JPH07290457A - Method and device for processing plastic waste made of different plastics - Google Patents

Abstract

PURPOSE: To optimally treat plastic waste not finely classified comprising various plastics by crushing the plastic waste to remove a metal and flocculating the crushed plastic waste before further crushing the same. CONSTITUTION: Plastic waste is crushed by a pre-crushing device within a receiving device 21 through a feed belt and the pre-crushed plastic waste is re-crushed by a crusher 22 and a metal is separated from crushed pieces by a metal separator 23. Next, crushed plastic pieces are melted by friction force by using the rotor cutter of a flocculating device 27 while passed through a sieve having a pre-selected mesh width to be flocculated. These flocculated plastic particles are re-crushed in a post-cutter mill 29.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for treating plastic wastes, which are composed of different plastics, optionally combined with other substances, for further processing, and also with different substances, optionally combined with other substances. The present invention relates to a device for treating plastic waste made of plastics for further processing.

[0002]

2. Description of the Related Art Waste is today so-called on the one hand so-called valuables collected at home and put in containers, and on the other hand degradable and perishable or strongly contaminated substances are put in another container. Collected.

Valuables may likewise be slightly soiled. These include, for example, a wide variety of plastics such as polyethylene, polypropylene, polystyrene, PVC.
Etc., such as cardboard, paper, and optionally other cellulose.

At the waste collection point, the separation and sorting of radically different substances, namely plastic on the one hand, cardboard and large metals on the other hand, takes place.

The valuables may likewise be slightly soiled. These are also a wide variety of plastics such as polyethylene, polypropylene, polystyrene, PVC.
Etc., such as cardboard, paper, metal, and optionally other cellulose.

At the collection point, the radically different substances are separated or sorted out: plastics on the one hand, cardboard and large metals on the other hand.

Moreover, in part there is a need, especially first, for special reprocessable plastics such as polypropylene or the like, and for quite inexpensive special plastic types such as yogurt cups. When it is possible to intentionally sort, a wide variety of plastic fine sorting devices are provided.

[0008] However, the plastic waste or the plastic fraction contains a large number of, such as yogurt cups or the like, which may be slightly soiled and optionally combined with other materials. Objects that consist of a wide variety of plastics remain. Further separation and sorting are often not possible for technical reasons and some are also undesirable or impractical for economic reasons.

In the past, such non-separable, treatable and unprocessable plastics, often including films, plastic bags, etc., were packaged in bales and stored as such for intermediate storage in a waste dump. Intermediate storage in this bale is associated with significant danger. Because self-ignition can occur quite easily, and at least
Exactly if the plastic bales stored in this way are prone to combustion. In this case, dioxin may be generated during combustion, especially when the plastic waste contains PVC.

Another disadvantage of direct intermediate storage in plastic bales is that the soiled material pressed into the bales is not biologically inert. Bacteria infiltrate the soil components, which in turn expands the veil, increases volume, and causes the package to burst.

The above-mentioned problems are partially due to the fact that there is no continuous or quasi-continuous disposal depending on the degree of the plastic substance concerned, and this disposal is carried out at one collection site for one week or 14 days. It occurs for a few days at most, one day at a time, but for reasons that have to be treated immediately, even for intermediate storage, even in the form of plastic bales or in other forms, for good reasons. .
Moreover, the amount of waste collected at the depot is often so small that in-situ machines such as repelletizers are only used for short periods of time, ie hours. This is because such a machine can be used for a week or 14 until the next collection date of the valuable waste.
This is because not enough waste is provided to be used over the entire working time of the day.

[0012]

Starting from the state of the art and the drawbacks mentioned above, the object of the present invention is
Optimal treatment of unsorted plastic waste consisting of a wide variety of plastics combined with cardboard and metal, and especially eliminating the danger of combustion and biological events of the treated material It was to provide a method and an apparatus capable of doing so.

[0013]

The problem is solved according to the invention in a method of the type described at the outset, which method comprises crushing the waste, separating metals, agglomerating plastic waste, Further, it is characterized in that the aggregated waste is further crushed. In particular, the device according to the invention for carrying out the process comprises a crushing device, a metal separator and at least one agglomerator.

