KR101908906B1 - Method and device for preparing and separating a material comprising a composite multi-substance system - Google Patents

Abstract

The present invention relates to a method for preparing and separating a material comprising a mixed multi-component system. Wherein the material is provided to the roller mill as a feed material. The in-bed actuation is effected by a grinding bed and a grinding roller in a roller mill, where the material is abraded by shear force and friction. The roller mill operates in such a way that the grinding bed has a minimum height which is higher than the diameter of one of the two components and the pressure of the roller is such that the contact pressure is 50 kN / To 140 kN / m < 2 >. Furthermore, the invention relates to a further developed vertical roller mill for carrying out the method according to the invention.

Description

METHOD AND APPARATUS FOR PREPARING AND SEPARATING A MATERIAL CONTAINING A BINARY MULTI-COMPONENT SYSTEM Abstract:

The present invention relates to a method for preparing and separating a material comprising a mixed multi-component system and a vertical roller mill for carrying out such a method.

In Germany, about 80 million tonnes of construction waste are produced annually. Most of these building wastes are concrete crushed concrete. Concrete and concrete slag are basically composed of grit, sand, and cement stone. Cement stones serve to bond the grit to the sand.

Preparing concrete slag by separating concrete slag into individual components is naturally particularly desirable in areas where grit and sand are absent. In particular, it is of interest to restore the used grit and / or sand. However, it is essential that grit and sand should be as completely refined as possible in relation to cement stone. Otherwise, the concrete produced in such a way will have a weak force when using the restored grit or sand to make concrete.

WO 2011/142663 A1 shows an example of a separating device to enable crushing of concrete slag and, if possible, restoration of the individual constituents of the concrete. However, with this device, the desired level of refinement of recycled discrete components such as grit and sand can not be reached or can only be reached under particularly advantageous conditions.

The basic feature of concrete recycling is that the grit is not particularly crushed during the preparation of concrete slag. Otherwise, this grit can only be used for low-grade concrete production.

Recently, roller mills, which are pure grinding instruments, have been used to prepare and sort materials.

Such a method is known, for example, as WO 2011/107124 A1. In the process disclosed herein, a stainless steel slag consisting of a silicate portion and a metal portion is crushed in an intended manner and these portions are separated from each other.

The critical hardness differences and density differences of the individual parts are used in the milling process to achieve separation. The basic feature of this method is that it continues to use the mill as a milling device to completely crush the raw materials supplied and to achieve the separation only as a secondary feature. Through grinding based on the required pressure, this method can be achieved in that one of the components to be separated is ductile and therefore not broken during the grinding process. In other words, separation occurs when one component is ground by the roller, while the other component is not ground. When the pressure during grinding is slightly too high, the constituents are not pulverized and an undesirable deformation is made.

However, this method can not be used for the preparation and classification of concrete slag because concrete slag is not ductile and all components or constituents of concrete slag will be crushed by the mill. Therefore, desirable results can not be achieved especially in the purification and recovery of grit.

It is an object of the present invention to provide a method and apparatus capable of preparing and separating a material comprising a mixed multi-component system in which the constituents are completely ductile.

This object is achieved by the present invention through a method for preparing and separating a material comprising a mixed multi-component system having the features of claim 1 and a vertical roller mill having the features of claim 13.

Advantageous embodiments of the invention are set forth in the description and the sub-claims.

According to the method of the present invention for preparing and separating a mixed multi-component system that includes at least a first component and a second component attached to the first component and the two components do not have ductility, Is fed to a roller mill having a grinding pan and a grinding roller for in-bed attrition as a material.

During the process, a grinding bed of the treated material and the material to be treated is formed on the grinding pan and the grinding roller is rotated on the grinding bed. During in-bed attrition, the grinding rollers in the grinding bed cause the shear force and the friction between the particles of the constituents to cause the material to contact the first and second components And particles of the first constituent, particles of the second constituent, and particles of the same constituent are mutually abraded.

In order to enable in-bed attrition in the roller mill, the roller mill must have a contact pressure to the vertically projected area of the average roller diameter ) Is in the range of 15 kN / m < 2 > to a maximum of 140 kN / m < 2 > Thus, the pressure is selected such that the pulverization of the first and / or second components based on pressure is basically not generated directly using the contact pressure. In other words, the preparation of the material is basically made only through wear between the material and particles of the first and / or second component. Pressure based grinding is not provided. As far as milling is concerned, this is mainly achieved through friction between the materials.

Moreover, the roller mill is operated in such a way that the grinding bed has a minimum height greater than the diameter of one of the two constituents. Following in-bed actuation and treatment in the grinding bed, at least the first and second components are removed from the processing circuit of the roller mill and sorted.

According to the invention, the core idea of the process is that the roller mill, in particular the vertical roller mill, is used to ensure that the material to be milled is "pressed" through the pressure of the roller and is no longer used as a milling tool, This is in particular the fact that the grinding bed formed in the roller mill is used for its constituent parts, in particular for the separation and preparation of the feed material into the first and second constituents. The separation and preparation of the feedstock is made in the grinding bed by mutual frictional forces (i.e., wear of the material).

