Bulk material mill for processing coarse materials

Abstract

The invention relates to a method for processing a bulk material (8) in a processing plant (1), comprising: feeding the bulk material (8) into a grinding and separating device (2), the grinding and separating device (2) comprising a grinding device (5) in which the bulk material (8) is ground into a ground material (23) and a separating device (6) in which the bulk material (8) is separated from the ground material (23); the ground grinding material (23) is separated into a fine material (12) and a coarse material (13) in a separating device (6), and the fine material (12) is discharged from the grinding and separating device (2), at least part of the coarse material (13) is discharged from the grinding and separating device (2), the discharged part of the coarse material (13) comprises at least 65 mass% of the fed bulk material (8), and the discharged part of the coarse material (13) is fed for subsequent use. The invention further relates to a processing device (1) for processing bulk material (8) and to the use of a processing device (1) having a mill and a classifier for de-dusting ore.

Description

Technical Field

[0001] The invention relates to a method for processing bulk material in a processing plant, a processing plant for processing bulk material and the use of a processing plant having a mill and a classifier for dedusing ore. Background Art

[0002] Grinding devices and separation devices are common devices for grinding and processing raw materials. The incoming raw material is fed into the grinding device and crushed into different fractions, such as fractions with different particle sizes. The different particle sizes are then separated in the separation device. The fully finely ground fraction is discharged from the grinding and separation device in the form of fine material. The coarse fraction with too large particle size is rejected by the separation device and is usually fed back to the grinding device, where they are ground again and thus further crushed. This cycle is repeated until all the incoming raw material is finally discharged from the grinding and separation device in the form of fine material. Alternatively, a portion of the coarse material rejected by the separation device can be discharged and therefore no longer fed to the grinding device. Discharging difficult-to-grind materials can, for example, increase the productivity of the grinding and separation device. The discharged coarse material is usually dumped or fed back into the grinding device later. The discharged fine material has a sufficiently fine particle size required and is fed to subsequent use.

[0003] A method for processing a multiphase mineral raw material is known from EP 3 326 720 B1. The raw material fed to the mill is comminuted using grinding rollers. The ground raw material is then separated into fine material and coarse material in a classifier. The fine material is discharged from the device. Part of the coarse material discharged by the classifier is discharged from the mill. The remaining coarse material is fed back to the grinding rollers and further comminuted until it is finally discharged from the device in the form of fine material.

[0004] The methods known in the prior art have in common that the grinding material is crushed into the desired particle size and then the crushed grinding material is discharged from the device in the form of fine material. The discharge of undesirable substances or phases that are difficult to grind may occur in a certain section through the discharge of coarse material. However, the discharge particle size of the coarse material is difficult to control and adjust. Summary of the invention

[0005] In this application, particle size is understood to refer to the size of a single particle (also referred to as a particle). The term "particle" is used as a synonym for particle in this application. If the particle is a perfect sphere, the particle size will represent a measure of the diameter of each sphere. However, since particles are generally not perfectly spherical, but have different shapes, the particle size can be interpreted as an equivalent diameter.

[0006] The object of the invention is to effectively and precisely separate unwanted substances and particle sizes from the ground grinding material and discharge them from the processing plant. This object is achieved by a method for processing bulk material according to claim 1, a processing plant for processing bulk material according to claim 12 or the use of a processing plant for dust removal of ore according to claim 14.

[0007] The method for processing bulk material in a processing plant according to the invention comprises: feeding bulk material into a grinding and separation device; grinding the bulk material into a ground grinding material in the grinding device; separating the ground grinding material into a fine material and a coarse material in the separation device, discharging the fine material from the grinding and separation device, and discharging at least a portion of the coarse material from the grinding and separation device. The discharged portion of the coarse material discharged from the grinding and separation device accounts for at least 65% by mass of the fed bulk material. The discharged portion of the coarse material can be fed to subsequent use. The grinding and separation device comprises a grinding device and a separation device.

[0008] In technical terms, separation of the ground grinding material may also be referred to as classification, grading or sorting.

[0009] The discharged fines may be dumped or sent to a landfill or one or more separate further processing stages. For example, the fines may be sent to a separate fines processing stage. Alternatively or additionally, the fines may be used as filler.

[0010] The fed bulk material may have at least a first phase and a second phase. The coarse material may have a higher proportion of the first phase than the fed bulk material. The coarse material may have a higher proportion of the first phase than the fine material. The fine material may have a higher proportion of the second phase than the coarse material. The fine material may have a higher proportion of the second phase than the fed bulk material.

