DE19629473A1 - Separation of recovered plastics mixture into light and heavy material - Google Patents

Abstract

Process plant for processing plastic mixtures comprises a processing stage (29) for sorting the materials according to density and/or weight. An agglomerator is connected to the lighter material outlet and a dry processing system is connected to the heavier material outlet. Also claimed is a method for processing plastic material mixtures recovered particularly from vehicle recycling and containing both rigid heavier plastics and lighter, especially foamed plastics.

Description

The invention relates to a method for processing a Plastic mixtures with a high proportion of heavy Plastics according to the preamble of claim 1 and one Installation for carrying out this procedure according to the Oberbe handle of claim 22.

Such a plastic mixture falls in the motor vehicle recycling on. Motor vehicles are shredded and the shredded material then into different fractions separated. One of these fractions, also called a shredder  light fraction is mainly composed of the Plastic components of the motor vehicles. It contains large amounts of hard plastics and other heavy (especially thick-walled) plastic parts, for example wise of the bumpers and the instrument carriers of the Motor vehicles originate, but also light plastics, especially foamed plastics. Beyond that in the shredder light fraction also contain metals that when processing the shredder light fraction from the Plastics must be separated.

It is already a process for processing the shredders light fraction known from motor vehicle recycling (Raw material Rundschau 6/1995, page 191). With this procedure the shredder light fraction is initially with a Bar mill pre-crushed, then agglomerated, sieved and then freed from metallic substances. The on The most agile step in this process is the agglome because it heats up the material to be processed to about 150 ° C and a subsequent cooling and Drying required. At the same time, the agglomeration is a very important process step if a uniform, homogeneous plastic material is to be generated that is too wide ren raw material recovery is suitable.

The invention has for its object a method for Preparation of a plastic mixture mentioned at the beginning ten way to create an inexpensive preparation tion of the plastics is possible, the processed Good enough quality for another material Recovery.  

This object is achieved by creating a method with the features of claim 1 solved.

The method according to the invention is based on the knowledge that that when processing plastic mixtures with a high proportion of hard plastics and other heavy Plastics, such as those used in automotive recycling cling, only part of the material to be processed must be subjected to agglomeration. It has shown that the heavy plastics, which are an essential form part of the mixture to be processed, without agglomeration and without wet process steps like this can be prepared that a recycling of the prepared good, e.g. B. as a reducing agent in steel industry, is easily possible.

For these reasons, the invention provides that material to be processed according to density and / or weight is sorted and that then the light fraction of the material to be processed including an agglomera tion is processed, whereas the heavy fraction (the contains hard plastics in particular) without agglomerates tion is processed dry.

The separation of the material to be processed into an easy fraction and a heavy fraction can basically follow Weight or density. It is also a Kombina tion of these sorting steps conceivable, so that for example only fabrics that have a certain weight and a certain Density exceed who is assigned to the heavy fraction the. It should also be borne in mind that in practice sorting according to density and weight is often not exact  let separate. When using an air classifier for Sorting the material to be processed plays next to the Always the density (and thus the weight) of the Particles play an important role.

The concrete values for the density or the weight, the to distinguish between light fraction and heavy fraction on are provided, u. a. after the planned later use of the processed material. At pneumatic process for the separation of light fraction and Heavy fraction can be, for example, by Set the variation of the air flow in a targeted manner.

When processing the shredder light fraction from the Motor vehicle recycling, the separation criteria are preferred se chosen so that foams of the light fraction and the Classic hard plastics added to the heavy fraction will. In the transition area z. B. plastics with the Density of polystyrene. (With these plastics then it depends essentially on the grain shape and size, which faction they are added to.)

The method according to the invention has over the known Preparation methods have the main advantage that the complex and costly agglomeration only with one Part of the material to be processed is used. About that In addition, the metal is deposited in this process le greatly relieved; because those in the to be processed Metals contained in the material are sorted when the mate rials by density or weight predominantly the heavy fracture  slammed on. You will therefore not be in the agglomerator and it is avoided that they agglomerate Connect the melted plastics.

