Resin recovery method

Abstract

To provide a resin recovery method capable of improving the recovery rate and recovery concentration of olefin resin.SOLUTION: There is provided a method for recovering resin from a salvage vehicle 11. The method for recovering resin includes the steps of: dismantling the salvage vehicle 11 to obtain a salvage vehicle shell 12; shredding the salvage vehicle shell 12 to obtain a first shredder dust; air-sorting the first shredder dust to obtain first low-specific-gravity dust and first high-specific-gravity dust which is higher specific gravity than the first low-specific-gravity dust; and wet-gravitational-sorting the first high-specific-gravity dust. In the method, interior components 13 containing fiber are removed upon dismantling the salvage vehicle 11. The method for recovering resin further includes the steps of: shredding the interior components 13 to obtain second shredder dust; and air-sorting the second shredder dust to obtain second low-specific-gravity dust and second high-specific-gravity dust which is higher specific gravity than the second low-specific-gravity dust.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for recovering resin from scrapped vehicles. [Background technology]

[0002] In recent years, efforts to significantly reduce waste generation through waste prevention, reduction, recycling and reuse have been gaining momentum. To achieve this, research and development is being carried out into methods for recovering resins from end-of-life vehicles.

[0003] Patent Document 1 describes a method for recycling shredded dust from scrapped automobiles, in which scrapped automobiles are dismantled, crushed, and sorted to remove harmful materials and valuables, and the resulting shredded dust is sorted in a series of processing steps for the shredded dust, and urethane foam or foamed plastic containing urethane as a main component is selectively recovered from the shredded dust. Here, the processing steps include a step of performing a sorting process on the shredded dust that utilizes differences in the repulsive forces of objects, and a step of performing a specific gravity sorting process on a group of materials with relatively small repulsive forces. Here, a wind sorting method is used as the specific gravity sorting method.

[0004] Patent Document 2 describes a method for sorting shredded industrial waste, in which valuable materials are recovered by gravity sorting the shredded industrial waste after removing metals and glass. The method for sorting shredded industrial waste includes a wind sorting step in which the shredded industrial waste is separated into light and heavy materials by wind sorting without being shredded in a stage prior to the gravity sorting step, and a gravity sorting step in which the heavy and light materials separated in the wind sorting step are separately immersed in a sorting liquid for gravity sorting to separate and remove chlorine-containing materials from the light or heavy materials. Here, the shredded industrial waste is shredded material obtained by shredding scrapped vehicles from which reusable parts have been removed using a car shredder, and then removing metals. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-236837 A [Patent Document 2] JP 2008-178846 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the methods described in Patent Documents 1 and 2, the hard plastics containing the olefin resin become entangled with the fibers during wind sorting, and as the amount of recovered low-density dust increases, the recovery rate and recovery concentration of the olefin resin decrease. Here, the low-density dust is mainly used for thermal recovery purposes.

[0007] An object of the present invention is to provide a resin recovery method capable of improving the recovery rate and recovery concentration of an olefin-based resin. [Means for solving the problem]

[0008] (1) A method for recovering resin from a scrapped vehicle, comprising: dismantling the scrapped vehicle to obtain scrapped vehicle shell; crushing the scrapped vehicle shell to obtain a first shredded dust; air-sorting the first shredded dust to obtain a first low-specific-gravity dust and a first high-specific-gravity dust having a specific gravity higher than that of the first low-specific-gravity dust; and wet-gravity sorting the first high-specific-gravity dust, further comprising: when dismantling the scrapped vehicle, removing interior parts containing fiber, crushing the interior parts to obtain second shredded dust, and air-sorting the second shredded dust to obtain a second low-specific-gravity dust and a second high-specific-gravity dust having a specific gravity higher than that of the second low-specific-gravity dust.

[0009] (2) The resin recovery method according to (1), further comprising: separating the first high-specific-gravity dust by water gravity to obtain dust having a specific gravity of less than 1 and dust having a specific gravity of 1 or more.

[0010] (3) The method for recovering resin according to (2), wherein the dust having a specific gravity of less than 1 contains an olefin-based resin.

[0011] (4) The resin recovery method according to any one of (1) to (3), wherein, when obtaining the first shredded dust, the crushed scrapped vehicle body is magnetically separated to recover iron, and when obtaining the second shredded dust, the crushed interior parts are magnetically separated to recover iron.

[0012] (5) The resin recovery method according to any one of (1) to (4), further comprising a step of subjecting the first high-specific-gravity dust to metal separation to recover non-ferrous metals, and subjecting the first high-specific-gravity dust from which the metals have been separated to wet specific gravity separation.