According to the present invention, through the formation of a grinding bed with extremely low compressive force using rollers in a grinding bed, the attrition process or the abrasion process can be performed between individual components of the material including the mixed multi- Occurs or becomes possible.

With the in-bed assignment according to the present invention, it is also possible to separate a multi-material system in which the components are not ductile at all using a roller mill. It is also possible to separate multi-material systems consisting of fragile components. In other words, the grinding does not basically occur in the mill, and the pressure of the roller is diminished so that it is no longer possible for the milling through the roller or the roller to directly affect the grinding bed. The separation of the constituents of the multi-material system and the concomitant partial grinding are achieved mainly in the process of ablation or wear occurring in the grinding bed.

Within the scope of the present invention, attrition or abrasion can be understood to be the separation or purification of many components from adhesion between materials through rubbing or friction between the materials. Separation of constituents occurs, inter alia, through shear forces, which are generated by component rubbing against one another and lead to the purification of the individual constituents at the surface.

A further core idea forming the basis of the present invention is to form the grinding bed in such a way that the grinding bed has a minimum height greater than the diameter of one of the two constituent components. In particular, the harder and tougher components of the two components of the mixed multi-component system are selected. This is ensured through the design of a grinding bed whose harder components are not crushed by roller pressure. For this reason, it is not necessarily the hardest of the constituents. For example, it can also be advantageous that the height of the grinding bed is at least as high as the average size of one of the constituents. In this way it can be ensured in the preparation process that the preparation and grinding through the pulsation of the grinding bed (i.e., wear-based grinding), rather than the pressure-based grinding, is done with sufficient probability.

According to the intentions of the present invention, a mixed multi-component system may also be composed of more than two components described herein by way of example. The more cohesive component can be understood as a harder component according to the intention of the present invention.

The preferred pressure of the roller (which may be described as the grinding roller) is selected such that the contact pressure can be in the range of from 15 kN / m 2 up to 140 kN / m 2. The pressure is dependent on the size of the roller, the size of the vertical mill, and / or the weight of the roller. The contact pressure is therefore used as a reference value and there is a guide parameter that is independent of the dimensions of the roller or mill. The range of contact pressure is dependent on the material being treated and its range is chosen so that no pressure-based grinding of the grinding material occurs. When processing natural multi-material systems, undesirable pressure pulverization or unsuccessful processes can not be completely ruled out in a small part because there are a variety of different intensities in the entire range of multi-material systems.

The present invention is further based on the surprising discovery that it is possible to process the feed material in spite of a much lower contact pressure than the pressure for the operation of the roller mill. This basically means that the actual grinding no longer occurs in contrast to the operating mode of the wheat so far and instead the materials are not treated with each other and processed by the rollers. This makes it possible according to the invention to prepare and separate materials made up of components which are not even different in density at all.

The pressure is advantageously chosen such that the shear force between the particles generated during the in-bed actuation can range from 5 kN / m 2 to 70 kN / m 2, in particular from 7 kN / m 2 to 20 kN / m 2. The stated range of intergranular shear forces of the other components of the mixed multi-component system allows for good wear in the grinding bed and so preparation and separation of the mixed multi-component can be done in the mill.

Here, the presence of a shear force allows a sufficiently good purification between the individual constituents to be made without risking too much crushing.

The basic factor in adjusting the shear force is the pressure of the roller. This should ideally be set so that the desired shearing force is produced by the grinding plate rotating with the rotation of the rollers and rollers. In other words, different shear forces or frictional forces act on the material to be treated. One is shear force and frictional force between individual material particles and the other is shear force which is transmitted to material through roller.

Usually, when using the roller mill as a milling apparatus, the rollers are set to rotate in the grinding bed. Therefore, in a basic state, the peripheral speed of the roller can be assumed to be similar to the relative speed of the grinding bed located at the top of the rotating grinding plate. However, if the roller rotates at a slower speed than the grinding plate or the grinding bed, the speed difference at the contact surface results in a shear force that can be used in the in-bed actuation according to the present invention.

More specifically, the generation of the shear force is basically based on the velocity of the particles introduced along the bottom of the mill and the peripheral velocity of the sweeping or sweeping particles by the particles, as opposed to that.

In contrast to the basic operating mode when grinding with a roller mill, the method of the present invention requires a sufficiently high height of the grinding bed. For the method according to the present invention, it is preferred that the grinding bed has a maximum height of 8% of the diameter of the grinding fan and a maximum height of about 4%. In the mode of operation of a typical roller mill, the grinding material is actively crushed or broken by rollers. It is desirable that the grinding gap (i.e., the distance between the grinding roller and the grinding plate or the grinding fan) is not too wide. Whereby the pressure exerted on the grinding bed by the grinding roller can be actively used to grind the grinding material. If the grinding gap is too wide, on the one hand the grinding material may only be partially pulverized and the grinding material may not be subjected to an appropriate pressure, while on the other hand the grinding material may fall out of the grinding gap and exit without grinding.

