumatic conveyor device (20, 21) opens out into a feed line (16) which guides the metallic sponge which is in fine particle form to the briquetting press (4) and/or to the storage hopper (1).
4. Plant according to claim 3, characterized in that the feed line (16) leading to the briquetting press (4) and/or to the storage hopper (1) is designed as a riser, the riser being connected downstream of at least one reduction reactor (15) for the direct reduction of metal-oxide-containing material which is in fine particle form.
5. Plant according to one of claims 1 to 4, characterized in that a charge container (19) for receiving the fine particles which have been separated off and are to be returned is connected upstream of the pneumatic conveyor device (20, 21).
6. Plant according to claim 5, characterized in that locks (18, 22) are provided for the purpose of blocking the charge container (19) with respect to the separating device (6), on the one hand, and with respect to the briquetting press (4) or the storage hopper (1) or the feed line (16) leading to the briquetting press (4) or to the storage hopper (1), on the other hand.
7. Plant according to claim 6, characterized in that a control unit for the locks (18, 22) is provided, which control unit is designed to be locked by a blocking device (23, 24) provided at the outlet for the metallic sponge in fine particle form from the reduction reactor (15).
8. Plant according to one of claims 1 to 7, characterized in that a carrier gas which is used in the pneumatic conveyor device (20, 21) is process gas of a direct reduction device (15).
9. Plant according to one of claims 1 to 8, characterized in that a device (12) for cooling and then discharging a partial stream of the fine particles which have been separated out by means of the separating device (6) is provided.
10. Plant according to one of claims 1 to 9, characterized in that downstream of the separating device (6) there is a buffer container (17), from which lines lead to the return device (20, 21; 25) and/or to the cooling device (12).
11. Plant according to one of claims 1 to 10, characterized in that the return device (20, 21;
25) and/or the buffer container (17) is/are thermally insulated.
25) and/or the buffer container (17) is/are thermally insulated.
12. Plant according to one of claims 1 to 11, characterized in that a device (5) for dividing a briquette strand which is formed in the briquetting press (4) into individual briquettes, preferably a trommel and/or an impact crusher, is connected downstream of the briquetting press (4).
13. Plant according to one of claims 1 to 12, characterized in that at least four briquetting lines are provided in a rectangular arrangement, as seen in plan view.
14. Process for producing hot-briquetted metallic sponge, in particular hot-briquetted iron sponge, from hot metallic sponge which is in the form of fine particles, in which process the metallic sponge is hot-briquetted by means of at least one briquetting press (4), then fine particles are separated from the briquettes formed in this way, in particular by screening, and the fine particles which have been separated off are returned to the briquetting press (4), characterized in that the fine particles are returned by means of pneumatic conveying (20, 21), the briquetting of the hot metallic sponge which is in fine particle form and, if appropriate, the dividing of the briquette strand into individual briquettes and, if appropriate, the separating of the fine particles taking place in a plurality of briquetting lines, preferably in four briquetting lines, the returning of the fine particles which have been separated off taking place in a single return line.
15. Process according to claim 14, characterized in that the fine particles are returned to a storage hopper (1), which is connected upstream of the briquetting press (4), and/or to a feed line (16) which guides the metallic sponge in fine particle form to the briquetting press (4) and/or to the storage hopper (1).
16. Process according to one of claims 14 or 15, characterized in that the fine particles are returned continuously or discontinuously by means of a process gas from a direct reduction process.
17. Process according to one of claims 14 to 16, characterized in that a partial stream of the fine particles which have been separated off is cooled and discharged.
18. Process according to one of claims 14 to 17, characterized in that a briquette strand is formed by means of the briquetting press (4), and the briquette strand is divided into individual briquettes before the fine particles are separated off.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ATA477/99 | 1999-03-17 | ||
| AT0047799A AT407258B (en) | 1999-03-17 | 1999-03-17 | DEVICE FOR PRODUCING HOT BRIQUETTED METAL SPONGE, IN PARTICULAR HOT BRIQUETTED IRON SPONGE |
| PCT/EP2000/001128 WO2000055379A1 (en) | 1999-03-17 | 2000-02-11 | Device for producing hot-briquetted metallic sponge, especially hot-briquetted sponge iron |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2365982A1 true CA2365982A1 (en) | 2000-09-21 |
Family
ID=3491669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002365982A Abandoned CA2365982A1 (en) | 1999-03-17 | 2000-02-11 | Device for producing hot-briquetted metallic sponge, especially hot-briquetted sponge iron |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP1169484A1 (en) |
| JP (1) | JP2002539329A (en) |
| KR (2) | KR20020001777A (en) |
| AT (2) | AT407258B (en) |
| AU (1) | AU2548300A (en) |
| CA (1) | CA2365982A1 (en) |
| WO (1) | WO2000055379A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102014111906A1 (en) * | 2014-08-20 | 2016-02-25 | Maschinenfabrik Köppern Gmbh & Co. Kg | Plant for hot briquetting |
| CN112969745B (en) * | 2018-11-13 | 2022-09-30 | 帝斯曼知识产权资产管理有限公司 | Foaming composition |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5443286B2 (en) * | 1973-05-25 | 1979-12-19 | ||
| US4412858A (en) * | 1982-07-12 | 1983-11-01 | Hylsa, S.A. | Method of converting iron ore into molten iron |
| JPS6079798A (en) * | 1983-10-06 | 1985-05-07 | 三洋電機株式会社 | Resin circuit board |
| KR910008000B1 (en) * | 1989-08-01 | 1991-10-05 | 효성바스프 주식회사 | Specific gravity control method for prefoamed styrene particles |
| US5445363A (en) * | 1990-01-09 | 1995-08-29 | Hylsa S.A. De C.V. | Apparatus for the pneumatic transport of large iron-bearing particles |
| EP0515744B1 (en) * | 1991-05-30 | 1998-04-29 | HYLSA, S.A. de C.V. | Method for the transport of sponge iron |
| DE19545985A1 (en) * | 1995-12-09 | 1997-06-12 | Metallgesellschaft Ag | Process for hot briquetting of granular sponge iron |
-
1999
- 1999-03-17 AT AT0047799A patent/AT407258B/en not_active IP Right Cessation
-
2000
- 2000-02-11 AU AU25483/00A patent/AU2548300A/en not_active Abandoned
- 2000-02-11 CA CA002365982A patent/CA2365982A1/en not_active Abandoned
- 2000-02-11 JP JP2000605795A patent/JP2002539329A/en not_active Withdrawn
- 2000-02-11 WO PCT/EP2000/001128 patent/WO2000055379A1/en not_active Application Discontinuation
- 2000-02-11 EP EP00903688A patent/EP1169484A1/en not_active Withdrawn
- 2000-02-11 KR KR1020017011816A patent/KR20020001777A/en not_active Application Discontinuation
- 2000-07-06 AT AT00890212T patent/ATE251018T1/en active
- 2000-07-13 KR KR1020000040150A patent/KR100576954B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| EP1169484A1 (en) | 2002-01-09 |
| ATA47799A (en) | 2000-06-15 |
| KR20020001777A (en) | 2002-01-09 |
| AT407258B (en) | 2001-02-26 |
| AU2548300A (en) | 2000-10-04 |
| ATE251018T1 (en) | 2003-10-15 |
| JP2002539329A (en) | 2002-11-19 |
| KR20010049776A (en) | 2001-06-15 |
| WO2000055379A1 (en) | 2000-09-21 |
| KR100576954B1 (en) | 2006-05-10 |
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