According to an advantageous embodiment of the process according to the invention, the plastic waste is crushed in two steps before agglomeration, the particularly bulky plastic component being fed to the first crushing step by means of a forced feeding device, And the plastic waste components are crushed to a size of about 10 mm before metal separation. According to another advantageous embodiment of the process according to the invention, the first metal separation is already carried out before the first crushing step, said first metal separation being carried out by the metal detector and the manual removal of the metal constituents. In this way, the large metal constituents which remain in the plastic waste during the presort are already removed before grinding.

In a further advantageous embodiment of the first method embodiment according to the invention, the magnetisable metal is used to remove from the plastic waste with a magnet and the nonferrous metal is removed by electrostatic separation. By this means, the metal which is separated from the other plastics only by crushing and precrushing is separated, while the residual metal adhering to the plastic particles, for example the residue of the yogurt cup lid, is fed to another processing of the plastic particles. Yes, and as long as the plastics ingredients are far in excess, they are not an obstacle.

In a very advantageous embodiment, the crushed plastics waste components can be intermediately stored prior to agglomeration to ensure continuous agglomeration.
The agglomeration of the plastic particles is performed by melting them and then passing them through a sieve or a die plate. 3m after quenching with water or after cooling
Particles of m or less can be further crushed. For this and / or for further processing, cooling of the plastic particles heated for agglomeration and crushing is important. In this case, cooling to a maximum of 40 ° C should be performed.

During the agglomeration and the subsequent crushing, on the one hand, in order to avoid deterioration of the plastic properties of the plastic due to too high a temperature, on the other hand, a sufficiently high temperature of more than 80 ° C. can also be introduced into the waste soil constituents. The temperature range should be chosen such that the eradication of the contained microorganisms is achieved and thus a hygienically satisfactory and biologically inert end product is obtained. It has been found that this is immediately achievable with the method according to the invention and the device according to the invention. The product does not show any odor evolution after long-term storage.

According to an advantageous configuration of the second embodiment of the process according to the invention, before feeding the plastic waste for further shredding, the plastic components already having the desired particle size are separated from the other plastic components. To do. According to another configuration, the magnet component is separated from the plastic component to be further crushed. By this means, the metal separated from the other plastics by crushing with pre-crushing is preferably separated from the plastic waste by means of a magnet roller. The residual metal adhering to the plastic particles is fed to the subsequent crushing device, and they are not a hindrance as long as the plastic components make up the majority.

The device according to the invention is preferably a feed ram, in which the receiving device is equipped with a pre-crusher for the bulky components, and in particular the pre-crusher has a cutter mill and is hydraulically moved. It is configured to have a forced supply mechanism having.

Subsequent crushing can be done in a front cutter mill equipped with a shredder or chute.

For metal separation, an overbelt magnet on the one hand and an electrostatic separator for non-ferrous metals on the other hand are provided. Alternatively, the device has for that purpose a metal detector arranged in front of a front cutter mill with magnet rollers on the one hand and chutes on the other hand.

According to a further advantageous embodiment, an intermediate reservoir is arranged in front of the agglomerator to ensure a continuous supply of plastic particles to the agglomerator, and the plastic debris is gravity fed to the agglomerator. An intermediate reservoir is arranged above the agglomerator so that it can be dropped, in particular, the agglomerator has a sheave or die plate and a rotor blade through which the plastic debris is passed after melting. .

According to a first embodiment, a first cooling device is arranged behind the agglomerator, in which the after cutter mill is adjusted so that the final grain size has a diameter of 3 mm or less. Can be connected. According to another embodiment, the flocculator is connected to a device for supplying water. By this means, the plastic component is rapidly cooled. Furthermore, a sieve trough for separating the plastic waste is preferably arranged behind the flocculator in the device for transporting the plastic waste to be processed. By this means, the plastic component already having the predetermined particle size is
It can be discharged in a blower with a cyclone, which has already been separated and followed downstream of the sieve trough. Due to the coarse plastics component, upstream of the sieve trough is followed by a magnet roller for separating the iron-containing metal from the plastic waste.

A method according to the invention and a device according to the invention,
Pelletization of the plastic material takes place by agglomeration and subsequent crushing, in particular behind the work station provided for the preparation work steps or for the preparation of agglomerates.

The pellets obtained can be used in a wide variety of ways and can later be advantageously processed as substitutes for silica sand and anhydrous gypsum when filling cement in underground mining. A significant advantage of the aggregate according to the invention for underground mining lies in the fact that the pellet material obtained does not adsorb water, is light in weight and can be easily transported by fluid transporters and the like.