In a preferred embodiment of the invention Procedures are processed before the separation of the Materials in light fraction and heavy fraction initially magnetic components sorted out. For example wise done in that ferromagnetic components be deposited using an overband magnet.

This embodiment of the invention can thereby weiterge forms that the sorted magnetic inventory parts are crushed that the crushed good again separated into magnetic and non-magnetic components will and that the non-magnetic components again material to be processed. This process can, if necessary, be repeated several times by the magnetic discharge is crushed again in order to non-magnetic components still attached to magnetic Stick to parts, separate.

After removing the magnetic components preferably a shredding of the material to be processed than to a certain, predeterminable size. One can Shredding stage combined in this way with a sieving stage be those particles that have a certain size exceed and form the sieve overflow before the further Processing must first be crushed.  

The crushing is preferably by impact and / or Impact, for example with a hammer mill. This type of shredding works very reliably even then casual if even bigger in the material to be processed Amounts of inert substances, such as. B. broken glass and sand, are included.

The separation of the inert substances can be done on a Fine screen section take place. The inert substances that lead to a largely formed by fines, are considered Bottom of the screen taken from the processing cycle.

After the material is freed from magnetic substances, has been crushed and sieved, this is in good condition for separation into a plastic light fraction and a heavy plastic fraction.

As an easy way to separate into light fractions On and heavy fraction offers a wind sifting. There air is used as a separating medium in wind sifting, this enables density separation without wet preparation levels. This advantage is also achieved when light Fraction and heavy fraction by suctioning off the light fraction be separated.

Basically, the separation can also be done with a wet one Method of sorting by density and / or weight be performed, e.g. B. by using a swim-sink Scheiders or a hydrocyclone.  

After separating the material to be processed in Leichtfrak tion and heavy fraction becomes the light fraction agglome and then preferably sieved and chopped nert.

Since the light fraction, in addition to the light plastic parts, those in motor vehicle recycling, in particular through foam substances are formed, including volatile substances such as B. Paper that may contain is in a variant of the process rens provided that volatile constituents from the agglome light fraction. This can either happen during agglomeration when the agglomerator is provided with appropriate suction devices, or there can be separate suction devices above the flow the agglomerated light fraction.

To ash and other inert substances that agglomerate after remaining in the light fraction to be removed the agglomerated material runs over a fine screen section tet, with the fine material being removed as a sieve underflow.

In order to convert the light fraction into a To transfer homogeneous material, it is advantageous if the agglomerated light fraction again according to density and / or Weight is sorted and those components that a certain weight or a certain density below to re-agglomerate into the agglomerator be tested. This sorting process can also be advantageous an air classifier.  

For processing the light fraction after agglomeration can also be provided that magnetic substances, and especially paramagnetic substances (non-ferrous metals), are sorted out and that particles that have a certain predeterminable size, sieved and crushed will.

In contrast to the light fraction, the heavy fraction of the material to be processed without agglomeration or Regranulate processed.

In a preferred embodiment of the processing ver driving for the heavy fraction is provided that magneti substances, especially (paramagnetic) non-ferrous metal le, and electrostatically chargeable particles sorted out be and that the heavy fraction then on a predeterminable size is crushed and homogenized.

A preferred combination of those described above Process steps for an overall process for processing is the characteristics of the Claim 21 characterized.

In addition to creating a process for processing Plastic mixtures with a high proportion of hard, heavy plastics is used in the present Invention also proposed a system with which this method can advantageously be carried out.

Such a system is characterized by the characteristics of the An characterized 22.  

This system is characterized by a preparation stage to sort the material to be reprocessed by Density and / or weight is provided. The light fraction The result of this treatment stage is an agglomerator downstream, whereas the heavy fraction discharge with a processing device for dry processing without agglomeration or regranulation.