In contrast, according to the present invention, it is desirable that the components of the particle or multi-material system are worn out in the grinding bed in response to the mode of operation. Therefore, the grinding bed height is preferably higher than that of the roller mill used exclusively for grinding purposes. The higher the height of the grinding bed, the more the relative motion of the particles or components in the grinding bed between them, and thus the in-bed orientation can be achieved.

In principle, the grinding bed height can be adjusted by the pressure of the roller, the feed material flow, the speed of the grinding fan, the height of the retention rim of the grinding fan and / or the internal circulation flow.

An increase in the pressure of the grinding roller reduces the grinding bed height through an increase in the associated contact pressure. The increase in feed material flow (i.e., if more grinding material per hour is supplied to the roller mill as feed material) increases the grinding bed height. In contrast, the high speed of the grinding pan ultimately reduces the height of the grinding bed, since the removal of the existing grinding material from the grinding pan occurs more quickly. The retention rim of the grinding pan is located at the edge of the grinding pan and is used to reduce or prevent the grinding material beyond the edge of the fan. If the height of the retention rim increases, the height of the grinding bed will also increase.

An additional parameter that can be used to adjust the grinding bed height is the internal circulating flow. In the case of a roller mill integrated with a sorter, in particular, there is a question of the amount of particles that are rejected in the classification and recirculated to the grinding pan for further processing. If the internal circulation flow increases, the grinding bed height also increases. The internal circulating flow can be influenced not only by the sorter setting, but also by the amount of process air flow.

For example, it has been proven advantageous to increase the pressure in order to achieve the force required for in-bed actuation in spite of the stronger material combination, in the event that the material coupling of the multi-material system becomes stronger. However, since the height of the grinding bed must ideally be constant, other parameters must be adjusted as the height of the grinding bed initially decreases due to the increased pressure. Here it is preferred to increase the flow of the feed material and / or the internal circulation flow. Alternatively or additionally, the speed of the grinding fan can also be reduced. Since the setting of these variables is possible while the process is in progress, for example, if the combination of multi-material systems is stronger than in the past during the test, it can be addressed through the variables mentioned here.

An additional possibility is to increase the height of the retention rim. However, this is not possible or complicated during the process. Therefore, this parameter is mainly used only when the roller mill used is intended to be replaced or designed for other multi-material systems.

If the material combination of the multi-material system decreases, the pressure will decrease correspondingly, thereby increasing the grinding bed in principle. As a reaction to this, the previously mentioned variables can now be adjusted in the opposite direction.

In principle, it is desirable to treat as high a throughput as possible during operation of the roller mill (i.e., as much feed material as possible per hour). If the flow rate is increased to increase the throughput, it is advantageous to increase the speed of the grinding fan to keep the grinding bed height constant. An increase in roller pressure will certainly reduce the grinding bed height, but this can lead to changes in in-bed ablation parameters. In particular, through the high pressure of the roller, the grinding pressure (i.e., the force to be applied to the grinding bed by the roller) will increase and the contact pressure will also increase. This causes insufficient preparation and separation of multi-material systems. Thus, if the feed material flow increases, it is preferred that the compensation be made only by an increase in the grinding fan speed. The same can be done if the internal circulation flow is increased to a great extent. An example is the case where a high degree of grinding of the material is required and therefore less material is removed through the sorbent as a powder. As previously mentioned, more material will be fed back to the grinding plate and in a similar manner will lead to an increase in feed material flow and an increase in the grinding bed height. At this time it is basically preferred to adjust through the application of the speed of the grinding fan only - in particular, increase - so that the grinding bed height is kept constant.

Various types of roller mills are known. In some roller mills the rollers are driven directly. In other roller mills, particularly in the LEOSHE type, the rollers are not driven by themselves, but instead are set to rotate through the frictional forces generated between the rollers and the grinding bed. In a normal mode of operation of a roller mill in which the roller mill is used for grinding, there is nothing relatively troublesome. However, it has been confirmed that in the case of using a roller mill for in-bed induction, more attention must be paid to the rotation of the grinding roller due to the extremely low pressure of the grinding rollers.

For this reason, it is preferred that the roller mill is initially operated at a pressure higher than the selected pressure when the roller mill is operating. This is necessary in order to place the rollers having a starting torque which must be overcome in the beginning in a rotating state. As a result, during the in-bed deposition process, friction between the grinding bed and the grinding rollers is sufficient in most cases to maintain the rotation of the rollers.

For this reason, the rotation of the roller is monitored during operation, and if it is determined that the rotation of the roller is too slow, it is preferred that the pressure of the roller increases with time. Insufficient rotation of the rollers changes the shear force applied by the rollers to the grinding bed and thus changes the quality of the in-bed motion. It is possible to check whether the roller has sufficient rotation or sufficient angular momentum by a short time increase of the roller pressure. According to the intention of the present invention, insufficient rotation of the rollers means that the peripheral speed of the roller is lower than 50% of the speed of the material flow under the roller. It can be assumed that the material flow under the rollers corresponds to the speed of the grinding plate below the grinding pan or roller. Depending on the material, a few percent can be added to better estimate the speed.