Apart from the above-mentioned uses, the material can be hydrogenated later. Another field of use is lightweight concrete aggregates, in which case also the abovementioned properties are important, i.e. the light weight as well as the elimination of any water absorption.

According to an advantageous embodiment of the process, sand, corundum, silicon oxide (silica sand) or the like may be added during the agglomeration, especially when used as aggregate for lightweight concrete. it can.

Furthermore, it is possible to carry out a washing of the plastic waste before flocculation for biological inactivation and, optionally, also before crushing. However, the above temperature treatment has been found to be sufficient to achieve a biologically inert material.

The device according to the invention has a capacity of 100 per hour.
It produces 2500 tons a year with a throughput of 0 kg, which corresponds to a consumption of about 300,000 inhabitants a year.

In summary, the present invention is technically acceptable in a very economically favorable manner and processes a wide variety of plastics without the need for high sorting costs, ie in the field of building materials in the downhole or Provided is a method and apparatus for providing a material which, whether aggregate to concrete, is used in a wide variety of applications and which can optionally also be further processed, for example by hydrogenation.

[0031]

The present invention will be described in detail with reference to the embodiments shown in the drawings.

The process according to the invention starts with a waste treatment in which the unfouled or relatively slightly fouled material is collected separately from other, especially perishable, waste. This is shown in FIG. 1 with the frame "yellow bag" with reference numeral 1.
Indicated by. Valuables are fed to a sorting device, where they are sorted by hand or semi-automatically, for example by sorting defined plastics materials, for example entirely specialized plastics components from whole yogurt cups, or paper and board products. Select metal. The original method according to the invention and thus also the device for carrying out said method (this method is shown in the middle part of FIG. 1) are supplied with plastic waste only. However, this waste may be highly mixed on the one hand and contain a wide variety of plastics, such as polyethylene, polypropylene, polystyrene, PVC, and on the other hand metals such as metal lid residues in plastic cups, Alternatively, a composite of paper and cardboard may be present. In the latter case, the plastic component should, of course, make up the majority. Thus, the method according to the invention allows reprocessing to utilize non-perishable plastic waste within the stated range, without the need for high sorting costs. In particular, it can be recovered as pure using the method according to the invention, either for reasons that are technically impossible or too costly or there is no demand for the corresponding plastics. Plastic waste that is not (recyclable) can be treated and reused.

A correspondingly prescreened plastic waste to be processed according to the invention is fed from 3 to the process according to the invention. At that time, the first pre-crushing can already be carried out. The material is then forcibly fed, for example by means of a belt or a packing device, into a shredding device, which may consist of a shredder, which shreds the work piece into shreds having a surface diameter of 10 mm. This crusher also crushes all kinds of metals together (reference number 4). Metal separation is performed in the next process step. This process consists of two types of processes. On the one hand, magnetizable or iron-containing metals are removed by magnets, preferably overbelt magnets arranged on a belt conveyor, while on the other hand they may be relatively small (less than 5 mm) released by electrostatic separators. The non-ferrous metal pieces that have been removed are removed.

In the next main step 7 of the method according to the invention, the crushed plastic material is agglomerated. Since this process should be carried out continuously, the material is intermediately stored at 6 in an intermediate reservoir. The material can be removed from the reservoir for continuous agglomeration, for example exclusively by gravity.
Aggregation can be performed with a rotor cutter that melts based on frictional forces and at the same time passes through a sheave having a preselected mesh width.

Subsequently, at about 100 ° C., which occurs during aggregation at 8 °
The agglomerated plastic particles having a temperature of 4 ° C. are cooled to the temperature of 40 ° C. required for reworking and shipping.
Cooling can be performed by air cooling or a cold water circulation path in the cooler.

Following the above steps, the agglomerated plastic is crushed again at 9 to a specified particle size of 3 mm or less.
This crushing can be performed with a cutter mill.

In this case, too, a temperature rise can occur depending on the working process, so that another cooling step is preferably provided to recool the material to a maximum temperature of 40 ° C. This cooling can be done in the manner described above.

The agglomerates crushed to the desired particle size and cooled are then conveyed, for example using a screw or pneumatic conveyor, to a storage device, for example a silo 11, from which they are further processed. L in an appropriate format
This can be done using KW and / or belt 12.