[0011] The fed bulk material may be a solid material with different phases. The fed bulk material may be a raw material with several mineral phases. The fed bulk material may be a composite material, such as concrete or composite plastic. The fed bulk material may be in one piece or in the form of several solids.

[0012] The first phase and the second phase may be firmly bound together in the bulk material.The first phase and the second phase may be loose in the bulk material.

[0013] The first phase and the second phase may have particles. The particles of the first phase may have a larger average particle size than the particles of the second phase. On average, the particles of the first phase may have a higher density than the particles of the second phase. On average, the particles of the first phase may have a larger particle size and a higher density than the particles of the second phase.

[0014] The first phase and the second phase may have different grindabilities. The second phase may have better grindability than the first phase. The second phase may be comminuted and / or comminuted into smaller particles, i.e. particles with a smaller particle size, faster. The second phase may be accumulated in the fine material by the separation device due to its particle size. The first phase may be enriched in the coarse material by the separation device due to its particle size.

[0015] The first phase may be of the same material as the second phase. The first phase may be composed of the same material as the second phase. The first phase and the second phase may be largely identical such that the only difference between them is the particle size.

[0016] The first phase may be of a different material than the second phase.

[0017] The maximum particle size of the particles in the fine material may be 0.1 mm, preferably 0.05 mm, preferably 0.01 mm, preferably 0.005 mm. The maximum particle size may represent only a theoretical threshold value. In practice, the separation of fine material and coarse material is also affected by other factors, such as the density and / or shape of the particles, so that particles with a particle size greater than the maximum particle size are sometimes enriched in the fine material. Therefore, the maximum particle size may represent a particle size threshold value, below which 90% by mass, in particular 95% by mass, preferably 99% by mass of the particles in the fine material are below.

[0018] The second phase may have a particle size that is not preferred for further processing, in particular a non-preferred particle size. Such non-preferred particle size or particle sizes may be discharged from the grinding and separation device as fines.

[0019] In the fed bulk material, the first phase can be arranged at least partially, in particular completely, within the second phase. In the fed bulk material, the second phase can be arranged partially, in particular completely, within the first phase. In the fed bulk material, the first phase can be arranged at least partially connected to the second phase.

[0020] The particles of the fed bulk material may consist of a first phase and a second phase. The fed bulk material may also have other phases. During grinding, the first phase and the second phase may at least partially detach from each other. During grinding, the first phase and the second phase may at least partially dissolve from each other and from the other phases. During grinding, the particles of the first phase and / or the particles of the second phase may be comminuted.

[0021] The discharged portion of coarse material can account for at least 70% by mass, in particular at least 75% by mass, in particular at least 85% by mass, preferably at least 95% by mass of the fed bulk material.

[0022] The discharged fines can account for a maximum of 35 mass %, in particular a maximum of 25 mass %, in particular a maximum of 15 mass %, preferably a maximum of 10 mass %, preferably a maximum of 5 mass % of the fed bulk material.

[0023] The discharged fines may constitute at least 1 mass %, in particular at least 2 mass %, in particular at least 3 mass %, in particular at least 5 mass %, in particular at least 10 mass % of the fed bulk material.

[0024] The grinding and separation device can have a grinding device and a separation device. The grinding device can be a mill, in particular a vertical mill. The separation device can be a classifier, in particular a rotary classifier. The grinding and separation device can be a mill-classifier combination.

[0025] In the separation device, separation into fine material and coarse material can take place. The fine material can be discharged from the grinding and separation device. The ground grinding material rejected by the separation device, the so-called coarse material, can be discharged separately from the grinding and separation device. Part of the coarse material rejected by the separation device can also be fed back into the grinding device.

[0026] The classifier, in particular the rotary classifier, can have an adjustable rotation speed. The classifier can be driven by a motor. The control unit can in particular continuously / steplessly control the motor and thus the rotation speed of the classifier.

[0027] The discharged fines may be controllable via the rotational speed of the classifier. The particle size distribution in the fines may be controllable or at least influenceable via the rotational speed of the classifier. The density distribution in the fines may be controllable or at least influenceable via the rotational speed of the classifier. The proportion of the fed bulk material discharged as fines may be controlled via the rotational speed of the classifier. The rotational speed of the classifier may be used to set a theoretical maximum value for the particle size of the fines. The rotational speed of the classifier may be used to set a theoretical maximum value for the density of the fines.