It is advantageous to design roller bearings to play a greater role in the general case, especially for setting the rotation of the grinding roller, in order to start the roller mill with only the low pressure recognized for in-bed actuation. This reduces the risk of reducing the starting torque on the one hand and, on the other hand, the additional stopping or grinding roller having a too low rotational speed.

According to a preferred embodiment, the roller mill operates in an over-running and / or air stream mode. In an operating mode of pure over-running mill, the prepared grinding material is transferred beyond the retention rim through rotation of the grinding pan and falls into the space below the grinding pan. This can be moved from here to another. In the air stream operating mode, the grinding material that has fallen beyond the grinding plate is moved up and away by the process air stream. On the grinding pan, the grinder is located in most cases and the grinding material prepared via the process air stream is transferred to the sorter. The classification occurs in the sorter and the grinding material which has been sufficiently purified and prepared is discharged from the preparation process, while the grinding material requiring additional processing is re-supplied (so-called rejection) to the preparation process.

 In the present invention, an in-bed transition can be regarded as having a little relation to the standard grinding process and is also described as a grinding process, which is different from other grinding techniques. However, the in-bed actuation is carried out by the roller mill and in practice does not result in additional grinding, but for easy understanding the term mill will apply. In the combined over-running and air stream mode, only a portion, but not all, of the overrunning grinding material is lifted up through a process air stream that sweeps around the grinding pan. The remaining part falls downward and is moved under the grinding pan by conveying means.

According to a preferred embodiment, the material to be prepared and separated comprising a mixed multi-component system is a concrete slab. The concrete slag itself is mostly composed of grit, sand, and cement stone. According to the present invention, the method allows the grit and sand to be separated from each other and from the cement stone and purified by in-bed actuation. Through the in-bed actuation, in particular the grit and the sand are separated from the cement stone by rubbing and after the method according to the invention the grit and the sand are once again They exist in pure form and can therefore be reused for concrete production.

In another advantageous embodiment of the invention, a vertical roller mill with a sorter or integrated with a sorter is used. In addition, the process air stream may comprise a mixture of at least a portion of the first and second components, such as, for example, cement stone and cement stone and sand, from the over-running grinding material, While the first refined component, such as grit and sand, is set as a coarse material so that it can be removed in the grinding process.

At least a portion of the ground second component, such as a ground cement stone, is refined in a grinding process and removed from the sorbent, and the first and second components, such as, for example, a mixture of cement stone and cement stone and sand, As well as insufficiently comminuted particles of the second component are rejected by the sorter and re-fed into the grinding pan. Additionally, the sand can be separated from the coarse material removed by the screen to enable additional separation in the case of a multi-material system comprising two or more components.

According to an advantageous embodiment, the vertical roller mill operates in a combined mode of over-running and air stream. The process air stream that sweeps from the bottom of the periphery of the grinding pan is set to move the adherence of light or small material, especially crushed cement stone, cement stone and sand, upwards of the sorter. A refined heavy component such as a sand and a grit is dropped down against the process stream and discharged as a coarse material in the grinding process. In addition, mixtures of components such as grit, sand, and cement stone can be released in the grinding process as coarse material. The yet insufficiently prepared material can be detected by the sorting process and re-fed to the in-bed emulsion according to the invention.

In order to separate the grit and the sand, it is appropriate that a subsequent separation be made by the screen. The material moved to the sorter by the process air stream is classified there. Depending on the setting of the sorter, for example, only the cement stone crushed in the fine powder is released and the remaining material is fed back to the grinding pan. The crushing of the cement stone is performed according to the above-described method according to the present invention by an in-bed impulse, not by a compressive force. In other words, cement stone is worn by other particles and other cement stones. It is possible to remove cement stones from sand and grit without grinding of sand or grit through such wear.

The method according to the invention is carried out by means of a rotatable grinding pan and at least two fixed rotatable grinding rollers which are rotated above the grinding material during the process in which a grinding bed of grinding material is formed during the process on top of said grinding fan. In this case, the classifier is preferably provided above the grinding roller, and may additionally be provided with a method of forming and maintaining a minimum grinding gap between the grinding fan and the grinding roller.

The vertical roller mill according to the present invention may be used in a variety of applications, for example, in the recognition that a significantly lower compression of the grinding material in the grinding bed is required than in a conventional grinding bed present for coal grinding, . However, there may be a problem with this low compression or pressure effect by the rollers, because the strength and additional properties of the grinding bed are distinctly different in each region. For example, due to the low compression and relatively high grinding bed height, the same point can contain more air than the other parts. If the grinding roller is operated at a constant pressure, there is a risk that the grinding roller will compress the grinding bed more than the other part at the part where more air is contained. The grinding roller can be influenced even through the grinding fan. All these variables and phenomena lead to a smooth operation of the grinding roller. This leads to vibration in the overall operation of the vertical mill, which is undesirable and even damaging. For example, if too much vibration occurs, the preparation process of the vertical roller mill must be stopped.

