JP2006181520A - Recycling method for shredder dust and recycling apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recycling method for a shredder dust capable of effectively recycling the shredder dust, and a recycling apparatus. <P>SOLUTION: The recycling method for the shredder dust is a recycling method for the shredder dust including metal pieces, plastic pieces and combustible pieces generated from a waste automobile, waste household electric appliances or the like and is provided with a metal sorting step for sorting the metal pieces included in the shredder dust; a specific gravity difference sorting step for separating the shredder dust removed with the metal pieces by the metal sorting step into the plastic pieces and combustible pieces by difference of specific gravity; and a waste plastic solid fuel molding step for obtaining a waste plastic solid fuel by preparing the plastic pieces and the combustible pieces separated by the specific gravity sorting step so as to become a ratio corresponding to desired calorific power and pressurization-molding it. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for recycling shredder dust generated from scrapped automobiles and the like.

  Shredder dust refers to a mixture of debris such as plastics and combustible materials (cloth, paper, etc.) left after metal materials are recovered after crushing scrap cars and waste home appliances with an industrial shredder. In particular, automobile shredder residue (ASR) generated from scrapped automobiles is generated at a rate of about 20% of the vehicle weight, and the amount generated is about 1 million tons per year. Such shredder dust has a high possibility of environmental pollution, and it is obliged to landfill in a managed disposal site. However, problems such as a shortage of disposal sites have become serious, and the establishment of recycling technology has become an urgent issue. ing.

Japanese Patent Laid-Open No. 2004-890

  However, shredder dust is very difficult to reuse because various kinds of debris are mixed, and there is no effective recycling technology at present. For example, Patent Document 1 discloses a technique for selecting fine metal pieces contained in shredder dust. However, a large amount of remaining plastics and combustible materials must be disposed of in landfills. The problem of lack of space has not been solved. In particular, since incineration of shredder dust has been prohibited in recent years, bulky plastics and combustible materials that are not incinerated make the problem of insufficient disposal sites even more serious.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a shredder dust recycling method and a recycling apparatus capable of effectively reusing shredder dust.

Means for solving the problems / effects of the invention

In order to solve the above problems, the shredder dust recycling method of the present invention is:
A method for recycling shredder dust, including metal pieces, plastic pieces, and combustible pieces, generated from scrapped automobiles and waste home appliances,
A metal sorting process for sorting metal pieces contained in the shredder dust,
A specific gravity difference step for separating the shredder dust from which the metal pieces have been removed by the metal sorting step into a plastic piece and a combustible piece by a specific gravity difference;
A waste plastic solid fuel molding step in which the plastic piece and the combustible piece separated by the specific gravity difference step are blended so as to have a ratio corresponding to a desired calorific value, and a waste plastic solid fuel is obtained by pressure molding,
A method for recycling shredder dust.

In order to realize such a method, the shredder dust recycling apparatus of the present invention is
A shredder dust recycling device that contains metal pieces, plastic pieces, and combustible pieces generated from scrapped automobiles and home appliances,
Metal sorting means for sorting metal pieces contained in the shredder dust,
Specific gravity difference separating means for separating the shredder dust from which metal pieces have been removed by the metal sorting means into plastic pieces and combustible pieces by specific gravity difference;
A blending means for blending the plastic piece and the combustible piece separated by the specific gravity difference means so as to have a ratio corresponding to a desired calorific value;
Pressure molding means for pressure-molding the mixture obtained by the blending means to obtain a waste plastic solid fuel;
It is characterized by providing.

  According to the present invention, for shredder dust containing metal pieces, plastic pieces, and combustible material pieces, after removing the metal pieces, the remaining plastic pieces and combustible material pieces are separated, and these are blended again at a predetermined ratio. To form waste plastic solid fuel. Through such a series of treatments, the shredder dust can be used for recycling metal pieces, and the remaining plastic pieces and combustible pieces can also be used as waste plastic solid fuel. That is, almost all the components constituting the shredder dust can be effectively reused.

  Next, the method for recycling shredder dust according to the present invention includes blending at least incineration ash and fiber material into an excess plastic piece that does not contribute to the formation of the waste plastic solid fuel among the plastic pieces separated by the specific gravity difference step. Then, it is possible to provide an artificial crushed stone molding step of obtaining artificial crushed stone by extruding and crushing the obtained lump.

  For this purpose, the shredder dust recycling apparatus according to the present invention includes at least incineration ash and fibrous material in excess plastic pieces that do not contribute to the formation of the waste plastic solid fuel among the plastic pieces separated by the specific gravity difference means. And an extrusion molding means for extruding and mixing, and a crushing means for crushing the lump obtained by the extrusion molding means to obtain artificial crushed stone.

  In general, plastic has a strong effect of increasing the amount of heat generated by waste plastic solid fuel, and combustible materials have a function of decreasing the amount of heat generated by waste plastic solid fuel, so that all plastic and combustible fragments contained in shredder dust can be removed. If mixed, the desired calorific value may be exceeded. Therefore, by adding incineration ash and fiber to the surplus plastic pieces as described above to obtain artificial crushed stone, the constituents contained in the shredder dust can be effectively reused without being left over.