It has been shown that the additional effort involved with the separation of the material flows to be processed into one Light fraction and a heavy fraction and with the separate preparation of these two fractions for plastic mixtures with a large proportion of hard plastics, such as z. B. in motor vehicle recycling due to the considerable savings in the agglome and the simpler separation of the metals is done. With this new processing plant for the Shredder light fraction from motor vehicle recycling a significant cost reduction compared to the known systems tion achieved, while at the same time the end product has sufficient quality, for example as a Reduk to be used in the steel industry.

Preferred embodiments of this system are in the Claims 23 to 37 are claimed. With regard to the Advantages of these variants of the system according to the invention to the above statements on the invention Referenced procedure.

Further advantages of the invention will be apparent from the following Description of an embodiment with reference to the figures become clear.  

Show it:

Fig. 1a to 1c is a diagrammatic representation of various parts of a processing plant for the shredder light fraction from motor vehicle recycling;

Fig. 2 is a suction device for the separation of the light fraction and heavy fraction;

Fig. 3 is an air classifier for the separation of the light fraction and heavy fraction;

Fig. 4 shows a second embodiment of an air classifier for separating light fraction and heavy fraction.

In Fig. 1a are those illustrated processing stages of the plant, in which the material to be treated up to the separation into a light fraction and a heavy fraction.

As a first treatment stage, a magnetic separator 11 is provided, which can be configured, for example, as an overband magnet and to which the shredder light fraction from a motor vehicle recycling system 1 is supplied via suitable conveying means 5 .

The magnetic discharge of the magnetic separator 11 is connected to a hammer mill 12 which is followed by a further magnetic separator 15 . The magnetic discharge of the second magnetic separator 15 leads to a container 16 , while its non-magnetic discharge leads to the non-magnetic discharge of the first magnetic separator 11 .

As the next processing stage, a coarse or medium-sized screen section 21 is provided, the screen overflow discharge of which is connected to a hammer mill 22 , the discharge of which leads back to the screen section 21 .

The sieve underflow discharge of the coarse or medium-grain sieve section 21 is connected to a fine sieve section 25 , the bunterlaufaustrag a container 26 and the sieve overflow discharge is followed by a device 29 for sorting the material to be processed into light fraction and heavy fraction (see FIGS . 2 to 4).

Behind the heavy material of this apparatus 29, the preparation device shown in Fig. 1b is arranged for the heavy fraction of the material to.

This treatment device comprises, as the first preparation stage, a separator 31 for non-ferrous metals (para magnetic metals), which can be designed, for example, as an eddy current separator.

Downstream of the metal separator 31 is an electrostatic separator 32 . Both its discharge for electrostatically chargeable materials and the metal discharge of the metal separator 31 are connected to a container 33 .

The separators 31 , 32 are followed by a cutting mill 35 with a perforated sieve for comminution, a mixing valve 36 for homogenizing the processed material and a bagging station 39 .

In Fig. 1c that part of the processing plant is shown in which the incurred in the device 29, the light fraction is treated.

The first processing stage of this plant section is an agglomerator 41 , which is followed by a fine screen section 42 . The screen underflow discharge of the fine screen section 42 is connected to a container 43 , while its screen overflow discharge leads to an air classifier 44 .

A conveyor leads from the light material discharge of the air classifier 44 back to the agglomerator 41 . The heavy discharge of the air classifier is followed by a non-ferrous metal separator 45 , which can be, for example, an eddy current separator. A container 46 is provided to hold the deposited metals.

The metal separator 46 is followed by a sieving section 47 as the last preparation stage, the sieve overflow discharge of which is connected to a secondary shredding stage 48 .

A downstream of the screen underflow discharge of the screen section 47 is a silo 49 in which the processed material is kept ready for further use.

With the processing system described with reference to FIGS . 1a to 1c, the method according to the invention can be carried out as follows:
The processing plant is fed the shredder light fraction from a motor vehicle recycling system 1 via suitable conveying means 5 . This shredder light fraction consists largely of hard, heavy plastics, which, for. B. from the instrument carriers and the bumpers of the motor vehicles. In addition, the material to be prepared also contains a proportion of light goods, which is mainly composed of foams.