For this reason, it is recognized in the present invention that it is necessary to first provide a method of forming and maintaining a minimum grinding gap between the grinding roller and the grinding roller in the vertical mill. This method ensures that the grinding roller affects the grinding pan by other characteristics of the grinding bed.

Various possibilities for implementing the above method can be devised. For example, in an advantageous embodiment a corresponding stop or stop buffer may be provided in the grinding roller. Another possibility is to have a hydraulic system corresponding to the grinding roller.

According to a preferred embodiment, the hydraulic system is provided for adjusting the pressure of the grinding roller during the process. The hydraulic system supports the weight of the grinding roller so that the contact pressure in the range of 15 kN / m < 2 > to a maximum of 140 kN / m < 2 > acts on the vertically projecting portion of the mean roller diameter. Generally, the hydraulic system provided in a vertical roller mill (especially a LOESCHE type) is designed such that the pressure of the grinding roller acts in the same direction as the weight of the roller. Normally, according to the hydraulic system, a contact pressure of 600 kN / m 2 to 1000 kN / m 2 occurs. However, this is not desirable for in-bed assignments.

Because of the size of the grinding rollers in other mill systems and their weight up to 45 t, an inverse hydraulic system needs to be provided to reduce the weight of the grinding roller that compresses the grinding bed. The already known hydraulic system used to pivot out the grinding roller reduces the pressure acting on the grinding bed of the grinding roller but can not be used here because it can not keep the pressure at a constant level. Instead, it can be designed only for swift pivoting-out of the grinding roller, for example, in order to achieve the retention purpose.

According to an advantageous embodiment, a monitoring system is provided in each grinding roller and monitors the rotation of the grinding roller during the process. As already mentioned, monitoring is required when using a vertical roller mill for in-bed deposition, since the process proceeds at very low pressures, which means that the grinding roller may not rotate sufficiently. With the method of having a monitoring system, such a condition is detected and appropriate countermeasures, for example, temporarily increase the pressure.

According to the method and apparatus of the present invention, it is possible to prepare and separate materials comprising a mixed multi-component system in which the constituents are non-ductile.

1 shows a flow diagram of concrete preparation according to the present invention.
Figure 2 shows a cross-sectional view of a vertical roller mill.
Figure 3 shows a cut-out of the vertical roller mill of Figure 2;

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail by way of example of a diagrammatic embodiment according to the reference of the drawings.

FIG. 1 is an illustration of a method for preparing and separating materials with a mixed multi-component system of the present invention, and shows a flowchart 10 of a concrete crushing preparation. The method of preparation of concrete slabs described in more detail below can be used in the same or similar manner in other material systems where the individual constituents do not have ductility. The following design is merely an example to illustrate the precise implementation of the method according to the invention and its advantages through an example. In this example, the steps of the individual methods described with respect to each other can be performed separately, and thus each can be separately considered as part of the present invention.

Generally, the concrete is produced from 0 to 63 mm of concrete from the crushed stone by crushing and separating by hardened steel. Subsequently, classification into grit and sand portions usually occurs. However, these parts are still attached so that the cement stone can not be ignored. Therefore, the use of recycled grit and sand, up to 15% as aggregate in concrete products as a substitute for primary grit and sand, is considered technically justified.

This limit of up to 15% of the recycled material as a substitute for grit and sand can be clearly raised by the method according to the invention.

For this purpose, a concrete powder having a grain size of, for example, up to 80 mm is used as starting material or feed material 11. The concrete powder, also described as a concrete slag, is fed to the roller mill 12 as a feed material in accordance with the present invention. Roller mill 12 is operated in a manner in accordance with Figure 1 of combined over-running and air stream mode and is also described as a vertical roller mill. The process in the roller mill 12 and the mode of operation of the roller mill 12 will be described in more detail below with reference to FIG.

In accordance with the present invention, the roller mill 12 operates as an in-bed attrition rather than a milling unit. The prepared and ground cement stone 16 is therefore provided in the roller mill 12 and can in principle be removed from the preparation circuit in a sorter provided downstream of the roller mill 12.

In a manner of over-running, the coarse material 13 is removed from the preparation of the roller mill 12. The coarse material 13 is basically composed of grit, sand, and an adhesive material prepared, but the ratio is certainly smaller than that of the feed material 11. The material with adhesive can be in particular grit and / or sand with cement stones. Subsequently, the coarse material 13 is applied to the screen 14, where the sand 17, which is a part of 0 mm to 2 mm, can be removed. Through the method according to the invention, the sand 17 is well refined and can be used similar to the initial (primary) sand in the concrete product.

The coarse material 13 having a size of 2 mm or more is then introduced into the density classifying means 15. This allows the refined grit 18 with a higher density to be released from the process circuit. A material which does not have a sufficiently high density - grit and / or sand - where the adherent of the cement stone still exists - is fed back to the in-bed presence of the roller mill 12.

