Recycling methods

Abstract

According to the present invention, a recycling method is provided for recovering metal from articles having fastening articles (40, 50, 80) containing metal parts. The recycling method includes: a crushing step (14, 34) of crushing at least a portion of the metal parts; and a sorting step of separating fragments containing a specific metal from the crushed material obtained through the crushing step (14, 34). Thus, the target metal can be recovered from articles having fastening articles (40, 50, 80) in a manner that reduces the concentration of impurities such as iron and aluminum.

Description

Technical Field

[0001] This invention relates to a method for recycling metal from articles having fasteners containing metal parts, or zipper pulls or articles having pulls. Background Technology

[0002] As a technology for effectively utilizing resources, for example, Japanese Patent Application Publication No. 2018-140329 (Patent Document 1) and Japanese Patent Application Publication No. 2019-089037 (Patent Document 2) describe clothing recycling devices and methods.

[0003] In the technology described in Patent Documents 1 and 2, for clothing with decorative parts such as zippers, the process involves sequentially heating to embrittle the fabric portion of the clothing, crushing to separate the fabric portion from the decorative parts, and sorting to separate low-density materials containing fabric from high-density materials containing metal. This allows for the heat recovery and reuse of the low-density material as fuel, and the recovery and reuse of valuable metals contained in the high-density material.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-140329

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-089037 Summary of the Invention

[0008] In the technologies described in Patent Documents 1 and 2, valuable metals can be recycled from clothing with decorative parts, thus effectively utilizing resources. However, it is difficult to recycle the target metal at a high content. Furthermore, in metal recycling, if the reduction of CO2 emissions is taken into consideration, it would be more effective to remelt the recycled metal and directly form the target component or part.

[0009] However, in the technologies described in Patent Documents 1 and 2, for example, when components such as pull heads or rivets are used as fastening products, it is difficult to remelt the recycled metal to stably obtain components for fastening products because the recycled metal is prone to contain a large number of impurities.

[0010] For example, stainless steel components are sometimes used for zipper pulls. However, when metals (such as copper alloys) from such stainless steel zipper pulls are recycled and used to form components for fasteners, the Fe concentration in the metal forming the component becomes high. As a result, when fasteners made of metals with high Fe concentrations are attached to clothing or other items, they are more likely to cause a reaction in the needle detector when the item passes through it.

[0011] Furthermore, aluminum is often used for rivets, which are fasteners. However, when metals such as copper alloys are recycled from rivet-containing components to form fasteners, aluminum is mixed into the recycled metal, which negatively affects the casting and machinability of the components.

[0012] Therefore, the object of the present invention is to provide a recycling method that can recycle target metals from clothing and other articles having fasteners such as zippers or rivets in a manner that reduces the concentration of impurities such as iron and aluminum.

[0013] To achieve the above objectives, the recycling method of the first aspect provided by the present invention is a recycling method for recycling metal from articles having fasteners containing metal parts, characterized in that it includes: a crushing step of crushing at least a portion of the metal parts; and a sorting step of sorting the crushed material obtained by the crushing step into fragments containing specific metals.

[0014] Preferably, the recycling method of the first aspect of the present invention includes magnetic sorting in the above-mentioned sorting process.

[0015] Preferably, the recycling method of the present invention includes a heat treatment step of heat-treating the article prior to the above-mentioned crushing step and separating the metal parts of the fastening article from the fibrous part.

[0016] In this case, it is preferable that the recycling method includes carbonization treatment in the above-mentioned heat treatment process to partially carbonize the fiber, and remelting the metal separated in the above-mentioned sorting process.

[0017] In addition, preferably, the recycling method involves sieve-based sorting after the heat treatment process and before the crushing process.

[0018] The recycling method of the second aspect provided by the present invention is a recycling method for recycling metal contained in a zipper pull or an article having the zipper pull, characterized in that it includes: a crushing step of at least crushing the zipper pull; and a sorting step of separating fragments containing a specific metal from the crushed material obtained by the crushing step.

[0019] Preferably, the recycling method of the second aspect of the present invention includes magnetic sorting in the above-mentioned sorting process.