The material to be processed is also ver with metals quantity, because when shredding the motor vehicles a Vermi Machining and hooking of the materials takes place and therefore a clean separation of the shredded material into one Group consisting exclusively of plastics and one made of metals and other heavy materials de fraction is not possible.

The material to be processed is first separated using a magnetic separator 11 into ferromagnetic and non-ferromagnetic components. The ferromagnetic components Be smashed in a hammer mill 12 . Here, plastics, dirt and other materials are chipped off by the ferromagnetic substances. The particular advantage of using a hammer mill is that it also achieves a good comminution result if the material to be processed has large amounts of inert materials, such as, for. B. glass and dirt.

The material crushed in the hammer mill 12 is then separated again into a ferromagnetic and a non-ferromagnetic component with the aid of a further magnetic separator 15 . The ferromagnetic portion is stored in a container 16 for further use; the non-magnetic portion is merged with the non-magnetic portion of the first magnetic separator 11 and passed to a coarse or medium-grain screen section 21 .

The screen overflow discharge of the coarse or medium-grain screen section 21 is formed, for example, by grains with a size of more than 10 mm; however, other separation criteria (e.g. 20 mm) are also conceivable. These grains are crushed in a further hammer mill 22 and then passed again to the screen section 21 . This ensures that only grains with a size of less than 10 mm, which form the sieve underflow of the sieve section 21 , reach the fine sieve section 25 .

Fine material (for example grains with a size of less than 2 mm) is sieved out of the material to be prepared on the fine sieve section 25 and passed into a container 26 as residual waste.

In summary, with the help of the two screen sections 21 , 25, a uniform bulk material is created, which can now be sorted with regard to its density or weight. Furthermore, 25 inert substances were removed from the material to be reprocessed on the fine sieve section, so that the plastic material is only contaminated with very small amounts of foreign substances.

In the device 29 for separating the material to be processed into light fraction and heavy fraction (see FIGS . 2 to 4), the material to be processed is separated into heavy and light substances (heavy fraction and light fraction). A wind sifter is preferably used for this.

Despite the uniform grain size of the in the wind sifter material is not strictly separated according to the density of the particles. The remaining ones also play differences in grain size and grain shape Role. In addition to the density, the weight of the Particles important for sorting.

The separation of the material to be processed into a heavy fraction and a light fraction is for the present Reprocessing procedures are crucial. It has showed that the heavy fraction, which in the first place which comprises hard plastic components of the motor vehicles, can be processed dry without agglomeration, that the processed goods can be recycled.  

As the plastic parts from automobile recycling too a large part made of hard plastics the cost of the method according to the invention Reduce processing considerably. In addition, the Separation of those still contained in the material to be processed Metals significantly simplified as this is the heavy fraction be slammed and therefore there is no risk that they are in an agglomerator with melted art connect fabrics.

The processing of the hard plastics, which are removed as heavy goods from the separating device 29 , is shown in FIG. 1b.

First, with the help of a non-ferrous metal separator 31 , which can be, for example, a vortex current separator, paramagnetic metals are sorted out of the material to be processed and passed into a container 33 .

Then, with the aid of the electrostatic precipitator 32, those materials are removed from the material to be processed which are more electrostatically chargeable than the plastics to be processed. This method is also suitable for the separation of PVC, which has a negative charge compared to almost all other plastics.

The material to be reprocessed, which is freed of metals (e.g. cable residues) and electrostatically chargeable materials, is reduced to a maximum size of 6 mm with a cutting mill 35 and then homogenized in a mixing silo 36 . The homogenized bulk material is filled into bags in a bagging station 39 and kept ready for removal.

The processed heavy fraction is of such high quality on that, for example, in the steel industry as Reduk can be used. This high quality is with a comparatively simple preparation ver drive achieved in which neither agglomeration nor other energy-intensive processing steps, such as B. wet preparation stages, followed by drying of the material require to be applied. Therefore works this process is extremely economical.