  Next, according to the recycling method of the shredder dust of the present invention, in the metal sorting step, the vinyl chloride plastic contained in the plastic piece is separated together with the separation of the metal piece, and at least the incineration ash and the fiber material are separated into the vinyl chloride plastic piece. It is possible to provide an artificial crushed stone molding step for obtaining artificial crushed stone by blending and extruding and crushing the resulting mass.

  For this purpose, in the shredder dust recycling apparatus of the present invention, the metal sorting means is capable of separating the vinyl chloride plastic contained in the plastic piece together with the separation of the metal piece, and at least the vinyl chloride plastic piece is included in the vinyl chloride plastic piece. It can comprise so that the extrusion molding means which mix | blends an incinerated ash and a fiber material and extrusion-molds, and the crushing means which crushes the lump obtained by this extrusion molding means, and obtains artificial crushed stone.

  Since vinyl chloride plastics are harmful when burned, they are separated from other plastics in the metal sorting process (means) to form artificial crushed stone, so that vinyl chloride plastics are not included in waste plastic solid fuel. Can be effectively reused.

<First embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows the overall configuration of a shredder dust recycling method and recycling apparatus according to the first embodiment. A recycling apparatus 1 shown in FIG. 1 recycles shredder dust generated from waste automobiles, waste home electric appliances, etc., and mainly includes metal sorting means 8, specific gravity difference means 3, waste plastic solid fuel (RPF) molding means 4. , Constructed by artificial crushed stone forming means 5. In addition, about the metal selection means 8, only the electrostatic selection process part 2 of the last part is shown in figure, and the description regarding another structure is mentioned later. The shredder dust includes, as a typical example in the case of automobile shredder dust (ASR), about 10% of metal pieces, about 40% of plastic pieces, and about 50% of combustible pieces such as cloth and paper.

  An outline of the shredder dust recycling method using the recycling apparatus 1 will be described with reference to the overall view of FIG. 1 and the flowchart of FIG. Here, only the outline will be described here, and the details of each will be described later. First, the metal piece is separated from the shredder dust in the metal sorting means 8 (metal sorting step: S1). The metal piece separated here is reused. Further, the separation of the metal pieces here also has the significance of preventing inclusion in waste plastic solid fuel (RPF) obtained later. On the other hand, the shredder dust (plastic pieces and combustible pieces) from which the metal pieces have been removed is transported by the conveyor B1 and combustible with the plastic pieces using the specific gravity difference in the specific gravity difference means 3 (specific gravity difference-specific process: S2). Separated into pieces. Thereafter, the separated plastic pieces and combustible material pieces are respectively conveyed by conveyors B2 and B3, and in the waste plastic solid fuel molding means 4 (waste plastic solid fuel molding step: S3a), the blending means 41 generates a desired calorific value (for example, , 6000 to 7000 kcal / kg (coal equivalent), blended so as to have a ratio corresponding to coal, and pressure-molded by the pressure molding means 42 to form a waste plastic solid fuel (RPF: Refuse Papaer & Plastic Fuel) ) Is obtained.

  In addition, if the plastic piece contained in the shredder dust contains a vinyl chloride plastic piece, dioxins are generated and harmful if mixed with the above RPF. Is different from other plastic pieces, and sorting is performed in parallel with the sorting of the metal pieces in the electrostatic sorting unit 2 of the metal sorting means 8 (metal sorting step: S1). The sorted vinyl chloride plastic pieces are transported by the conveyor B4, and incinerated ash and fiber are blended in the artificial crushed stone forming means 5 (artificial crushed stone forming step: S3b) and extruded by the extrusion means. The artificial crushed stone is obtained by crushing the obtained lump by crushing means.

  Moreover, as described above, the plastic piece and the combustible material piece separated by the specific gravity difference means 3 (specific gravity difference process: S2) are prepared by the preparation means 41 of the RPF molding means 4 (RPF molding process: S3a). However, when trying to make the ratio corresponding to a desired calorific value (for example, about 6000 to 7000 kcal / kg: equivalent to coal), the plastic piece may be excessive. In other words, plastics generally have a strong effect of increasing the calorific value of RPF, so if all the plastic pieces and combustible pieces contained in the shredder dust are mixed together, the desired calorific value may be exceeded. It is necessary to reduce the amount of plastic when compounding. Therefore, surplus plastic pieces that do not contribute to the formation of RPF are conveyed by the conveyor B4, and incineration ash and fiber are blended in the artificial crushed stone forming means 5 (artificial crushed stone forming step: S3b), The artificial crushed stone can be obtained by extruding and crushing the mass obtained by crushing means.

  With the above configuration, the recycling apparatus 1 can effectively reuse the shredder dust as waste plastic solid fuel (RPF) and artificial crushed stone. That is, RPF is obtained from the shredder dust from which the metal pieces are removed, and all the components of the shredder dust can be reused by obtaining artificial crushed stone from the surplus plastic pieces. Moreover, about the vinyl chloride plastic piece which is harmful when burned, RPF which does not contain harmful substances can be obtained by separately separating it into artificial crushed stone.