In addition, as a method which is not described here but which can be considered, the sand may also be introduced into the density sorting means to separate the deposits of cementitious or other impurities that are still present and re-supply them to the grinding mill Do.

Thus, according to the present invention, the method 10 separates the concrete crushing, in particular the concrete powder 11, the grit 18 and the sand 17 into high purity, It is possible to use it similar to a sand. It is therefore possible to achieve a much higher ratio than the 15% recycling rate that has been possible so far.

The density classification may be realized, for example, by dry density sorting by means of wind classifiers, air jigs and / or air-fluidised bed sorting . Alternatively, wet density sorting may be used. However, the material fed back to the roller mill 12 must be dried again. Possible wet density classification methods include fluidized bed sorting methods as well as static and dynamic sink-or-swim separation, setting sorting, spiral separators, There is a sort of hearth sorting.

The operation for the roller mill 12 and the in-bed actuation will be described in more detail below with reference to Fig.

Figure 2 shows a schematic cross-section of a LOESCHE type vertical roller mill 30. The basic constituent of the roller mill 30 is a cone-shaped grinding roller 31 that has been cut at the top of the grinding bed 41. In a partial cross section, only two grinding rollers 31 are shown. However, the vertical roller mill 30 may have three, four, six, or more grinding rollers.

The grinding bed 41 is formed on the grinding fan 32. The grinding roller 31, which is also referred to as a roller, is installed at a fixed position, but it can rotate about an axis as shown in the figure. That is, the grinding fan 32 is rotatable about its central axis as described. If the grinding pan 32 rotates, the grinding material 42 located on the grinding bed also rotates together. The grinding roller 31 rotates through friction between the grinding material 42 and the outer surface of the grinding roller 31.

The sorter 34 is installed above the grinding fan 32 and can be designed static and dynamically. The in-bed deposition process according to the present invention is described in more detail below.

The feed or grinding material 42, such as a concrete slag, is fed to the preparation process via the material feeder 35. The material supply portion 35 is formed such that the supply material 42 is supplied to the center portion of the grinding fan 32.

Through the rotation of the grinding fan 32, the grinding material is accelerated and simultaneously moved outwardly in a spiral shape, causing the grinding roller 31 to rotate thereon. However, in the in-bed induction method according to the present invention, the grinding roller 31 operates in a manner different from a generally known roller mill 30. Where they are basically not used for pressure milling of the grinding material.

In the in-bed induction method according to the present invention, only extremely low contact pressure acts on the grind bed 41 by the grinding roller 31. [ The contact pressure is in the range of 15 kN / m 2 up to 140 kN / m 2. In particular, it is preferred that the range is between 30 kN / m 2 and 80 kN / m 2. The contact pressure basically produces a sufficiently strong shearing force on the grinding bed 41, and the particles in the grinding bed 41 are worn together.

The grinding roller usually has a diameter of up to 2.8 m and a weight of 45 t. This massive weight results in a contact pressure that is much higher than the maximum possible contact pressure in the in-bed actuation. For this reason, there is provided an inverse hydraulic system (not shown in FIG. 2) against the weight of the roller 31. The hydraulic system exerts an opposing force on the rocker arm (33) of the grinding roller (31). In other words, the reverse hydraulic system pushes the rocker arm 33 so that the roller 31 is slightly lifted so that a force against the weight of the roller acts on the roller.

Subsequently, the partially already prepared material located on the grinding pan 32 is displayed through the additional supply of new grinding material 42 and rotation of the grinding pan 32, which may also be referred to as grinding plate, and the retention rim 36 ) Into the gap between the grinding fan 32 and the mill housing.

Through the operation of both the over-running and air stream modes, the first separation takes place at this point. A portion of the over-run treated material may be removed from the process circuitry as the over-run treated coarse material is moved by the process air 37 that is blowing in the direction of the sorter 34 from below.

The basic characteristic of the first separation is the supply amount of the supply air 37. In addition, the separation can also be effected by the blade ring 38. Where the process air 37 is adjusted with the blade ring 38 so that the grit and sand are basically removed from the process circuit as the overlaid coarse material 51. This is then screened as shown in FIG.

The adhesive material of the grit and / or sand, which is not yet sufficiently worn and has cement stones, can also be removed from the process circuit as over-running coarse material 51. As already shown in Fig. 1, the adhesive material is then re-supplied to the process circuit with a new concrete crusher.

The first sorting, referred to as density classification, is carried out through the process air and the optionally provided blade ring.

The blowing process air 37 moves the crushed cement stone and also the particles of the sand with the cement stone to the sorter 34. A second separation takes place here. This is also a density classification.

Here, using the sorter 34, in particular, the sufficiently ground cement stone is discharged from the process circuit. The ground cement stone is removed from the process circuit with the process air being emitted from the process air outlet.

Adhesive material comprising poorly ground cement stone or cement stone and sand is re-fed to the grinding pan 32 through a grit corn 40 and additional in- do.