[0020] Preferably, the recycling methods of the first and second aspects of the present invention include repeatedly applying high-energy impacts to the metal parts or the pull head during the crushing process.

[0021] Furthermore, preferably, the recycling methods of the first and second embodiments of the present invention include recycling at least one of copper alloys, stainless steel, aluminum and zinc as the aforementioned metals.

[0022] Invention Effects

[0023] According to the present invention, a recycling method is provided that can recover target metals from clothing and other articles having fastening products such as zippers and rivets in a manner that reduces the concentration of impurities such as iron and aluminum. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating the recycling method according to the first embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram illustrating the recycling method of the first embodiment.

[0026] Figure 3 This is a schematic diagram illustrating a chain crusher used in the crushing process of a recycling method.

[0027] Figure 4 This is a flowchart illustrating the recycling method according to the second embodiment of the present invention.

[0028] Figure 5 This is a schematic diagram illustrating the recycling method of the second embodiment.

[0029] Figure 6 This is a flowchart illustrating the recycling method according to the third embodiment of the present invention.

[0030] Figure 7 This is a schematic diagram illustrating the recycling method of the third embodiment. Detailed Implementation

[0031] The following is a reference to the appendix. Figure 1 The preferred embodiments of the present invention will be described in detail below.

[0032] Furthermore, in this invention, fastening products include zippers with at least left and right zipper teeth and zipper pulls, rivets, snaps, buckles, cord locks, belt adjusters, swivels, and other products. Among such fastening products, fastening products containing metal parts (metal components), or clothing and other items with such fastening products installed, become objects for metal recycling.

[0033] Furthermore, in this invention, articles having fastening components and articles having zipper pulls include clothing such as clothes and jeans, bags, daily necessities, and fabrics used therein. For example, in the first embodiment below, the case of recycling metal from jeans with zippers and rivets having metal parts is described; in the third embodiment, the case of recycling metal from clothing fabric with zippers having metal parts is described; however, in this invention, metal can also be recycled from other articles (preferably fiber products) with fastening components containing metal parts.

[0034] (First Embodiment)

[0035] Figure 1 This is a flowchart illustrating the recycling method in the first embodiment. Figure 2 This is a schematic diagram illustrating the recycling method in the first embodiment.

[0036] In the first embodiment, a case is described in which copper alloy, aluminum and stainless steel are extracted from jeans with zippers 40 and rivets 50 having metal parts and reused.

[0037] First, before starting the recycling process, jeans with zippers 40 and multiple rivets 50 installed are prepared in advance, as items with fastenings that are subject to recycling. Figure 1 Preparation 11).

[0038] In this case, such as Figure 2 As schematically shown, the zipper 40 has: a pair of left and right zipper teeth straps on the zipper strap 41 to form a tooth row by mounting copper alloy zipper teeth 42 on the zipper strap 41; a zipper pull 43 that is slidably mounted on the tooth row; and a first copper alloy stop (upper stop) 44 and a second copper alloy stop (lower stop) 45 respectively disposed adjacent to one end and the other end of the tooth row.

[0039] The zipper 40 uses a zipper head 43 with at least a copper alloy zipper head body 43a and a zipper tab 43b, and a stainless steel locking pin (stop claw) 43c used in the locking mechanism (stop mechanism) of the zipper head 43.

[0040] Furthermore, the pull head 43 is formed in a small size and is integrally assembled into the component by performing plastic deformation processing (compression processing) on ​​at least a portion of the aforementioned components. Such a pull head 43 is difficult to crush using hammer crushers, which are conventionally known as crushing methods. In addition, when using a crushing device with rotating crushing blades to crush the pull head 43, there is a problem that the crushing blades are prone to wear.

[0041] Each rivet 50 has at least an aluminum rivet core 51 that has undergone plastic deformation processing, and a copper alloy rivet cap 52 that covers a portion of the rivet core 51. Furthermore, the rivets 50 are integrally mounted to the denim fabric after at least a portion of the component has undergone plastic deformation processing, etc.

[0042] Alternatively, in the preparation of the jeans 11, the jeans can be cut into several parts, such as the part with the zipper 40 on the denim fabric, the part with the rivets 50 on the denim fabric, and the part that is only denim fabric 60. Alternatively, the jeans can be prepared without being cut and left in their original state.