  On the other hand, before reaching the RPF molding means 4, an insufficient amount of plastic pieces or combustible materials are provided so that the plastic pieces and combustible materials contained in the shredder dust have a ratio corresponding to a desired heat generation amount. It is also possible to add a piece separately and to make all the plastic pieces and combustible pieces contained in the shredder dust into RPF.

(1) Metal Sorting Step FIG. 4 shows an explanatory diagram of the metal sorting means 8 (metal sorting step S1). Shredder dust is a residue obtained by removing a relatively large member such as a metal material after crushing a scrap car with a tire, glass, engine, battery, etc. removed with an industrial shredder. Plastic pieces and combustible pieces are mixed. In order to remove metal pieces from the shredder dust, the metal sorting means 8 has the following configuration.

  The metal sorting unit 8 sorts metal pieces by combining one or more of a magnetic sorting unit, a stainless sorting unit, a non-ferrous metal sorting unit, and an electrostatic sorting unit. For example, as shown in FIG. 4, first, a magnetic sorting unit, a stainless sorting unit, and a non-ferrous metal sorting unit are arranged in this order. A known sorter can be used for these. That is, the magnetic sorting processing unit sorts and separates iron using magnetic force. In the stainless steel sorting section and the non-ferrous metal sorting section, stainless steel and non-ferrous metal (mainly aluminum) are sorted and separated by utilizing the action of eddy current generated in the metal piece by rotating the permanent magnet. Note that the stainless steel sorting unit and the non-ferrous metal sorting unit have different magnetic field strengths during sorting.

  Further, a trommel (not shown) that can separate noncombustible materials such as earth and sand is provided upstream of the magnetic sorting processing unit. In addition, combustible materials are often attached to the metal pieces selected by the magnetic sorting processing unit, stainless steel sorting processing unit, and non-ferrous metal sorting processing unit, so a wind power sorter that blows air to remove the combustible materials ( (Not shown) are provided for each. The removed combustible material is returned to the shredder dust. In addition, it is possible to combine not only the above-mentioned form but various sorters.

  Next, the metal sorting means 8 has a peeling processing part for separating the metal piece and the plastic piece which are integrated. Shredder dust contains many monolithic objects in which metal pieces and plastic pieces are integrated, that is, coated copper wire whose surface is covered with plastic. Such coated copper wire is sorted by the above sorting section. Separation is difficult, and copper wire is included in the RPF obtained later. Therefore, a peeling process for separating the coated copper wire into a copper wire and a plastic is performed. For example, a volume reducer can be used for the peeling treatment. When the shredder dust is compressed by the volume reducer, the plastic covering the copper wire is melted and solidified by heat generated by the compression frictional heat. Thereafter, the coated copper wire is separated into copper wire and plastic by crushing with a crusher.

  Thereafter, the shredder dust passes through the magnetic sorting processing unit again and reaches the electrostatic sorting processing unit 2 provided in the final portion of the metal sorting means 8. The electrostatic sorting unit 2 charges fine metal pieces (mainly copper wires) made of non-ferrous metal contained in the shredder dust and sorts them using electrostatic adsorption.

  FIG. 3 is an explanatory diagram of the electrostatic sorting processor 2. The rotary drum 22 serving as an electrostatic chuck means is driven by transmission of the power of a motor (not shown), and continuously conveys shredder dust disposed on the surface. The rotating drum 22 is made of a conductive material, and acts as an electrostatic adsorption means when grounded (grounded). Below the rotary drum 22, a collection unit 23 (hereinafter also referred to as a chute) for separating and collecting the shredder dust is provided along the rotation direction. The brush 27 provided so as to come into contact with the rotary drum 22 above the collection unit 23 is for scraping off the shredder dust (mainly vinyl chloride plastic) adsorbed on the rotary drum to the end.

  Above the rotating drum 22, a supply feeder 26 is provided in a state of being inclined forward via a vibration device (not shown). This vibration device is for transporting the shredder dust on the supply feeder 26 while finely vibrating the shredder dust toward the rotating drum 22. The tip of the supply feeder 26 is located on the rotary drum 22. A supply hopper 28 for supplying shredder dust to the supply feeder 26 is provided above the supply feeder 26. While the shredder dust is being transported to the supply feeder 26 (that is, before the shredder dust is charged), the dryer 25 for drying the shredder dust in advance, and the charge removal for removing the charge of the shredder dust in advance. Means 24 is provided to perform a drying process and a charge removal process. This static elimination means 24 performs AC corona discharge.

  Discharge device 21 as a charging means is provided in front upper part of rotating drum 22. The discharge device 21 is for generating corona discharge between the surface of the rotary drum 22 and the shredder dust is charged by the corona discharge. More specifically, the discharge device 21 includes a plate-like electrode (discharge plate) 21 a provided along the surface of the rotating drum 22 and a high-voltage power supply device 21 b that supplies power to the plate-like electrode (discharge plate) 21 a.