[0028] The coarse material discharged may be controllable via the rotation speed of the classifier. The particle size distribution in the coarse material may be controllable via the rotation speed of the classifier. The density distribution in the coarse material may be controllable via the rotation speed of the classifier. The proportion of the in-feed bulk material discharged as coarse material may be controllable via the rotation speed of the classifier. The rotation speed of the classifier may be used to set a theoretical minimum value for the particle size of the coarse material. The rotation speed of the classifier may be used to set a theoretical minimum value for the density of the coarse material.

[0029] The rotation speed of the classifier can be used to set a preferred threshold value for the particle size of the fine material. Those skilled in the art will appreciate that this particle size threshold value does not necessarily represent a strict limit of 100%. The discharged fine material is generally not only affected by its particle size, but also, for example, by its density and / or shape. Therefore, the adjustable preferred particle size threshold value can be interpreted as a percentile value. A large proportion of the discharged fine material, for example at least 90% by mass, preferably at least 95% by mass, preferably at least 99% by mass, may have a particle size less than or equal to the set preferred threshold value. A large proportion of the coarse material rejected by the classifier, for example at least 90% by mass, preferably at least 95% by mass, preferably at least 99% by mass, may have a particle size greater than the set preferred particle size limit.

[0030] The rotation speed of the classifier can be used to set a preferred threshold value for the density of the fine material. A person skilled in the art will appreciate that this density threshold value is not necessarily a strict limit of 100%, since the discharged fine material is not only affected by its density, but also, for example, by its particle size and / or shape. Therefore, the adjustable preferred density threshold value can be regarded as a quantile value. A large proportion of the discharged fine material, for example at least 90% by mass, preferably at least 95% by mass, preferably at least 99% by mass, may have a density less than or equal to the set preferred threshold value. A large proportion of the coarse material rejected by the classifier, for example at least 90% by mass, preferably at least 95% by mass, preferably at least 99% by mass, may have a density greater than the set preferred density threshold value.

[0031] The bulk material fed may consist essentially of ore, in particular metal ore, preferably iron ore. The bulk material fed may have an ore proportion of at least 10% by mass, preferably at least 30% by mass, preferably at least 50% by mass. The bulk material fed may have a metal proportion of at least 10% by mass, preferably at least 30% by mass, preferably at least 50% by mass. The bulk material fed may have an iron proportion of at least 10% by mass, preferably at least 30% by mass, preferably at least 50% by mass.

[0032] The metal content of the metal ore may be at least 0.1 mass %, preferably at least 1 mass %, preferably at least 5 mass % of the metal ore. The iron content of the iron ore may be at least 1 mass %, preferably at least 10 mass %, preferably at least 30 mass %, preferably at least 50 mass % of the iron ore.

[0033] The bulk material fed can consist mainly of concrete, in particular old concrete or recycled concrete. The bulk material fed can have a concrete proportion of at least 10% by mass, preferably at least 30% by mass, preferably at least 50% by mass.

[0034] Concrete fed as bulk material may contain cement stone, hydrated cement or setting cement and aggregate. Hereinafter, only the term cement stone is used as a representative of cement stone, hydrated cement and setting cement. Cement stone and aggregate may be separated from each other in a grinding device. The cement stone contained in the fed concrete may have a better grindability than the aggregate contained in the fed concrete. Most of the cement stone contained in the fed concrete may be discharged as fine material. Most of the aggregate contained in the fed concrete may be discharged as coarse material.

[0035] The method can be a method for ore processing, in particular metal ore processing, in particular iron ore processing. Metal ore can be a mixture of rock and metal. Metals can usually be present as metal compounds in metal ore. According to the present invention, the term metal compound also includes all sulfides and oxides. Iron ore can be a mixture of rock and iron. Iron can usually be present in iron ore as iron compounds.

[0036] The metal contained in the metal ore can be dissolved from the rock contained in the metal ore by a grinding device. The rock can have better grindability than the metal. After the grinding process, the rock can have a smaller average particle size than the metal. After the grinding process, the rock can be at least partially in the form of dust. Due to the smaller particle size, the rock can be selectively enriched in the fine material by the separation device and discharged as such. Due to the larger particle size, the metal can be selectively enriched in the coarse material and discharged as such. This selective enrichment can effectively and accurately separate the metal and the rock.