Additionally, a roller speed sensor 46 sensing the speed of the roller 31 during the process is provided on the roller 31. The speed sensor is necessary because the roller 31 receives low pressure on the grinding bed in the in-bed actuation and the roller rotates too slowly. If this is sensed by the roller speed sensor 46, the pressure can be temporarily increased to increase the rotational speed of the roller.

A fundamental feature of the method according to the present invention and successful in-bed assertion is that the grinding bed is designed to be high enough so that there are sufficient particles of the feed material for mutual wear or abrasion. The values that can affect the grinding bed will be described in Fig.

Fig. 3 shows a portion of the roller mill 30 of Fig. The same reference numerals as in Fig. 2 are also used here.

In order to effect the grinding bed height s, default feed flow rate m _{m, in,} the height of the grinding roller 31 pressure Fw, the grinding pan speed n _s, wherein the retention rim 36 of the and the circulation flow Is available. The internal circulation flow is not shown in FIG. This is basically the material rejected by the sorter as part of the feed flow m _{m, in} .

The effect of the individual setting parameters will be described in more detail below assuming that the other parameters are constants. The purpose here is to change the grinding bed height s below the roller 31 (i.e. between the roller 31 and the grinding pan 32).

In a simple manner, the grinding bed height s may vary depending on the change in the pressure Fw of the roller 31 that affects the contact pressure. The contact pressure is the force acting on the grinding bed directly below the roller. If the pressure Fw of the roller increases, the grinding material will be further compressed or crushed and the grinding bed height s will decrease. Conversely, if the roller 31 receives a low pressure Fw on the grinding bed 41, the grind bed height s increases.

An increase _in feed flow m _{m, in} increases the grind bed height s. If more material per hour is provided to the grind pan 32, more grinding material will be placed on the grind pan 32, assuming that the material remains in the grind pan for the same amount of time. Inevitably, the flow amount m _m on of the mill is also increased. As a result, the grinding bed height s also increases because more material is present on the grinding pan 32.

The influence of the feed flow m _{m, in} can be generated _in two ways. One is to provide the roller mill 30 with more feed per hour. The other is that the classifier is set differently so that the rejection rate in the classifier is higher and more material is fed back to the grind pan 32. [ If less of the grinding material is removed from the process circuit as a coarse material and instead is transferred to the sorbent as a potential powder, the rejection rate can also be increased by an increase in the process air stream. The supply flow rate m _{m, in} and the internal circulation flow rate inevitably affect the discharge flow rate m _{m, on} . If the internal circulation flow increases, the circulation load increases. In other words, more material is present in the preparation circuit inside the mill. This means that the emission m _{m, on} decreases over time if the expression is different. If the feed flow m _{m, in} increases and therefore more feed material is supplied to the mill, the emission m _{m, on} will inevitably increase.

Another possibility to change the grinding bed height is to increase the speed n _s of the fan. If this increases, the grind bed height s will decrease. The higher the grind fan speed n _s , the less the residence time of the material to be processed in the grinding fan 32 is. Therefore, the emission amount m _{m, on of} the grinding fan will also be reduced. Therefore, the height s of the grinding bed inevitably decreases.

An additional possibility of affecting the grinding bed height s is the retention rim 36. If the height h increases, more material will accumulate on the grinding plate. Which in principle means that more material is present at the top of the grinding pan 32 in order to be discharged from the grinding pan 32 together with the emission m _{m, on} .

The basic nature of all the variables mentioned here is that they can interact. The high retention rim 36 results in a higher grinding bed while a longer residence time of the feed material in the grinding pan 32. This allows wear to occur well between them depending on the pressure Fw of the roller 31, but may lead to undesirably long compression times under certain conditions or to low throughput under certain conditions.

By way of example, the individual features of the method according to the invention and the vertical roller mill according to the invention have been described together. It is evident, however, that each characteristic can be used individually.

Similarly, the examples of Figures 1 and 2 relate to the preparation of concrete crushing. However, the method according to the invention can be used for preparation and separation of various other mixed multi-component systems. For example, the in-bed attraction inside the roller mill using only the frictional force of the material to be treated and not actually crushing can be achieved by the use of a natural slate of clay shale and impurities such as lime, ore or other organic constituents It can also be used for preparation. This ensures that the slate is ground by the friction force of the natural slate, but that the individual particles of the ground slate remain in a plate-like shape.

Similarly, the process is also suitable for the process of mica, which consists of a sheet silicate and possible impurities. So far, mainly pure deposits have been utilized. However, this is because the proper preparation of dry and se-paration has not been known until now.

The process according to the invention can also be used to prepare kaolin comprising industrial sand consisting of kaolin, feldspar and quartz sand. The use and preparation of graphite ore, consisting of graphite, ore matrices and mud or bentonite and contaminated by sand or non-sheet-silicates, as well as separation of the adhered constituents It is possible according to the present invention to crush through a heavy mineral sand and to separate rutile, zircon, and titanium slab from the crushing of the sand. Even FeCr slag composed of slaking slag, corresponding metal and stable slag under certain conditions can be prepared. However, an important feature here is that the metal component should be a non-ductile component. Otherwise, wear is not possible according to the method of the present invention and frictional force according to the present invention can not be generated.