  In the electrostatic sorting process using the electrostatic sorting unit 2 described above, the shredder dust previously crushed is subjected to a drying process and a charge eliminating process, and then the shredder dust is disposed on the rotating drum-shaped grounding body 22. Then, charging is performed by the charging means 21. The charged shredder dust disposed on the surface of the rotating drum-shaped grounding body 22 has the metal pieces charged and removed by the drum-shaped grounding body 22 and the plastic pieces and the combustible material pieces as the drum-shaped grounding body 22. Are electrostatically attracted to each other and are shaken down into the collection unit 23 provided along the rotation direction of the drum-shaped grounding body 22. Detailed description will be given below.

  First, crushed shredder dust is stored in the supply hopper 28. Here, shredded shredder dust includes metal pieces (mainly copper wire), vinyl chloride plastic, plastic pieces other than vinyl chloride, and combustibles (mainly cloth and paper). The plastic pieces other than vinyl chloride include acrylic, nitrile, butadiene, styrene, polystyrene, polyethylene, polypropylene, polyethylene terephthalate, and the like. Such shredder dust is supplied from the supply hopper 28 and conveyed forward by the vibrating supply feeder 26.

  During transport by the supply feeder 26, the shredder dust is dried by the dryer 25. Generally, shredding dust contains moisture because crushing treatment of a scrap car is performed while sprinkling water to prevent ignition. Therefore, the below-mentioned fractionation can be effectively performed by removing moisture in advance. After the drying process, the shredder dust is neutralized by receiving AC corona discharge by the neutralizing means 24. That is, the shredder dust is charged by friction between the fragments in various processing steps before being supplied to the supply hopper 28. In the case of performing separation using electrostatic attraction described later, it is important that all pieces are set to the same condition (zero charge) before the separation process. After performing the static elimination process, the shredder dust is supplied from the tip of the supply feeder 26 onto the drum-shaped grounding body (rotating drum) 22 that rotates in the direction of the arrow in the figure. Corona discharge is generated between the rotary drum 22 and the discharge plate 21a by a high voltage from the high-voltage power supply device 21b, and each piece of shredder dust is charged by passing through this space.

  Of the charged shredder dust, a metal piece such as copper loses its charge instantaneously due to contact with the rotating drum 22 and falls as it rotates without rotating the rotating drum 22, It reaches the first chute 23a provided at the forefront. In this way, metal pieces such as copper are mainly collected in the first chute 23a.

  On the other hand, the plastic piece and the combustible piece are electrostatically attracted to the rotating drum 22 because the charge is not easily lost. That is, since they do not have electrical conductivity, only the portion in contact with the rotating drum 22 loses its charge, and the other portions are not instantly lost and are attracted to the rotating drum 22 by this. It is. Therefore, unlike metal pieces that lose their charge instantly and fall naturally, plastic pieces and combustible pieces lose their charge gradually in a state where they are electrostatically adsorbed to the rotating drum 22 and are rotated to some extent. It falls and reaches the second chute 23b at the back (back in the rotation direction) than the first chute 23a.

  In addition, since vinyl chloride plastic has the greatest charging tendency among general plastics, vinyl chloride plastic continues to be electrostatically adsorbed to the rotating drum 22 unlike other plastic pieces. Finally, the vinyl chloride plastic is scraped off by the brush 27 in contact with the rotating drum 22 and reaches the third chute 23c.

  Thus, the first chute 23a is mainly made of metal pieces, the second chute 23b is mainly made of plastic pieces (other than vinyl chloride type) and combustibles, and the third chute 23c is mainly made of vinyl chloride type plastics. Is recovered. As described above, the metal piece is used as it is, and the plastic piece (other than the vinyl chloride type) and the combustible material are sent to the next specific gravity difference distinction means 3 (specific gravity difference distinction step: S2). Is transported to the artificial crushed stone forming means 5 (the artificial crushed stone forming step: S3b). In the electrostatic sorting process described above, the same process is repeated multiple times, and the process is performed on pieces of uniform size by sieving, etc., in order to further accurately sort. Can do.

(2) Specific gravity difference-specific process The specific gravity difference-specific process S2 by the specific gravity difference-specific means 3 will be described. The specific gravity difference discriminating means 3 (see FIG. 1) can have the same configuration as a general-purpose specific gravity difference sorting device. Specifically, the specific gravity differential means 3 includes an inclined plate 32 and a vibration exciter 31 that vibrates the inclined plate 32, and vibrates the plastic piece and the combustible piece conveyed by the conveyor B1 on the inclined plate 32. Then, using the fact that the point of falling from the diaphragm 32 is different due to the difference in specific gravity between the two, each is collected in the collection unit 33.

  The inclined plate 32 is inclined in one direction with respect to the horizontal and is further inclined in a direction crossing the inclined direction. Further, the inclined plate 32 is provided with a number of mesh-shaped holes, and blows air from the back side by a blower to generate an updraft on the surface. Due to the effects of the vibration of the inclined plate 32 and the rising airflow, the plastic piece and the combustible piece having different specific gravity fall from different points of the vibration plate 32.