For the method according to the invention, a fully automatic electric current / heating and refrigerant supply device is provided, which is carried out by the control device 104.

The device according to the invention shown in FIGS. 2 and 3 firstly has a receiving device 21 in which the plastic waste is delivered to a conveyor belt and fed to a first pre-crushing device. It For this purpose, the receiving device 21 has a ram which is hydraulically moved, by means of which the plastic waste is pushed into the cutter in the cutter mill. At this time, the pushing frequency can be set steplessly.

From the receiving device, the optionally pre-crushed plastic reaches a crushing device 22, which is preferably constructed in the form of a shredder, inside which it is crushed to a shred size of 10 × 10 mm. In this case, foreign matter such as metal is also crushed together. In the metal crushing device 22, the metal separator 23
Are connected and the metal separator is configured to perform two functions. On the one hand, it is designed as an overbelt magnet and, on the other hand, as an electrostatic separator for non-ferrous metals.

The core of the processing apparatus according to the present invention is the agglomerator 2
7, the crushed plastic waste is supplied to the agglomerator via the intermediate storage 26, and the plastic waste is blown into the intermediate storage via the pipe system 25a.
Thereby, the agglomerator 27 can be continuously fed with plastic fragments, for example exclusively by its gravity.

The agglomerator 27 comprises a rotor cutter, by means of which the plastic fragments are melted on the one hand by frictional forces and, on the other hand, through a sheave having a preselected mesh width. in this case,
The speed of the rotor cutter is selectable, the speed being adjusted so that melting of the plastic and thus possible agglomeration is achievable. In this case, the temperature rise of the plastic material up to about 100 ° C occurs. This allows
On the one hand, heat sterilization and thus on the eradication of micro-organisms that may still be present in the soiled plastic are achieved, and on the other hand the degradation of the plastic itself, especially polyethylene, is avoided, because it should maintain its plastic properties. Because.

For rework and for further transport,
A cooling device 28 follows the agglomerator, and the plastic particles agglomerated in the cooling device are fed via the pipe system 27a.
After cooling the particles, they are crushed in a post-cutter mill 29, in particular to the desired preselected particle size of 3 mm or less. In addition, additional cooling can take place in the cooler 30 in which the particles are supplied via the tubing 29a. From this chiller, the particles can then be fed to an external storage device, such as a container silo or the like, and from there for further transport.

The entire device, as most apparent from FIG.
It is located on the container bottom 31 and is surrounded by a casing 32, which is shown in phantom in FIG. The container bottom may be configured to be transportable, for example by loading on a semi-trailer 33, which is equipped with wheels 34 and is connectable (at 35) to a towing vehicle.

FIG. 4 shows an advantageous embodiment of the device according to the invention loaded on a semitrailer 33. The material is fed via a connectable conveyor belt 36, which is shown in broken lines, and reaches via a conveyor 37 a shredding device 22, which is preferably configured as a mill.

Optionally, the material may already be pre-crushed and pre-sorted.

From the crushing device 22, the material is initially introduced via a conveyor 25, preferably in the form of a screw, into a reserve damper or intermediate reservoir 26 and from there into a flocculator 28 arranged below it. The agglomerated material is cooled and conveyed further via a conveyor 27a (which is also equipped with a cooling device), in which the metal separator 2 is used to separate residual metal particles.
3a may be provided.

The agglomerated and cooled material then reaches the cutter mill 29 after which it is discharged via another cooling device 30.

The entire device is arranged in a casing 32. A power supply device 42 having a separated soundproof device 41 is also present in this casing.

FIG. 5 shows another advantageous embodiment of the device according to the invention, which device is mounted on a three-axle low loader semitrailer 101. This semi-trailer 101
Has a casing 103 enclosing the device 102, shown exclusively in solid lines in FIG. As is also apparent from FIG. 6, on the back surface 104 of the casing 103, a rod mechanism 105 is arranged somewhat below the casing cover, which rod mechanism can be pushed into the casing during transport of the device and It can be extruded again in the field. The rod mechanism can be covered with waterproof canvas 106 as a rain shield, for example. When operating the device according to the invention,
A supply belt 107 is arranged below the rod mechanism 105 and the waterproof canvas 106, and the material to be crushed is first supplied to the conveyor. With the feed belt 107, the material or feed can optionally be further sorted. Supply belt 1
From 07, the material reaches the conveyor belt 108, which is also configured during operation as a lifting belt which is arranged under the waterproof canvas 106. Like the rod mechanism 105, the supply belt 107 and the lifting belt 108 can be pushed into the inside of the casing 103 during transportation (indicated by a broken line in FIG. 5).