[0013] (6) A resin recovery method according to any one of (1) to (5), wherein the air volume during the air sorting of the second shredder dust is greater than the air volume during the air sorting of the first shredder dust. Effect of the Invention

[0014] According to the present invention, it is possible to provide a resin recovery method capable of improving the recovery rate and recovery concentration of an olefin-based resin. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a diagram illustrating a resin recovery method according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating a resin recovery method according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram illustrating a resin recovery method according to an embodiment of the present invention. [Figure 4] 1 is a graph showing the relationship between the recovery rate of an olefin-based resin and the recovery concentration of the olefin-based resin in Example 1 and Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Specifically, a resin recovery method according to one embodiment of the present invention will be described with reference to Figs.

[0017] The resin recovery method of this embodiment is a method for recovering resin from a scrapped car 11. First, the scrapped car 11 is dismantled to obtain a scrapped car shell 12, and when the scrapped car 11 is dismantled, interior parts 13 containing fibers are removed (see FIG. 1). Here, the removed interior parts 13 are crushed separately from the scrapped car shell 12 as described below, so that the fiber content in the shredder dust obtained by crushing the scrapped car shell 12 is reduced. As a result, when the shredder dust is subjected to wind sorting, the amount of low specific gravity dust recovered is reduced, and the recovery rate and recovery concentration of the olefin resin are improved.

[0018] Here, if the scrapped car shell 12 is crushed without removing the interior parts 13, or if the removed interior parts 13 are crushed together with the scrapped car shell 12, the recovery rate or recovery concentration of the olefin resin will decrease as the amount of low-density dust containing entangled fibers increases when the shredder dust is air-sorted.

[0019] The interior parts 13 are not particularly limited as long as they contain fibers, and examples thereof include carpets, dash insulators, seats, roof linings, and trunk floors. Examples of fibers include, but are not particularly limited to, nonwoven fibers and pulp fibers. The fiber length of the fibers is, but is not particularly limited to, for example, 15 mm or more and 100 mm or less.

[0020] When dismantling the scrapped vehicle 11, for example, the prime mover, power train, suspension parts, audio, radiator, harness, etc. are also removed. In addition, before dismantling the scrapped vehicle 11, for example, refrigerant gas for the air conditioner, airbags, engine oil, transmission oil, cooling water, brake fluid, power steering fluid, fuel, and battery are collected.

[0021] The scrapped car body 12 contains, for example, iron, non-ferrous metals (copper, aluminum, etc.), resins (olefin-based resins, rubber, etc.), and glass, so resins are recovered from the scrapped car body 12 as follows (see FIG. 2).

[0022] First, the scrapped car body 12 is crushed, and then the crushed car body 12 is magnetically separated to recover the iron 21, and the first shredder dust 22 is obtained. Here, when the crushed car body 12 is magnetically separated, a known magnetic separator is used. Next, the first shredder dust 22 is air-separated to obtain the first low-specific-gravity dust 23 and the first high-specific-gravity dust 24 having a higher specific gravity than the first low-specific-gravity dust 23. Here, when the first shredder dust 22 is air-separated, a known air-separator is used. Next, the first high-specific-gravity dust 24 is metal-separated to recover the non-ferrous metals 25, and then the metal-separated first high-specific-gravity dust 24 is water-specific-gravity-separated to obtain the dust 26 having a specific gravity less than 1 and the dust 27 having a specific gravity of 1 or more. Here, when the first high-specific-gravity dust 24 is metal-separated, a known metal separator is used. Furthermore, when the first high-specific-gravity dust 24 after metal separation is subjected to water-specific-gravity separation, a known wet-type specific-gravity separator using water as a separation medium is used.

[0023] The dust 26 having a specific gravity of less than 1 contains an olefin resin, and the content of the olefin resin in the dust 26 having a specific gravity of less than 1 is preferably 95% by mass or more, and more preferably 98% by mass or more. When the content of the olefin resin in the dust 26 having a specific gravity of less than 1 is 95% by mass or more, the dust 26 having a specific gravity of less than 1 can be chemically recycled without being sorted.

[0024] Dust 27 having a specific gravity of 1 or more contains rubber.

[0025] If necessary, the step of recovering the iron 21 or the step of recovering the non-ferrous metals 25 may be omitted. Furthermore, if necessary, the first high-specific-gravity dust 24 from which metal has been separated may be subjected to wet specific gravity separation using a separating medium other than water.

[0026] On the other hand, since the interior parts 13 contain, for example, iron and resin (plastic, fiber, etc.), the resin is recovered from the interior parts 13 in the following manner (see FIG. 3).

[0027] First, the interior parts 13 are crushed, and then the crushed interior parts 13 are magnetically separated to recover the iron 31, thereby obtaining the second shredded dust 32. Here, a known magnetic separator is used to recover the iron 31. Next, the second shredded dust 32 is pneumatically separated to obtain the second low specific gravity dust 33 and the second high specific gravity dust 34 having a higher specific gravity than the second low specific gravity dust 33. Here, a known pneumatic separator is used to pneumatically separate the second shredded dust 32. The resin contained in the second low specific gravity dust 33 is depolymerized as necessary.

[0028] The air volume during air sorting of the second shredder dust 32 is preferably larger than the air volume during air sorting of the first shredder dust 22. This increases the amount of collected second low-specific-gravity dust 33, thereby improving the recovery rate of the resin contained in the second low-specific-gravity dust 33.