  The plastic pieces and the combustible pieces that have fallen from different points in this way are respectively collected in the combustible piece chute 33a and the plastic piece chute 33b provided corresponding to the respective dropping points. And a plastic piece and a combustible material piece are conveyed separately to the following RPF shaping | molding means 4 (RPF shaping | molding process: S3a). In addition, as mentioned above, since the plastic piece obtained here may be many with respect to the combustible material piece obtained in order to make RPF, a part of plastic piece is made into said metal sorting means 8 (metal sorting). Step: Together with the vinyl chloride plastic piece separated in S1), it can be sent to artificial crushed stone molding means 5 (populated crushed stone molding step: S3b). For this purpose, for example, the conveyor B3 carrying the plastic pieces is vibrated by a shaker, etc. so that a predetermined amount or more of the plastic pieces are shaken off, or the weight or the like is sensed and the predetermined amount or more is detected. Supply amount adjusting means for controlling the plastic piece to move to the conveyor B4 can be added. In this case, these serve as a blending means for blending the plastic piece and the combustible piece so as to have a ratio corresponding to a desired calorific value in the RPF molding step S3a described later.

  In addition, since the various plastics contained in the plastic pieces also have different specific gravities, the specific gravity difference discriminating means 3 can be configured to further subdivide the chute of the collection unit 33 and sort the plastics according to the type of plastic. . In this way, if the plastics are classified for each type and supplied for each type in the next RPF molding means 4 (RPF molding step: S3a), the amount of heat generated from the waste plastic solid fuel (RPF) is further adjusted. It becomes easy.

(3) Waste Plastic Solid Fuel (RPF) Molding Process FIG. 5 is an explanatory diagram of the RPF molding process S3a by the RPF molding means 4. In this step, the plastic piece and the combustible piece once separated by the above-described specific gravity difference means 3 (specific gravity difference step: S2) are mixed by the blending means 41 with a desired calorific value (for example, 6000 to 7000 kcal / kg). A ratio corresponding to the degree (equivalent to coal) is prepared and pressure-molded by the pressure-molding means 42 to obtain pellet-shaped waste plastic solid fuel (RPF: Refuse Paper & Plastic Fuel). In the present embodiment, since the metal that is not preferable as a raw material is removed by the above-described metal selection step, a high-quality RPF can be obtained.

  The blending means 41 can be configured as, for example, a variable-feed screw feeder that supplies plastic pieces and combustible pieces stored in the hoppers 43a and 43b to the pressure molding means 42. Specifically, a screw feeder is provided in each of the hoppers 43a and 43b, and a predetermined amount of plastic pieces and combustible pieces are supplied from each of the hoppers 43a and 43b so as to obtain a desired heat generation amount. In addition, the blending means 41 can have not only adjustment of the supply amount but also, for example, a function of mixing or crushing both. As described above, the amount of the plastic piece may be adjusted at the time of separation by the specific gravity difference means 3 (specific gravity difference process: S2).

  The pressure molding means 42 can be configured as a ring die type molding machine. That is, the pressure molding means 42 includes a cylindrical ring die 45 and a roller 44 that rotates inside the cylindrical ring die 45. The mixture of the plastic piece and the combustible material supplied to the inside of the ring die 45 is transferred by the roller 44. By pressing against the inner peripheral surface, the ring die 45 is extruded in a columnar shape from a plurality of through holes 45a. The pressure forming means 42 may rotate the ring die 45 together with the roller 44.

  More specifically, as shown in FIG. 5 (b), the roller 44 is disposed close to an arbitrary position on the inner periphery of the ring die 45. The mixture of the plastic piece and the combustible piece supplied to the inside of the ring die 45 begins to be compressed from the near side by the roller 44 and the ring die 45, and is melted or semi-molten by the frictional heat generated accordingly. It becomes a state. Then, the molten or semi-molten mixture is pushed into the through hole 45a at a position close to the roller 44 and the ring die 45, and pushed out to the outside in a columnar shape. Thereafter, the mixture of the plastic piece and the combustible piece extruded in a columnar shape is cut off by a cutter (not shown) provided along the outer periphery of the ring die 45 to be in a predetermined pellet shape. The pressure molding of RPF is performed as described above. In the present embodiment, a ring die type molding machine is used. However, the present invention is not limited to this, and various types such as a screw extrusion type and a disk die type can be employed.

(4) Artificial crushed stone molding process In FIG. 6, explanatory drawing of artificial crushed stone molding process S3b by the artificial crushed stone forming means 5 is shown. In the process, among the plastic pieces separated by the specific gravity difference distinction means 3 (specific gravity difference distinction process: S2), those not transported to the RPF molding means 4 (RPF molding process: S3a), or the electrostatic separation part described above 2 (electrostatic separation step: S1) The vinyl chloride plastic piece separated by incineration ash and fiber is blended, extruded by the extrusion means 51, and the resulting mass is crushed. The artificial crushed stone is obtained by crushing with 52.