[0037] The iron contained in the iron ore can be separated from the rock contained in the iron ore by a grinding device. The rock may have better grindability than the iron. After the grinding process, the rock may have a smaller average particle size than the iron. After the grinding process, the rock may be at least partially in the form of dust. Due to the smaller particle size, the rock can be selectively enriched in the fine material by the separation device and discharged as such. Due to the larger particle size, the iron can be selectively enriched in the coarse material and discharged as such. This selective enrichment can allow the iron and rock to be effectively and accurately separated.

[0038] The process may be a method for processing old concrete or recycling concrete. In the following, only the term "old concrete" will be used as a representative term for old concrete or recycled concrete. The method may be a method for recycling old concrete. The method may be a method for processing and recycling old concrete. In recent years, the processing and recycling of raw materials, especially concrete, has become increasingly important due to ecological and economic reasons. Concrete may contain different aggregates, also called gravel or sand, which are firmly bound together by cement stone. The aggregates present in the concrete can be separated from the cement stone in a grinding device. The cement stone may have better grindability than the aggregate. After the grinding process, the cement stone may exist as cement stone dust. For the further use of the aggregate, it may be advantageous if the aggregate does not contain cement stone, especially cement stone dust. The cement stone dust can be enriched in the fine material by a separation device and thus separated from the aggregate. The aggregate can be enriched in the coarse material by a separation device.

[0039] The method may be a method for processing clay in connection with calcining of clay.The method may be a method for processing slag, in particular metallurgical slag.

[0040] The coarse material may be rejected by the separation device towards the grinding device. The coarse material may be directed from the separation device into a grit cone. The rejected coarse material may be conveyed to the grinding device. The grit cone may direct the rejected coarse material to the grinding device. The separation device may be arranged vertically above the grinding device. The rejected coarse material may be conveyed back to the grinding device by gravity.

[0041] The discharge of at least a portion of the coarse material from the grinding and separation device can take place between the separation device and the grinding device. The discharge of at least a portion of the coarse material from the grinding and separation device can take place via a screw conveyor. For example, the coarse material removed by the separation device can fall onto the screw conveyor due to gravity. The grit cone can guide at least a portion of the removed coarse material to the separation device, in particular the screw conveyor. The discharge of at least a portion of the coarse material from the grinding and separation device can take place via a chute. The discharge of at least a portion of the coarse material from the grinding and separation device can take place via a chute from which air is subsequently removed. The discharge of at least a portion of the coarse material from the grinding and separation device can take place via an air conveying channel. The discharge of at least a portion of the coarse material from the grinding and separation device can take place via an air conveying channel from which air is subsequently removed.

[0042] All coarse material rejected by the separation device can be discharged from the grinding and separation device.

[0043] The discharged coarse material can be fed to a second separation device. The second separation device can separate the discharged coarse material into at least two fractions, in particular at least three fractions, which have different particle sizes from each other. The second separation device can be, for example, a screening device or a second classifier.

[0044] During the processing of concrete, most of the cement paste contained in the fed concrete can be discharged as fine material. Most of the aggregate contained in the fed concrete can be discharged as coarse material and fed to the second separation device. The discharged aggregate can be separated into aggregates of different particle sizes in the second separation device. The discharged aggregate can be separated into sand and gravel, for example, in the second separation device.

[0045] The separation device can be arranged above the grinding device. The discharge of at least a portion of the coarse material can be carried out between the separation device and the grinding device.

[0046] The processing equipment for processing bulk materials according to the present invention comprises a grinding and separation device, a first discharge device and a second discharge device. The grinding and separation device may comprise a grinding device and a first separation device. The grinding device may be suitable for grinding the bulk material fed into the grinding and separation device into a ground grinding material. The first separation device may be suitable for separating the ground grinding material into fine material and coarse material. The first discharge device may be suitable for discharging fine material from the grinding and separation device. The second discharge device may be suitable for discharging at least a portion of the coarse material from the grinding and separation device. The processing equipment further comprises a second separation device. The second separation device may be suitable for separating the discharged coarse material into at least a first fraction and a second fraction. The particles in the first fraction may have an average particle size smaller than the particles in the second fraction. The second separation device may be suitable for separating the discharged coarse material into at least a first fraction, a second fraction and a third fraction. The second separation device may be suitable for separating the discharged coarse material into at least a first fraction, a second fraction, a third fraction and a fourth fraction. These fractions may have different average particle sizes.