[0043] Next, a heat treatment process (carbonization process) 12 is carried out on the prepared jeans to perform heat treatment (carbonization process in the first embodiment).

[0044] In this heat treatment step 12, the prepared jeans are heated, for example, in a superheated steam environment at a temperature of 300°C to 600°C, causing the fibrous parts of the zipper tape 41 and denim fabric 60 to carbonize. As a result, the shape of the zipper tape 41 and the shape of the denim fabric 60 are destroyed, the fibrous parts are scattered into small pieces, and the metal parts such as the zipper teeth 42, the zipper pull 43, the first stop 44, the second stop 45, and the rivets 50, which are directly or indirectly attached to the zipper tape 41 and the denim fabric 60, can be separated from the fibrous parts and disassembled.

[0045] Furthermore, carbonization processes can be used to obtain carbonized materials 60a of denim fabric 60 and 41a of zipper tape 41 from the fiber portions of denim fabric 60 and zipper tape 41, respectively. These carbonized materials 60a and 41a can be used as reducing agents in the copper alloy remelting process 17 described later.

[0046] By using carbides 60a and 41a as reducing agents, zinc oxidation can be suppressed in the remelting process 17, thereby improving the yield of various components (e.g., zipper teeth 42, zipper pull body 43a, pull tab 43b, rivet cover 52, etc.) of the fasteners produced from the remelting process 17.

[0047] Furthermore, in the case where carbonization is performed in heat treatment step 12 as in the first embodiment, heating can also be performed in a gaseous environment of natural gas or an inert gas instead of superheated steam. Additionally, in this invention, instead of carbonization, heat treatment step 12 can be performed by combustion treatment, which burns the fibrous portions of the denim fabric 60, etc. By performing this combustion treatment, the fibrous portions of the denim fabric 60, etc., can be burned off and removed, thereby allowing the aforementioned metal parts to be separated and disassembled.

[0048] After the heat treatment process 12 is completed, a sieve-based sorting process (first sorting process) 13 is performed on the various metal parts 42, 43, 44, 45, 50 and carbides 60a, 41a that were disassembled in the heat treatment process 12. As a result, the carbides 60a of the large denim fabric 60, the zipper pull 43 and the rivets 50, etc., and the carbides 41a of the small zipper tape 41, the zipper teeth 42, the first stop 44 and the second stop 45, etc., are separated.

[0049] As a result, since only the zipper teeth 42, the first stop 44, and the second stop 45 made of copper alloy can be separated and recycled from metal parts such as the zipper pull 43, which also contain other metals, it is possible to recycle copper alloys with low iron and aluminum content.

[0050] For example, in the first embodiment, by remelting the zipper teeth 42, the first stop 44, and the second stop 45 separated in the screen-based sorting process 13, a new target component or member made of copper alloy, such as a component used in fasteners, can be formed. As a result, the effect of effectively utilizing resources and reducing CO2 emissions can be achieved. Furthermore, in this invention, the screen-based sorting process 13 can also be omitted.

[0051] On the other hand, large components and parts such as carbonized material 60a, zipper pulls 43, and rivets 50 of the denim fabric 60 separated in the screen-based sorting process 13 are conveyed to the crushing process 14 for crushing processing using a crusher 70. In the first embodiment, the crusher 70 is a... Figure 3 The chain crusher 70 shown is, for example, Cross Flow Shredder (trade name), manufactured by Sato Iron Works Co., Ltd.

[0052] Figure 3The chain crusher 70 shown includes: a crushing chamber 71 formed in a cylindrical shape; a chain fixing part 72 rotatably disposed on the bottom surface of the crushing chamber 71; a plurality of chains 73 with one end fixed to the chain fixing part 72; and a drive part (not shown) that drives the chain fixing part 72 to rotate. In this chain crusher 70, by housing the carbonized material 60a of denim fabric 60 (the object to be crushed), the pull head 43, and the rivets 50, etc., inside the crushing chamber 71 and sealing the crushing chamber 71, the chain fixing part 72 is rotated at high speed, so that the object to be crushed and the chain 73 collide repeatedly, and the object to be crushed also collide repeatedly with each other.