  The extrusion molding means 51 of the artificial crushed stone molding means 5 mixes plastic pieces (including vinyl chloride) supplied from the hopper 55, incineration ash, fiber materials, and the like. The artificial crushed stone forming means 5 has a heating means 53 for heating the mixture before press molding by the extrusion molding means 51, and melts the mixture. Thereafter, the molten mixture is extruded into a columnar shape by the piston 54, and the cooled and solidified mass is crushed using a crushing means 52 such as a crusher for rocks or plastics. The artificial crushed stone obtained in this way has sufficient strength and weight to be used as a crushed stone in a lump of waste plastic, and the surface has a roughness like natural crushed stone. It can be used for asphalt aggregate, concrete aggregate, tile, brick, tile, block and the like.

  Generally, the plastic pieces contained in the shredder dust are a mixture of thermoplastic resin and thermosetting resin. When this is made of artificial crushed stone, the thermoplastic resin is effective as an adhesive that hardens the whole. The resin has the effect of giving the product hardness and brittleness and bringing it closer to the properties of natural crushed stone. In order to obtain such an effect, the plastic piece is preferably configured to occupy about 40 to 60% of the weight of the artificial crushed stone.

  Coal ash can be used for the incineration ash added to the artificial crushed stone. Such incinerated ash has the effect of making the appearance of artificial crushed stone like natural crushed stone. Coal ash is called fly ash and is industrial waste generated in large quantities by burning coal and heavy oil in a coal-fired power plant. Normally, fly ash contains harmful metals such as cadmium and chromium and is difficult to treat, but when added to artificial crushed stone, such harmful metals are surrounded and fixed by the resin, and elution can be prevented. Thereby, the coal ash can be effectively reused together with the effective reuse of the shredder dust. In addition, as the incineration ash, incineration ash of sludge can be used. In order to obtain such an effect, the incineration ash is preferably configured to occupy about 20 to 30% of the weight of the artificial crushed stone.

  The fiber material is dispersed and contained in the artificial crushed stone and has an effect of improving the strength of the artificial crushed stone. For example, a fiber reinforced resin can be used for the fiber. The fiber reinforced resin is also referred to as FRP (Fiber Reinforced Plastics), and is a material in which strength is remarkably improved by reinforcing a plastic using fibers and a resin. Although used as a material for boats and bath tubs, these wastes are difficult to process. However, by adding to the artificial crushed stone in this way, the FRP can be effectively reused together with the effective reuse of the shredder dust. In addition, a fiber, glass fiber, metal fiber, carbon fiber, etc. which comprise cloth (sheet | seat) and a nonwoven fabric can be used for a fiber thing. In order to obtain such an effect, it is preferable that the fiber is configured to occupy about 20 to 30% of the weight of the artificial crushed stone.

  The artificial crushed stone obtained in this way can be formed with a coating material covering its surface. Thereby, the effect of hardening artificial crushed stones and the effect of sealing harmful substances are further enhanced. For example, concrete milk or the like can be used as the coating material. Moreover, various things can be added to artificial crushed stones without being restricted to the above. For example, a MDF waste material can be blended. MDF is made of wood fibers glued with adhesives and molded into a plate shape. It is often used for building materials such as doors and flooring by adhering a resin film printed on the surface of the wood. Separation of the resin film is difficult, and when it is crushed, a fine powder is generated, so that it is difficult to reuse it.

  In addition, the artificial crushed stone may be mixed with a combustible material piece separated from the plastic piece by the specific gravity difference distinction means 3 (specific gravity difference distinction step: S2). When combustible material is blended, it is carbonized by the heating means 53, so that the same effect as the incinerated ash can be obtained.

<Second embodiment>
Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 8 schematically shows the overall configuration of the shredder dust recycling method and recycling apparatus according to the second embodiment. In the following, differences from FIG. 1 will be mainly described, and the same parts will be denoted by the same reference numerals in FIG. 8 to simplify the description. The recycling apparatus 100 shown in FIG. 8 is mainly composed of a metal sorting means 8, a dechlorination means 7, and a waste plastic solid fuel (RPF) molding means 4. As for the metal sorting means 8, only the final electrostatic sorting unit 2 is shown in the same manner as described above.

  A recycling process of the recycling apparatus 100 will be described. First, metal pieces contained in the shredder dust are separated and separated by the metal sorting means 8 (metal sorting step). At this time, in the first embodiment, the selection of the vinyl chloride plastic was also performed, but in the second embodiment, the dechlorination process is performed in a later step, so that the labor for separating the vinyl chloride plastic from the shredder dust is reduced. do not need. Next, the shredder dust (plastic piece and combustible piece) from which the metal piece has been removed is subjected to dechlorination means 7 (dechlorination step) to dechlorinate the vinyl chloride plastic contained in the plastic piece. The dechlorination treatment is performed by heating the shredder dust to about 200 to 300 ° C., for example. If the vinyl chloride plastic is contained in the RPF, problems such as generation of dioxins during combustion and accumulation of chloride in the furnace occur. However, these problems can be solved by performing a dechlorination treatment. The shredder dust that has undergone such dechlorination means is pressure-molded by the pressure-molding means 42 of the RPF molding means 4 (RPF molding step) to obtain RPF. In the RPF molding means 4, the hopper 43 is not divided as in the first embodiment, and there is no blending means.