The treatment of the light material obtained in the separation into light fraction and heavy fraction is shown in FIG. 1c.

The light fraction, which primarily comprises foams, is agglomerated in the agglomerator 41 . For this purpose, thermal agglomeration is preferably used, in which the material to be processed is melted. Alternatively, compacting (press agglomeration) under pressure is also conceivable.

To volatile components such. B. To remove paper that may be contained in the light fraction, the agglomerator 41 can be provided with suction devices. It is also conceivable that the agglomerator 41 is arranged downstream of a suction bell arranged above the flow of the agglomerated material (see FIG. 2).

The agglomerated material is passed over a fine screen section 42 , z. B. particles with a size of less than 1 mm are taken as the sieve underflow and passed into a waste container 43 . As a result, the ash constituents arising in the agglomeration are removed in particular.

After sieving, the agglomerated material is subjected to a further wind screening. The light material accumulated in the air classifier 44 comprises those parts which were not yet sufficiently compacted in the first agglomeration. These constituents are passed back into the agglomerator 41 and there again subjected to agglomeration.

The heavy material accumulated in the air classifier 44 is distinguished by a uniform particle size distribution and particle shape and is therefore ideally conditioned for further use.

This bulk material is first freed in a non-ferrous metal separator 45 from paramagnetic metals, which are fed into a container 46 , and then comminuted to a grain size of less than 8 mm.

After this final comminution, the processed material is kept in a silo 49 for removal.

Due to the previous agglomeration, the light plastics stored in the silo 49 form a product which can be poured sufficiently and can be used as a reducing agent. It is important that in the present process the agglomeration was limited to those components of the material to be reprocessed for which it was actually necessary to produce a uniform bulk material.

It goes without saying that the above values for the separation criteria with regard to the grain size on the different screen sections 21 , 25 , 41 only give values within a preferred range by way of example. Values between 0.5 mm and 3 min are particularly preferred for fine grain screening. For coarse and medium grain screening, values between 5 mm and 30 mm are particularly conceivable as a separation criterion.

In Figs. 2 to 4 different devices are illustrated which can be used to separate the reprocessed Materi as in light fraction and heavy fraction.

The suction device shown in Fig. 2 comprises an ent long direction A height-adjustable suction bell (Diffu sor 50 ) which device 52 is connected via a connecting part 51 with a Sauglei. The suction line 52 is connected to a Saugge blower 54 and provided with an air quantity regulator 53 , with which the suction power can be varied.

The material to be processed is passed on a vibrating trough 58 under the suction bell 50 . A targeted te variation of the suction power determines which components are extracted from the mixture to be processed. The greater the suction power, the more (and the heavier) components are extracted as a light fraction.

By adjusting the distance between the suction bell 50 and the vibrating trough 58 , this can be adjusted from the size of the parts located on the vibrating trough 58 , which in turn depends on the size to which the material to be processed has previously been crushed.

The extracted light fraction is removed at item 55 and passed on for agglomeration; the heavy fraction remains on the vibrating trough 58 and is processed dry without agglomeration.

In Fig. 3, an air classifier 60 is shown, which is operated in cross current.

The material 66 to be processed sinks to the bottom in the air classifier 60 . Via a wind tunnel 63 , a wind stream 68 is blown transversely to the direction of movement of the material 66 to be processed . The lighter components (light fraction 67 ) are strongly deflected by this wind stream 68 and reach a secondary channel 61 of the air classifier 60 , while heavy components (heavy fraction 69 ) are only slightly deflected and remain in the main channel of the air classifier 60 .

With such a separation of the material to be processed In addition to the density, the shape and size of the Particles play an important role. As a separation criterion are therefore both the density and the weight of the particles of Meaning.

Fig. 4 shows a detailed schematic diagram of a further ren preferred embodiment of the air classifier.