[0047] Alternatively, the processing device may be adapted to operate without the second separation device. The processing device may have a control device adapted to control the processing device in such a way that the portion of coarse material discharged via the second discharge device is at least 65% by mass of the fed bulk material. The control may be a pure control or a feedback control may be performed based on the measured value. The measured value may indicate a relative amount or an absolute amount of the discharged portion of coarse material. For example, the measured value may reflect the mass flow of the discharged portion of coarse material.

[0048] The grinding and separation device can be a mill-classifier combination. The grinding device can be a mill, in particular a vertical mill. The mill can include a plurality of grinding rollers. The mill can include a grinding table.

[0049] The second separation device may be located directly downstream of the second discharge device. The first discharge device may be arranged higher than the first separation device. The first discharge device may be arranged vertically higher than the first separation device.

[0050] The ground material can be transported from the grinding device to the first separation device by means of a process gas stream, in particular heated air. The first discharge device can be an air duct. The fine material can be conveyed from the first discharge device to a filter or a cyclone separator, in particular by means of a process gas stream. In the filter or cyclone separator, the fine material can be filtered and collected from the process gas stream. The process gas stream can then be returned to the grinding and separation device.

[0051] The second discharge device may be a screw conveyor. The second discharge device may be a chute for removing air. The second discharge device may be an air channel for removing air. The second discharge device may be arranged between the first separation device and the grinding device. The second discharge device may be arranged vertically between the first separation device and the grinding device.

[0052] The second discharge device can be adapted to discharge at least 65 mass %, in particular at least 75 mass %, in particular at least 85 mass %, preferably at least 95 mass % of the fed bulk material as coarse material.

[0053] The first discharge device can be adapted to discharge a maximum of 35 mass-%, in particular a maximum of 25 mass-%, in particular a maximum of 15 mass-%, preferably a maximum of 5 mass-% of the fed bulk material as fines.

[0054] The first separating device may be a classifier, in particular a rotary classifier. The rotation speed of the classifier may be adjustable, in particular continuously / steplessly adjustable. The processing device may further comprise a motor. The separating device, in particular the classifier, may be driven by the motor.

[0055] The grinding and separating device may comprise a control unit. The control unit may be configured to control the proportion of fine material discharged via the first discharge device. The proportion of fine material may be specified relative to the bulk material fed. The control unit may be electrically connected to the motor. The control unit may be configured to adjust the rotation speed of the motor and thus the rotation speed of the classifier. The control unit may be configured to continuously / steplessly adjust the rotation speed of the motor and thus the rotation speed of the classifier. The rotation speed of the classifier may be used to adjust the proportion of fine material discharged. The rotation speed of the classifier may be used to adjust the theoretical maximum particle size in the fine material.

[0056] The second separation device may be a classifier. The second separation device may be a screening device. The second separation device may be adapted to separate the discharged coarse material into a first fraction and a second fraction. The second separation device may be adapted to separate the discharged coarse material into a first fraction, a second fraction and a third fraction. The second separation device may be adapted to separate the discharged coarse material into a first fraction, a second fraction, a third fraction and a fourth fraction. The fractions may have different average particle sizes from each other. The fractions may have different average densities relative to each other. The fractions may have different average particle sizes and densities relative to each other.

[0057] Another aspect of the invention comprises the use of a processing plant having a mill and a classifier for dedusting ore. The ore is discharged from the processing plant mainly as coarse material.

[0058] The classifier can be arranged above the mill. The above particularly means that the classifier is arranged vertically above the mill relative to the ground, in particular the earth's surface. The classifier can be arranged vertically centered above the mill. The classifier can be arranged above the mill, offset transversely to the vertical direction. In particular, the classifier is arranged above the grinding table of the mill. In particular, the classifier is arranged above the grinding rollers of the mill.

[0059] The classifier is in particular a rotary classifier. The classifier comprises an element which rotates around an axis, in particular a vertical axis.

[0060] Dust removal can be referred to as the removal of particles of small size, in particular undesirable small particle sizes. Finely ground dust can cause problems during further processing of the processed ore. Particles with a particle size of less than 0.02 mm, in particular less than 0.01 mm, can be referred to as dust.

[0061] Dust removal can be performed by discharging fine material. The particle size of the particles in the fine material can be controlled by the rotation speed of the classifier. The maximum particle size of the particles in the fine material can be controlled by the rotation speed of the classifier. Metal compounds are contained in ores, especially rocks. Ores, especially metal compounds and rocks, can be ground in a mill. The ground metal compounds can be mainly enriched in the coarse material. The ground stones can be mainly enriched in the fine material.