  The dechlorination means 7 can be constituted by an extruder. That is, when the shredder dust from which the metal pieces are removed is introduced into the extruder main body 71 from the hopper 72 through the feeder, the shredder dust is heated inside the main body to perform a dechlorination process. Chlorine thus separated is led to a chlorination apparatus (not shown) and treated using a reaction with calcium or water. Further, the shredder dust is compressed with heating in the extruder main body 71. Since 90% or more of the shredder dust is made of plastic pieces and combustible pieces and is bulky, for example, it is necessary to enlarge a portion such as a hopper. Therefore, since the volume of the shredder dust can be reduced by performing compression in the extruder main body 71 together with the heating in the dechlorination process, such a problem does not occur. By such heating, the combustible material is carbonized and the volume is reduced.

  Further, the dechlorination means 7 is a calorific value adjusting means for separately adding an insufficient amount of plastic pieces or combustible pieces so that the plastic pieces and combustible pieces contained in the shredder dust have a ratio corresponding to a desired calorific value. 73 is provided. That is, the shredder dust does not always contain plastic pieces and combustible pieces at a rate corresponding to the desired heat generation amount. A quantity adjusting means 73 is provided. The calorific value adjusting means 73 can be constituted by a hopper and a feeder with variable supply amount. Further, the heat generation amount adjusting means 73 can be provided with a plurality of sets of hoppers and feeders. For example, plastic pieces and combustible pieces are stored in each of them, and the supply by the feeder is switched according to the shortage with respect to the above ratio. be able to. In addition, when bulky plastic pieces and other plastic pieces are mixed in the same hopper, the supply by the feeder may not be stable, but by storing these separately in each hopper, stable supply by the feeder is possible It becomes. The shredder dust that has been dechlorinated and compressed in this way is crushed to an appropriate size by the crushing means 74 and conveyed to the hopper 43 of the RPF molding means 4.

<Third embodiment>
Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 7 schematically shows the overall configuration of the shredder dust recycling method and recycling apparatus according to the third embodiment. In the following, differences from FIG. 1 will be mainly described, and the same parts are denoted by the same reference numerals in FIG. 7 to simplify the description. The recycling apparatus 10 shown in FIG. 7 is mainly composed of a metal sorting means 8 and artificial crushed stone forming means 5. As for the metal sorting means 8, only the final electrostatic sorting unit 2 is shown in the same manner as described above.

  A recycling process of the recycling apparatus 10 will be described. First, metal pieces contained in the shredder dust are separated and separated by the metal sorting means 8 (metal sorting step). At this time, in the first embodiment, the selection of the vinyl chloride plastic was also performed, but in the third embodiment, it is necessary to separate the vinyl chloride plastic from the shredder dust in order to obtain artificial crushed stone. And not. Next, the shredder dust (plastic pieces and combustible pieces) from which the metal pieces have been removed is mixed with incinerated ash and fiber in the artificial crushed stone forming means 5 (artificial crushed stone forming step: S3b), The artificial crushed stone is obtained by crushing the lump obtained by extrusion molding and crushing means. Thus, by making all of the shredder dust from which metal reorganization has been removed into artificial crushed stone, even if harmful substances are contained in the shredder dust, these are effectively sealed while being sealed to the artificial crushed stone. It can be reused.

The figure which shows schematically the whole structure of the recycling method and recycling apparatus of shredder dust which concern on one Embodiment of this invention. The flowchart which shows the flow of the recycling method of the shredder dust of this invention Explanatory drawing of the metal separation means which concerns on the shredder dust recycling apparatus of this invention Explanatory drawing of separation of rough metal pieces and stripping process of coated copper wire performed prior to metal separation means Explanatory drawing of the waste plastic solid fuel (RPF) shaping | molding means which concerns on the shredder dust recycling apparatus of this invention Explanatory drawing of the artificial crushed stone molding means which concerns on the shredder dust recycling apparatus of this invention The figure which shows schematically the whole structure of the recycling method and recycling apparatus of shredder dust which concern on 3rd embodiment of this invention. The figure which shows schematically the whole structure of the recycling method and recycling apparatus of shredder dust which concern on 2nd embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recycling device of shredder dust 2 Electrostatic sorting process part 3 Specific gravity difference means 4 Waste plastic solid fuel (RPF) shaping means 5 Population crushed stone shaping means 8 Metal sorting means

Claims (22)