The material to be processed is entered into this air classifier 130 from above by the task 131 and then by the air flow generated by the fan 132 past the magnet 133 (so-called "police magnet" for detecting and removing magnetic components still contained in the material) in the direction of the guide plates 134 , 135 out. The wind deflector 134 and the adjustable deflector 135 serve to guide the air flow and material to be processed into the vibrating channel 136 . Heavy particles sink to the ground at an early stage and reach the output shaft for heavy fraction 138 . The lighter material, however, gets into the vibrating trough 136 .

The vibration channel 136 is set in vibration by the spring drive 140 . In the rear region of the vibrating channel 136 , the granular portion of the lighter material collects on the bottom section 137 and is guided to a scraper chain conveyor 141 , with which it is removed from the air classifier 130 .

The vibrating trough 136 is also connected to the scraper chain conveyor 141 by a wind tunnel 139 . Through this foil parts and other particularly light constituents are blown directly into the middle area of the scraper chain conveyor 141 . This relieves the entrance area of the scraper chain conveyor 141 and prevents clogging by film parts.

Claims (35)

1. Process for the preparation of a plastic mixture with a high proportion of heavy plastics, in particular for the preparation of the shredder light fraction from motor vehicle recycling, characterized in that
that the material to be processed is separated according to density and / or weight into a light fraction and a heavy fraction and that

• a) the light fraction agglomerates and
• b) the heavy fraction is dry prepared without agglomeration.

2. The method according to claim 1, characterized in that magnetic components from the reprocessed Material to be sorted out. 3. The method according to claim 2, characterized in that the magnetic components are crushed that the crushed good again in magnetic and non-magnetic genetic components are separated and that not magnetic components to be reprocessed Material are fed.   4. The method according to any one of the preceding claims, characterized in that the material to be processed al is crushed. 5. The method according to claim 4, characterized in that Particles that have a certain, predeterminable size step, sieved from the material to be processed, shredded to the predefinable size and processed tendency material are fed again. 6. The method according to any one of claims 3 to 5, characterized characterized in that the crushing by impact and / or blow. 7. The method according to claim 6, characterized in that the comminution in a hammer mill ( 12 , 22 ) it follows. 8. The method according to any one of the preceding claims, characterized in that particles that determine a lower, predeterminable size (fine material), from which material to be processed is screened.   9. The method according to any one of the preceding claims, characterized in that the separation of the reprocessing tendency material in light fraction and heavy fraction by means of a wind sifting. 10. The method according to any one of claims 1-8, characterized characterized that the separation of the reprocessed Materials in light fraction and heavy fraction The light fraction is suctioned off. 11. The method according to any one of the preceding claims, characterized in that the agglomerated light fraction is sieved and crushed. 12. The method according to any one of the preceding claims, characterized in that volatile constituents the agglomerated light fraction can be suctioned off. 13. The method according to any one of the preceding claims, characterized in that fines from the agglomerate th light fraction is sieved. 14. The method according to any one of the preceding claims, characterized in that the agglomerated light fraction is sorted by density and / or weight and the light material is passed again into the agglomerator ( 41 ). 15. The method according to claim 14, characterized in that sorting is carried out by a wind sifting. 16. The method according to any one of the preceding claims, characterized in that magnetic substances from the agglomerated light fraction can be sorted out. 17. The method according to any one of the preceding claims, characterized in that particles that determine a te, predeterminable size exceed from the agglomerate sieved th light fraction and on the predeterminable Size to be crushed. 18. The method according to any one of the preceding claims, characterized in that from the heavy fraction of material to be processed be animals. 19. The method according to any one of the preceding claims, characterized in that from the heavy fraction of material to be processed electrostatically chargeable Particles are sorted out.   20. The method according to any one of the preceding claims, characterized in that the heavy fraction of material to be processed to a predefinable size is crushed and homogenized. 21. The method according to any one of the preceding claims, characterized in that