On the rising belt 108, the metal detector 10
9 are arranged. When the metal component is detected, the conveyor belt 108 is stopped and the metal component that remains hidden during the sorting process can be removed by hand. In this way, as much as possible of the mixed plastics reaches via the lifting belt 108 to the pre-crusher 110, which is preferably configured as a mill and has a chute. The pre-crusher or pre-cutter mill 110 equipped with a chute can not only crush mixed plastics, but also crush plastics that have never been sorted, such as plastics with metallic impurities, such as measure containers. .

In the pre-cutter mill 110, the material is pre-crushed to the desired shred size and then reaches the agglomerator 112 directly via a conveyor 111, preferably a discharge or transport screw, without an intermediate reservoir. . This aggregator 112
Work with a rotating cutter bar. The plastic crushed pieces filled in the agglomeration chamber are heated by frictional heat by a rotating cutter bar, agglomerated at about 130 ° C., and quenched with water (therefore the aggregator 112 has a water supply pipe), and then for a short time. It is crushed in the same chamber and then discharged 113 into the sheave trough. The sheave trough 113 is arranged below the agglomerator 112 and is configured in this case to be able to fill all the charges and to feed the sheave via a metering slider.

Since the particles can be already separated by the sheave, the separated particles can be supplied to the cyclone 115 via the blower 114 downstream of the sieve trough 113 and conveyed to the already prepared container via the cyclone. it can. The residual particles of the sheave trough 113 reach the screw 116 via a magnet roller (not shown). The residual metal particles are separated from the plastic via a magnet roller. The material is supplied to the rear cutter mill 117 by the screw 116. In the post-cutter mill, the material is then post-broken to the desired grain size. An external storage device for the material that has been cuttered via the blower 114,
For example, discharge into container silos or the like.

The device further comprises, on the semitrailer 101, in the front region of the casing 103 of the device 102, a generator 118, which is installed in its own casing. Diesel tanks 120 are arranged on each side of the semi-trailer 101 below the generator 118. In the casing 103, the device 102 has a switch box 121 for controlling the device. Further, since the apparatus has one illuminating lamp 122 and 123 respectively outside, the operation of the apparatus is not related to day and night.

Instead of the front cutter mill 110, a flat shredder can be used. In this way, all undisassembled plastic bales can be fed to the chute by a fork stacker and pre-crushed by a shredder. The shredder has a slowly rotating shaft into which the plastic bale is pushed with a hydraulic ram. In this case, the stroke of the ram depends on the current consumption of the shaft drive motor.

Even a device of this compact construction and a relatively small size is sufficient to process up to 2500 tons of plastic waste per year with a time efficiency of 1000 kg / h. This amount of waste is comparable to that of about 300,000 inhabitants per year. However, waste dumps are provided for a significantly smaller number of people, especially in rural areas, up to less than 1/10 of the figure of 300,000. Stationary equipment is uneconomical in such depots, since only such plastic waste is produced in such an amount that it can be treated in hours or days. That's because the equipment can't work five days a week, all the time.

For just such a case, the device according to the invention is optimal. This is because the device is moved to the site of the collection day of the waste collection site concerned, the material is processed after the above-mentioned pre-sorting, and it is moved to the next collection site after a processing time lasting several hours or days. With a predetermined rhythm,
This is because, for example, it can be returned to the starting collection point again at intervals of one week or two weeks.

[Brief description of drawings]

FIG. 1 is a flow chart of an advantageous embodiment of the method according to the invention.

2 is a schematic block diagram of an apparatus according to the invention for carrying out the method of FIG.

FIG. 3 is a schematic perspective view of a transportable, compact device according to the present invention.

FIG. 4 is a schematic configuration diagram of another embodiment of the device according to the present invention.

FIG. 5 is a schematic block diagram of a second embodiment of an apparatus according to the present invention for carrying out a second embodiment of the method according to the present invention.