[0053] In the first embodiment, the slider body 43a and slider tab 43b of the slider 43 and the rivet cap 52 of the rivet 50, which are crushed in the crushing process 14, are made of, for example, a copper alloy, which is known to be a metal with excellent ductility and relatively easy deformation. Therefore, in the first embodiment, in order to crush such a copper alloy metal part, high-energy impacts are repeatedly applied to the metal parts such as the slider 43 and the rivet 50. For example, high-speed impacts and impacts with heavy objects are repeatedly applied as high-energy impacts. As a result, the copper alloy metal part can be work-hardened, making the metal part brittle, and as a result, the copper alloy metal part can be crushed properly.

[0054] In the first embodiment, by performing the crushing process 14, the slider 43 can be separated into slider body 43a, slider tab 43b, and locking pin 43c, and each component can be crushed into smaller fragments. Similarly, the rivet 50 can be separated into rivet core 51 and rivet cover 52, and each can be crushed into smaller fragments. For example, in the case of the first embodiment, the crushing process 14 can crush each metal component into fragments of approximately 3mm to 5mm.

[0055] Therefore, the shredded material obtained after the crushing process 14 includes copper alloy shreds obtained from crushing the pull head body 43a, pull tab 43b and rivet cover 52, stainless steel shreds obtained from crushing the locking pin 43c, aluminum shreds obtained from crushing the rivet core 51, and carbides 60a of denim fabric 60.

[0056] Furthermore, in the first embodiment, each component of the zipper head body 43a, zipper tab 43b, locking pin 43c, rivet core 51, and rivet cover 52 is actually broken into multiple small-sized fragments as described above through the crushing process 14, but... Figure 2 In order to easily illustrate the features of the first embodiment, the state of each component being broken is shown not as broken pieces but as retaining its original shape (as described later). Figure 5 and Figure 7 (The same applies to the middle). In addition, the crushing process 14 of the present invention is only required to crush the pull head 43 and the rivet 50 into individual component units. The processing conditions of the crushing process 14 and the size of the fragments obtained in the crushing process 14 are not particularly limited.

[0057] The crushed material obtained by crushing step 14 is then conveyed to magnetic separation step (second separation step) 15. In this magnetic separation step 15, stainless steel fragments (fragments with locking pin 43c) are separated and recovered from the crushed material using magnetic force.

[0058] More specifically, in the magnetic separation process 15 of the first embodiment, a first magnetic separation process is performed in sequence to remove magnetic metals such as iron sheets by magnetic separation, and a second magnetic separation process is performed to separate and recover the broken pieces of the stainless steel locking pin 43c, which is a weakly magnetic body, by applying a magnetic field higher than that of the first magnetic separation process.

[0059] First, by performing a first magnetic separation process based on a common magnetic field, the risk of foreign matter such as iron fragments being mixed in when recovering stainless steel fragments using a high magnetic field-based magnetic separation process can be reduced. Then, by performing a second magnetic separation process based on a high magnetic field on the fragments that have undergone the first magnetic separation process, stainless steel fragments (fragments of lock pin 43c) can be effectively recovered and reused or sold.

[0060] On the other hand, in the crushed material from which magnetic metals and stainless steel have been removed through the magnetic separation process 15, materials containing, for example... Figure 2 The copper alloy fragments obtained by breaking the zipper head body 43a, zipper tab 43b and rivet cover 52 as shown, the aluminum fragments obtained by breaking the rivet core 51, and the carbide 60a of denim fabric 60.

[0061] After the magnetic separation process 15, the remaining fragments undergo a wet gravity separation process (third separation process) 16. This wet gravity separation process 16 allows for the separation and separate recycling of copper alloy fragments obtained from breaking the zipper head body 43a, zipper tab 43b, and rivet cover 52; aluminum fragments obtained from breaking the rivet core 51; and carbides 60a from the denim fabric 60. Furthermore, in cases where fragments were not separated in this wet gravity separation process 16, further wet gravity separation with altered separation conditions can be performed on these fragments to separate each target material.