[0062] The ore may be a metal ore, in particular an iron ore. The ore is ground and comminuted in a mill. Metal compounds contained in the ore, in particular iron compounds, can be dissolved from the rock contained in the ore by the grinding process. The ground rock and metal compounds, in particular iron compounds, can be conveyed to a classifier and separated from each other to a large extent by the classifier. The ground rock can be mainly enriched in the fine material. The ground metal compounds, in particular iron compounds, can be mainly enriched in the coarse material. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In the following, advantageous embodiments of the invention are explained in more detail with reference to the accompanying drawings.

[0064] Figure 1 A schematic diagram of a processing plant for processing bulk material according to the invention is shown.

[0065] Figure 2 A vertical section through a processing plant according to the invention for processing bulk material is shown. DETAILED DESCRIPTION

[0066] Figure 1 A schematic diagram of a processing device 1 according to the invention is shown. The processing device 1 comprises a grinding and separating device 2, a first discharge device 3 and a second discharge device 4. The grinding and separating device 2 comprises a grinding device 5 and a first separation device 6.

[0067] The bulk material 8 stored in the silo 7 is conveyed to the material feed opening 11 of the grinding and separation device 2 via the conveyor belt 9 and the first rotary valve 10, and fed to the grinding device 5. After the grinding process, the bulk material 8 is conveyed to the first separation device 6 by the process gas flow. Figure 1 In the embodiment shown, the first separation device 6 is adapted to be a rotary classifier. The first separation device 6 separates the ground bulk material 8 into fine material 12 and coarse material 13.

[0068] The fine material 12 is discharged from the grinding and separation device 2 via the first discharge device 3 by means of the process gas flow and is conveyed to the filter 14. In the filter 14, the fine material 12 is separated from the process gas flow and collected. The fine material 12 collected in the filter 14 can be discharged from the filter 14 via the second rotary valve 15. A part of the filtered process gas flow is returned to the grinding and separation device 2 via the pipeline 16. The remaining process gas flow is discharged from the processing device 1 via the outlet 17.

[0069] The coarse material 13 is discharged from the grinding and separation device 2 via the second discharge device 4. Figure 1 In the embodiment shown, the second discharge device 4 is adapted to be in the form of a screw conveyor. The discharged coarse material 13 is conveyed to an intermediate storage 19 via a third rotary valve 18 .

[0070] From the intermediate storage 19 , the coarse material 13 can then be discharged from the processing plant 1 or fed to a second separation device 20 . Figure 1 The second separation device 20 shown in the figure is a screening device, and separates the coarse material 13 into four fractions B, C, D, E having different particle sizes. The fine material 12 discharged from the filter 14 is considered to be the first fraction A. Therefore, the second separation device 20 separates the coarse material 13 into the second fraction B, the third fraction C, the fourth fraction D, and the fifth fraction E.

[0071] Figure 2 A cross section of a processing device 1 according to the invention is shown. Basically, Figure 2 1 shows a grinding and separation device 2 of a processing plant 1. Bulk material 8 is fed into the grinding device 5 via a material feed opening 11. Figure 2 In the embodiment shown, the grinding device 5 comprises a grinding table 21 and a plurality of grinding rollers 22. The grinding rollers 22 crush the bulk material 8 into ground grinding material 23.

[0072] A process gas stream, for example air or hot gas, is introduced into the grinding and separation device 2 via an air inlet opening 24 in the lower region of the grinding device 5. The process gas stream conveys the sufficiently finely ground grinding material 23 to the first separation device 6. Figure 2 In the embodiment shown, the first separating device 6 is a rotary classifier. The first separating device 6 comprises an impeller 25 driven by a motor 26. The grinding and separating device 2 further comprises a control unit 27. The control unit 27 is electrically connected to the motor 26 and is adapted to control the motor 26 and thereby control the rotation speed of the impeller 25. The rotation speed of the impeller 25 is continuously / steplessly adjusted by the control unit 27 via the motor 26.