• a) magnetic components with a magnetic separator ( 11 ) are sorted out of the material to be processed;
• b) the magnetic components are crushed, the comminuted material with a further Magnetab separator ( 15 ) is separated into magnetic and non-magnetic components and the non-magnetic components are fed back to the material to be processed;
• c) the material to be processed is reduced to a predeterminable size with a hammer mill ( 22 );
• d) fine material is screened off from the material to be prepared on a fine screen section ( 25 );
• e) the material to be processed is separated by air separation into a light fraction and a heavy fraction;
• f) the heavy fraction is freed from paramagnetic metals by means of a non-ferrous metal separator ( 31 ) and from electrostatically chargeable materials by means of an electrostatic separator ( 32 );
• g) the heavy fraction is comminuted with a cutting mill ( 35 ) and homogenized in a mixing silo ( 36 );
• h) the light fraction is agglomerated in an agglomerator ( 41 ) and then fine material is removed on a fine screen section ( 42 );
• i) the agglomerated light fraction is separated by means of an air classifier ( 44 ) into light goods and heavy goods, the light goods being fed again to the agglomerator ( 41 );
• j) the agglomerated light fraction is freed from paramagnetic metals with a non-ferrous metal separator ( 45 ) and then comminuted to a predeterminable size.

22. Plant for processing a plastic mixture with a high proportion of heavy plastics, in particular for processing the light shredder fraction from motor vehicle recycling, characterized by a processing stage ( 29 ) for sorting the material to be processed according to density and / or weight, the light fraction discharge of which is an agglomerator ( 41 ) is connected downstream and the heavy fraction discharge is followed by a preparation device ( 31-39 ) for dry plastics processing without agglomeration. 23. System according to claim 22, characterized by a magnetic separator ( 11 ), the preparation stage ( 29 ) for sorting according to density and / or weight is upstream. 24. Plant according to claim 23, characterized in that the magnetic discharge of the magnetic separator ( 11 ) is connected to a comminution stage ( 12 ) which is connected upstream of a further magnetic separator ( 15 ), the non-magnetic discharge with further preparation stages ( 21 , 22nd ) the system is connected. 25. Plant according to one of claims 22 to 24, characterized by a shredding stage ( 22 ) which is upstream of the preparation stage ( 29 ) for sorting according to density and / or weight. 26. Plant according to claim 24 or 25, characterized in that the crushing stage ( 12 , 22 ) for crushing is formed by impact and / or impact and in particular as a hammer mill. 27. Plant according to claim 25 or 26, characterized by a coarse or medium grain sieve ( 21 ), the sieve overflow discharge is connected to the size reduction stage ( 22 ). 28. Plant according to one of claims 22 to 27, characterized by a fine-grain sieve ( 25 ) for screening fine from the material to be processed. 29. Plant according to one of claims 22 to 28, characterized in that the processing stage ( 29 ) for separating the light fraction from the heavy fraction of the material to be processed is designed as an air classifier ( 60 , 130 ). 30. Plant according to one of claims 22 to 28, characterized in that the processing stage ( 29 ) for separating the light fraction from the heavy fraction of the material to be processed is designed as a suction device ( 50-54 ). 31. Plant according to one of claims 22 to 30, characterized in that the agglomerator ( 41 ) is followed by a fine-grain sieve ( 42 ). 32. Plant according to one of claims 22 to 31, characterized in that the agglomerator ( 41 ) is followed by a preparation stage ( 44 ) for sorting the agglomerated light fraction by density and / or weight, the light material discharge of which is connected to the agglomerator ( 41 ) is. 33. Plant according to one of claims 22 to 32, characterized in that the agglomerator ( 41 ) is followed by a metal separator ( 45 ) and a comminution stage ( 47 , 48 ). 34. Plant according to one of claims 22 to 33, characterized in that the heavy fraction discharge of the treatment stage ( 29 ) for separating the material to be processed into light fraction and heavy fraction, a metal separator ( 31 ) and an electrostatic separator ( 32 ) are connected downstream. 35. Plant according to one of claims 22 to 34, characterized in that a crushing stage ( 35 ) and a mixing silo ( 36 ) are connected to the heavy fraction discharge of the processing stage ( 29 ) to separate the material to be processed into light fraction and heavy fraction.