With the method according to the present invention and the roller mill according to the present invention, it is possible to prepare and separate the mixed multi-component system simply and efficiently.

Claims (15)

A method for preparing and separating a material comprising a mixed multi-component system,
Wherein the mixed multi-component system includes at least a first component and a second component connected to the first component, wherein none of the two components is malleable,
The material is fed to a roller mill 30 having a grinding fan 32 and a grinding roller 31 for in-bed attrition as the feed material 42,
A grinding bed 41 comprising a material to be treated and a treated material is formed on the grinding pan 32 during processing,
The grinding roller 31 rotates on the grinding bed 41 during the process,
The material is separated into the first and second components through shear forces and friction between the constituent particles by the grinding roller (31) at the grinding bed (41) during the in-bed induction,
The particles of the first constituent, the particles of the second constituent and the particles of the same constituent are worn together,
For the in-bed actuation, the roller mill 30 is designed so that a contact pressure in the range of 15 kN / m 2 to 140 kN / m 2 is applied to the vertically protruding portion of the average roller diameter, And no pressure-based crushing of the second component is operated with only the pressure Fw of the roller 31 selected so as not to occur through the contact pressure,
The roller mill 30 is operated in such a manner that the grinding bed 41 has a minimum height greater than the diameter of one of the two components,
Wherein at least the first and second components are removed and sorted from the process circuit of the roller mill (30). The method according to claim 1,
Wherein the pressure is selected such that the shear force between particles generated during the in-bed actuation ranges from 5 kN / m2 to 70 kN / m2. The method according to claim 1,
Wherein the grinding bed height (s) is adjusted to be at most 8% of the grinding fan diameter. The method according to claim 1,
Wherein the grinding bed height (s) is adjusted to be 4% of the grinding fan diameter. The method according to claim 1,
The grinding bed height s at the required pressure Fw is determined by the feed flow amount m _{m in} , the grinding fan speed n _s , the height h of the retention rim of the grinding fan 31, Lt; RTI ID = 0.0 > flow. ≪ / RTI > 6. The method of claim 5,
The method of claim 1, wherein as the material combination of the multi-component system increases, the pressure (Fw) increases to maintain the grinding bed height (s) to achieve the _in- ) Increases, the height (h) of the retention rim increases and the internal circulation flow increases or the grinding fan speed (n _s ) decreases. 6. The method of claim 5,
Characterized in that to increase and to increase the supply flow rate (m _{m, in)} the amount of processing increases in order to maintain the grinding fan speed (n _S) is the grinding bed height (s). The method according to claim 1,
Characterized in that the roller mill (30) is initially actuated with a pressure (Fw) of the grinding roller (31) higher than the pressure (Fw) selected during operation. The method according to claim 1,
The rotation of the grinding roller 31 is monitored during operation and if the rotation of the grinding roller 31 is surely too slow, the pressure Fw of the grinding roller 31 increases over time How to. The method according to claim 1,
Characterized in that the roller mill (30) is operated in an over-running or air stream mode. The method according to claim 1,
A concrete crusher containing grit, sand and cement stone is supplied as a material and through the in-bed attraction the grit and sand are separated from each other and from the cement stone Lt; / RTI > 11. The method of claim 10,
A vertical roller mill with a sorter 34 is used,
Wherein the process air stream is adjusted in such a way that at least some of the mixture of cement stone and cement stone and sand from the over-running grinding material is transferred to the sorter (34) by the process air stream, the grit The sand is a coarse material and the grinding roller 31 is removed in the process of rotating on the grinding bed 41 and the crushed cement stone is removed from the sorter 34 as a powder and not only the cement stone The mixture of cement stone and sand is sorted by the sorter 34 and fed back to the grinding pan 32,
Characterized in that the sand is separated from the coarse material emitted by the screen. A rotatable grinding pan 32 on which a grinding bed 41 of a grinding material 42 comprising a first component and a second component is formed,
At least two stationary rotatable grinding rollers 31 rotating in the grinding bed 41 during the process,
A classifier 34 disposed above the grinding roller 31, and
And means for forming and maintaining a minimum grinding gap between the grinding fan (32) and the grinding roller (31)
There is provided a hydraulic system for adjusting the pressure Fw of the grinding roller 31 during operation, the hydraulic system having a contact pressure in the range of 15 kN / m < 2 > to 140 kN / m & A portion corresponding to the weight of said grinding roller,
In operation, the hydraulic system is adapted to adjust the contact pressure to perform in-bed attrition and to perform pressure-based grinding of the first component and the second component directly through the contact pressure, Is not performed. ≪ / RTI > 14. The method of claim 13,
A monitoring system (46) is provided on each grinding roller (31) for monitoring the rotation of said grinding roller (31) during processing.




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