[0073] The sufficiently finely ground grinding material 23 is discharged from the first separation device 6 as fine material 12 via the first discharge device 3. The grinding and separation device further comprises a grit cone 28. The ground grinding material 23 that is not sufficiently finely ground, the so-called coarse material 13, is rejected by the separation device 6 in the direction of the grit cone 28. The grit cone 28 guides the coarse material 13 to the second discharge device 4. Figure 2 In the embodiment shown, the second discharge device 4 is adapted to be in the form of a screw conveyor. The coarse material 13 is discharged from the grinding and separating device 2 via the second discharge device 4. The discharged coarse material 13 is then fed to subsequent use.

Claims

1. A method for processing bulk material (8) in a processing plant (1), the method comprising: - feeding the bulk material (8) into a grinding and separation device (2), said grinding and separation device (2) comprising a grinding device (5) and a separation device (6), - grinding the bulk material (8) in the grinding device (5) to form ground grinding material (23), - separating the ground grinding material (23) into fine material (12) and coarse material (13) in the separation device (6), - discharging the fines (12) from the grinding and separation device (2), and - discharging at least part of the coarse material (13) from the grinding and separation device (2), and The discharged portion of the coarse material (13) accounts for at least 65% by mass of the fed bulk material (8).

2. The method for processing bulk materials according to claim 1, wherein: The fed bulk material (8) has at least a first phase and a second phase, wherein the coarse material (13) has a higher proportion of the first phase than the fed bulk material (8).

3. The method for processing bulk materials according to claim 2, wherein: The first phase and the second phase have particles, wherein the particles of the first phase have on average a larger particle size than the particles of the second phase and / or the particles of the first phase have on average a higher density than the particles of the second phase.

4. A method for processing bulk materials according to claim 2 or 3, wherein: The first phase has a different material than the second phase.

5. The method for processing bulk materials according to claim 1, wherein: The maximum particle size of the particles in the fine material (12) is 0.1 mm, preferably 0.05 mm, preferably 0.01 mm, preferably 0.005 mm.

6. The method for processing bulk material according to claim 1, wherein: The discharged portion of the coarse material (13) is at least 75% by mass, in particular at least 85% by mass, preferably at least 95% by mass, of the bulk material (8) fed in.

7. The method for processing bulk material according to claim 1, wherein: The separation device (6) is a classifier, in particular a rotary classifier.

8. The method for processing bulk materials according to claim 7, wherein: The particle size distribution in the coarse material (13) is controllable or at least influencable via the rotational speed of the classifier.

9. The method for processing bulk materials according to claim 1, wherein: The bulk material (8) consists essentially of ore, in particular metal ore, preferably iron ore.

10. The method for processing bulk material according to any one of claims 1 to 8, wherein: The bulk material (8) consists mainly of concrete, in particular old concrete or recycled concrete.

11. The method for processing bulk material according to claim 1, wherein: The separation device (6) is a first separation device (6), and the discharged coarse material (13) is supplied to a second separation device (20), wherein the second separation device (20) separates the discharged coarse material (13) into at least two fractions, in particular at least three fractions, in particular at least four fractions, which have different particle sizes and / or densities from each other.

12. A processing plant (1) for processing bulk material (8), the processing plant (1) comprising: a grinding and separation device (2), the grinding and separation device (2) comprising a grinding device (5) and a first separation device (6), wherein the grinding device (5) is suitable for grinding a fed bulk material (8) into a ground grinding material (23), and the first separation device (6) is suitable for separating the ground grinding material (23) into a fine material (12) and a coarse material (13); a first discharge device (3) for discharging the fine material (12) from the grinding and separation device (2); a second discharge device (4) for discharging the coarse material (13) from the grinding and separation device (2); control means adapted to control the processing device (1) so that the portion of the coarse material (13) discharged via the second discharge means (4) is at least 65% by mass of the bulk material (8) fed in; and A second separation device (20), wherein the second separation device (20) is suitable for separating the discharged coarse material (13) into at least a first fraction and a second fraction, wherein the particles in the first fraction have on average a smaller particle size and / or a lower density than the particles in the second fraction.

13. A processing plant for processing bulk materials according to claim 12, wherein: The grinding and separating device (2) comprises a control unit (27), wherein the control unit (27) is configured to control the proportion of fine material (12) discharged via the first discharge device (3).

14. Use of a processing plant (1) having a mill and a classifier for dust removal of ore, wherein: The classifier is arranged above the mill, and the ore is discharged from the processing plant (1) primarily as coarse material (8) via a discharge device (4) arranged between the classifier and the mill.

15. Use of a processing plant with a mill and a classifier for dust removal of ore according to claim 14, wherein: The dust removal is carried out by discharging fine material (12).

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