FIG. 6 is a plan view of the device shown in FIG.

[Explanation of symbols]

21 receiving device, 22, 29, 110, 117 crushing device, 23 metal separator, 26 intermediate reservoir,
27,112 Coagulator, 28,30 Cooling device, 2
9,117 Rear cutter mill, 31 Container bottom,
32, 103 casing, 33, 101 semi-trailer, 109 metal detector, 110 front cutter mill,
113 sheave trough, 114 blower, 115
Cyclone

Claims (25)

[Claims] 1. A method of treating a plastic waste consisting of different plastics, optionally combined with another substance, for further processing, wherein said waste is crushed, metals are separated and plastic waste is removed. A method for treating plastic waste consisting of different plastics, characterized by aggregating and further crushing the agglomerated waste. 2. The method according to claim 1, wherein the plastic waste is crushed in two steps before agglomeration. 3. The method according to claim 1, wherein the bulky plastic component is fed to the first crushing step by a forced feeding device. 4. The method of claim 4, wherein the first metal separation is carried out prior to the first crushing step by manual removal of the metal detector and metal components. 5. The method according to claim 1, wherein the plastic waste component is crushed to a size of about 10 mm before metal separation. 6. The method according to claim 1, wherein the magnetisable metal is removed from the plastic waste with a magnet and the non-ferrous metal is removed by electrostatic separation. 7. The process according to claim 1, wherein the crushed plastics waste components are intermediately stored prior to agglomeration to ensure continuous agglomeration. 8. A process according to claim 1, wherein the plastic component is melted for coagulation and passed through a sieve. 9. The plastic component according to any one of claims 1 to 9, wherein the plastic component is aggregated and optionally quenched with water and then further crushed, in which case the plastic component having a predetermined particle size is separated from the other plastic components. Method described in section. 10. The method according to claim 9, further comprising separating the magnetic component from the plastic component to be crushed. 11. The method according to claim 9, wherein the plastic component is crushed to a particle size of 3 mm or less. 12. A crushing device (2) in a device for processing plastic wastes of different plastics, optionally combined with another substance, for further processing.
2, 29, 110, 117), a metal separator (23) and at least one aggregator (27, 112), for treating plastic wastes of different plastics. 13. Device according to claim 12, characterized in that a receiving device (21) with a pre-crusher for bulky components is provided. 14. Apparatus according to claim 12 or 13, comprising a forced feed device with a feed ram which is hydraulically moved. 15. A front cutter mill (11) provided with a shredder or a chute as a crushing device (22) for crushing plastic waste to a fragment size of 10 × 10 mm.
0) A device according to any one of claims 12 to 14 having 0). 16. A front cutter mill (1) equipped with a chute.
Device according to claim 15, comprising a metal detector (109) arranged in front of 10). 17. A metal separator (23) having an overbelt magnet for removing magnetizable or ferrous metal from waste, as well as an electrostatic separator for non-ferrous metals. The device according to item 1. 18. A flocculator (2) in front of the flocculator (27).
18. Device according to any one of claims 12 to 17, wherein an intermediate reservoir (26) is arranged to ensure a continuous supply of the plastic component to 7). 19. The agglomerator (27, 112) comprises a sheave,
19. An apparatus as claimed in any one of claims 12 to 18 having a rotor blade for passing the plastic debris through the sheave after melting. 20. A flocculator (112) is connected to a device for supplying water to quench the plastic component.
Device according to any one of claims 12 to 19. 21. A sieve trough (113) for separating plastic waste is arranged behind the flocculator (112) in a device for transporting plastic waste to be processed. The apparatus according to claim 1. 22. Device according to claim 21, characterized in that it has a magnet roller arranged aft of the sieve trough (113) upstream for separating the iron-containing metal from the plastic waste. 23. A cyclone (115) for transporting plastic components separated from plastic waste.
23. Apparatus according to claim 21 or 22, having a blower (114) followed downstream of the sheave trough (113). 24. A rear cutter mill (29, 117) is arranged as a crusher behind the aggregator (27, 112) in the conveying direction of the plastic waste to be processed, and the rear cutter mill collects the agglomerate. 24. Apparatus according to any one of claims 12 to 23, configured to crush to a particle size of 3 mm or less. 25. The structure according to claim 1, wherein the structure is transportable.
25. The device according to any one of 2 to 24.