[0029] If necessary, the step of recovering iron 31 may be omitted.

[0030] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and the above embodiment may be modified as appropriate within the scope of the spirit of the present invention. EXAMPLES

[0031] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0032] [Example 1] Resin was recovered from one scrapped car by the resin recovery method shown in Figs. 1-3. At this time, when the scrapped car was dismantled, the carpet, dash insulator, seat, roof lining and trunk floor were removed as interior parts containing fibers. When the scrapped car was dismantled, the prime mover, power train, suspension parts, audio, radiator and harness were also removed. Before dismantling the scrapped car, refrigerant gas for the air conditioner, airbags, engine oil, transmission oil, cooling water, brake fluid, power steering fluid, fuel and battery were recovered. The air volume setting values ​​for air sorting the first shredder dust and the air volume setting values ​​for air sorting the second shredder dust were set to 170A and 220A, respectively. As a result, the recovered amounts of the first low specific gravity dust, dust with a specific gravity of less than 1, dust with a specific gravity of 1 or more and the second low specific gravity dust were 17kg, 26kg, 50kg and 34kg, respectively.

[0033] [Comparative Example 1] Except for crushing the removed interior parts together with the car body, resin was recovered from one scrapped car in the same manner as in Example 1. As a result, the recovered amounts of (first) low specific gravity dust, dust with a specific gravity of less than 1, and dust with a specific gravity of 1 or more were 140 kg, 5 kg, and 5 kg, respectively.

[0034] From the above, it can be seen that when dismantling an abandoned car, interior parts containing fibers are removed and crushed separately from the car body, and when the first shredder dust is air-sorted, the amount of first high-specific-gravity dust recovered decreases, while the amount of dust with a specific gravity of less than 1 and dust with a specific gravity of 1 or more recovered increases.

[0035] [Recovery concentration of olefin resin] The content of olefin resin in dust with a specific gravity of less than 1 was measured as follows, and used as the recovery concentration of olefin resin. First, the content of organic components in dust with a specific gravity of less than 1 was determined by elemental analysis (CHN analysis) and combustion ion chromatography (IC). Next, the content of olefin resin in the organic components was quantitatively analyzed by NMR.

[0036] [Recovery rate of olefin resin] The recovery rate of olefin-based resin was calculated based on the recovered amount of dust with a specific gravity of less than 1, the recovered concentration of olefin-based resin, and the amount of olefin-based resin used in the vehicle.

[0037] FIG. 4 shows the relationship between the recovery rate of the olefin resin and the recovery concentration of the olefin resin in Example 1 and Comparative Example 1.

[0038] It can be seen from FIG. 4 that Example 1 has a higher recovery rate and recovery concentration of the olefin resin than Comparative Example 1. [Explanation of symbols]

[0039] 11 Scrapped Vehicles 12 Scrapped Car Gala 13 Interior parts 21, 31 Iron 22 First Shredder Dust 23 First low density dust 24 First High Density Dust 25 Non-ferrous metals 26 Dust with specific gravity less than 1 27 Dust with specific gravity of 1 or more 32 Second Shredder Dust 33 Second low density dust 34 Second High Density Dust

Claims

1. A method for recovering resin from scrapped vehicles, comprising: A step of dismantling the scrapped car to obtain scrapped car shells; A step of shredding the scrapped vehicle body to obtain a first shredder dust; a step of wind-screening the first shredder dust to obtain a first low-specific-gravity dust and a first high-specific-gravity dust having a specific gravity higher than that of the first low-specific-gravity dust; and subjecting the first high specific gravity dust to wet specific gravity separation, When dismantling the scrapped vehicle, interior parts containing fibers are removed, shredding the interior parts to obtain second shredder dust; The resin recovery method further includes a step of wind-separating the second shredder dust to obtain a second low-specific-gravity dust and a second high-specific-gravity dust having a specific gravity higher than that of the second low-specific-gravity dust.

2. 2. The method for recovering resin according to claim 1, further comprising: separating the first high specific gravity dust by water gravity to obtain dust having a specific gravity of less than 1 and dust having a specific gravity of 1 or more.

3. The resin recovery method according to claim 2 , wherein the dust having a specific gravity of less than 1 contains an olefin-based resin.

4. When obtaining the first shredder dust, the crushed scrap car body is subjected to magnetic separation to recover iron; The resin recovery method according to claim 1 , further comprising the step of: recovering iron by magnetically separating the shredded interior parts when obtaining the second shredder dust.

5. The method further comprises a step of separating the first high specific gravity dust into metals to recover non-ferrous metals, The resin recovery method according to claim 1 , further comprising the step of subjecting the first high-specific-gravity dust after the metal separation to wet specific gravity separation.

6. The resin recovery method according to claim 1 , wherein an air volume during the air separation of the second shredder dust is greater than an air volume during the air separation of the first shredder dust.

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