A method for recycling shredder dust, including metal pieces, plastic pieces, and combustible pieces, generated from scrapped automobiles and waste home appliances,
A metal sorting process for sorting metal pieces contained in the shredder dust,
A specific gravity difference step for separating the shredder dust from which the metal pieces have been removed by the metal sorting step into a plastic piece and a combustible piece by a specific gravity difference;
A waste plastic solid fuel molding step in which the plastic piece and the combustible piece separated by the specific gravity difference step are blended so as to have a ratio corresponding to a desired calorific value, and a waste plastic solid fuel is obtained by pressure molding,
A method for recycling shredder dust.   Before reaching the waste plastic solid fuel molding step, an insufficient amount of plastic pieces or combustible pieces are separately added so that the plastic pieces and combustible pieces contained in the shredder dust have a ratio corresponding to a desired calorific value. The method for recycling shredder dust according to claim 1, further comprising a calorific value adjustment step.   Among the plastic pieces separated by the specific gravity difference process, at least the incinerated ash and the fiber are mixed and extruded into the surplus plastic pieces that do not contribute to the formation of the waste plastic solid fuel, and the obtained lump is crushed. The shredder dust recycling method according to claim 1, further comprising an artificial crushed stone forming step for obtaining artificial crushed stone. In the metal sorting step, the vinyl chloride plastic contained in the plastic piece is separated together with the separation of the metal piece,
An artificial crushed stone molding step for obtaining artificial crushed stone by blending at least incinerated ash and fiber into the vinyl chloride plastic piece and crushing the obtained lump is provided. The method for recycling shredder dust according to any one of the above.   Instead of the waste plastic solid fuel molding step, at least incineration ash and fiber are mixed and extruded into the plastic pieces separated by the specific gravity difference step, and the resulting mass is crushed to obtain artificial crushed stone The shredder dust recycling method according to claim 1, further comprising an artificial crushed stone forming step.   The shredder dust recycling method according to any one of claims 3 to 5, wherein in the artificial crushed stone forming step, the mixture before extrusion is heated.   The said metal selection process includes the electrostatic selection process which electrifies the metal piece contained in shredder dust, and sorts using electrostatic adsorption, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. Shredder dust recycling method.   The method for recycling shredder dust according to claim 7, wherein the electrostatic sorting process is performed at the end of the metal sorting step.   9. The shredder dust recycling method according to claim 7, wherein the electrostatic sorting process sorts fine metal pieces made of non-ferrous metal.   10. The metal sorting step of sorting metal pieces by combining one or more of magnetic sorting processing, stainless steel sorting processing, non-ferrous metal sorting processing, and electrostatic sorting processing. The method for recycling shredder dust according to claim 1.   The method for recycling shredder dust according to any one of claims 1 to 10, wherein the metal sorting step includes a peeling process for separating the metal piece and the plastic piece which are integrated. A shredder dust recycling device that contains metal pieces, plastic pieces, and combustible pieces generated from scrapped automobiles and home appliances,
Metal sorting means for sorting metal pieces contained in the shredder dust,
Specific gravity difference separating means for separating the shredder dust from which metal pieces have been removed by the metal sorting means into plastic pieces and combustible pieces by specific gravity difference;
A blending means for blending the plastic piece and the combustible piece separated by the specific gravity difference means so as to have a ratio corresponding to a desired calorific value;
Pressure molding means for pressure-molding the mixture obtained by the blending means to obtain a waste plastic solid fuel;
A shredder dust recycling apparatus comprising:   Before reaching the waste plastic solid fuel molding means, an insufficient amount of plastic pieces or combustible pieces are separately added so that the plastic pieces and combustible pieces contained in the shredder dust have a ratio corresponding to a desired calorific value. The shredder dust recycling apparatus according to claim 12, further comprising a calorific value adjustment unit. Extrusion molding means for mixing and extruding at least incineration ash and fiber material to surplus plastic pieces that do not contribute to the formation of the waste plastic solid fuel among the plastic pieces separated by the specific gravity difference means,
Crushing means for crushing the mass obtained by the extrusion molding means to obtain artificial crushed stone,
The shredder dust recycling apparatus according to claim 12, further comprising: The metal sorting means is capable of sorting the vinyl chloride plastic contained in the plastic piece along with the sorting of the metal piece,
An extrusion molding means for blending and extruding at least incineration ash and fiber with the vinyl chloride plastic piece;
Crushing means for crushing the mass obtained by the extrusion molding means to obtain artificial crushed stone,
The shredder dust recycling apparatus according to any one of claims 12 to 14, further comprising: Instead of the blending means and the pressure molding means,
Extrusion molding means for mixing and extruding at least incineration ash and fiber material to the plastic piece separated by the specific gravity difference means,
Crushing means for crushing the mass obtained by the extrusion molding means to obtain artificial crushed stone,
The shredder dust recycling method according to claim 12, comprising:   The shredder dust recycling apparatus according to any one of claims 14 to 16, further comprising a heating unit that heats the mixture before extrusion molding by the extrusion molding unit.   The said metal selection means has an electrostatic selection process part which electrifies the metal piece contained in shredder dust, and classify | selects using electrostatic adsorption, The any one of Claim 12 thru | or 17 characterized by the above-mentioned. The shredder dust recycling equipment described in 1.   The shredder dust recycling apparatus according to claim 18, wherein the metal sorting unit has the electrostatic sorting unit at a final portion thereof.   The shredder dust recycling apparatus according to claim 18 or 19, wherein the electrostatic sorting unit sorts fine metal pieces made of non-ferrous metal.   13. The metal sorting unit sorts metal pieces by combining one or more of a magnetic sorting unit, a stainless sorting unit, a non-ferrous metal sorting unit, and an electrostatic sorting unit. 21. The shredder dust recycling apparatus according to any one of items 20 to 20. The shredder dust recycling apparatus according to any one of claims 12 to 21, wherein the metal sorting unit includes a peeling processing unit that separates the metal piece and the plastic piece that are integrated with each other. .

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