[0062] The aluminum fragments (fragments of rivet core 51) recovered in the wet gravity separation process 16 can be reused or sold. The copper alloy fragments, by being conveyed to the remelting process 17 and remelted, can be used to form new copper alloy components or parts for use in fasteners. This effectively utilizes resources and reduces CO2 emissions, thus significantly contributing to the achievement of the SDGs (Sustainable Development Goals). The carbide 60a can be used as a reducing agent in the copper alloy remelting process 17.

[0063] Furthermore, in the first embodiment, by replacing the wet gravity separation process 16 described above with separation methods such as wind separation, wind-driven shaking table separation, and heavy liquid separation, it is also possible to separate and recover the target metal from the crushed material obtained after the magnetic separation process 15.

[0064] According to the recycling method in the first embodiment described above, stainless steel, aluminum, and copper alloys can be separated and recycle stably from jeans with the aforementioned zipper 40 and rivets 50. In particular, regarding the copper alloy, copper alloys with low concentrations of impurities such as stainless steel and aluminum can be recycle stably. For example, in the first embodiment, the Fe concentration and Al concentration in the recycled copper alloy can both be 500 ppm or less, preferably 300 ppm or less.

[0065] Therefore, for example, when using recycled copper alloys to manufacture fasteners, it is possible to prevent the needle detector from reacting due to the copper alloy when clothing or other items with the fasteners attached are passed through the needle detector. Furthermore, it is possible to suppress the reduction in the castability and machinability of components used in the fasteners caused by aluminum in the copper alloy.

[0066] Furthermore, in the first embodiment, by partially carbonizing the fibers to recover the carbides 60a and 41a, they can be used as reducing agents in the copper alloy remelting process 17 as described above, thus enabling more efficient use of resources. Additionally, it also improves the yield rate of parts or components obtained from the remelting process 17.

[0067] Furthermore, in the first embodiment, for example, if the item to be recycled is an item that does not contain rivets 50 or similar items with aluminum components, the wet gravity separation process 16, which separates and recycles aluminum fragments, can be omitted. In this case, since the shredded material obtained after the magnetic separation process 15 contains only copper alloy fragments, the copper alloy fragments can be easily recycled and reused.

[0068] (Second Implementation)

[0069] Figure 4 This is a flowchart illustrating the recycling method in the second embodiment. Figure 5 This is a schematic diagram illustrating the recycling method in the second embodiment.

[0070] In the second embodiment, the case in which only the zipper pull 43 is recycled and the copper alloy and stainless steel are extracted from the zipper pull 43 and reused is described.

[0071] First, prepare in advance the 43rd pull head that will be used for recycling. Figure 4 Preparation 21). The zipper pull 43 is formed in essentially the same way as the zipper pull 43 included in the zipper 40 of the first embodiment described above. That is, the zipper pull 43 in the second embodiment has at least a copper alloy zipper pull body 43a, a pull tab 43b, and a stainless steel locking pin 43c. In addition, regarding the zipper pull 43, at least a portion of the component is subjected to plastic deformation processing (pressing processing) during component assembly.

[0072] Next, the prepared slider head 43 undergoes a crushing process 22. In this crushing process 22, similar to the first embodiment described above, a crushing process based on... Figure 3 The crushing process of the crusher 70 shown. By performing this crushing process 22, the pull head 43 can be separated into the pull head body 43a, the pull plate 43b, and the locking pin 43c, and each component can be crushed into smaller pieces.

[0073] The crushed material obtained by crushing the material with the pull head 43 in the crushing process 22 is then conveyed to the magnetic separation process 23. In this magnetic separation process 23, similar to the case of the first embodiment described above, a first magnetic separation process is performed to remove magnetic metals by magnetic separation, and a second magnetic separation process is performed to separate and recover stainless steel fragments by applying a magnetic field higher than that of the first magnetic separation process.

[0074] This allows for the efficient recycling of stainless steel fragments (fragments of lock pin 43c) for reuse or sale.

[0075] Furthermore, in the crushed material from which magnetic metals and stainless steel have been removed through the magnetic separation process 23, only materials containing, such as Figure 5 The copper alloy fragments are obtained by crushing the pull head body 43a and pull tab 43b as shown. Therefore, the copper alloy fragments can be easily recycled, and the recycled copper alloy fragments can be sent to the remelting process 24 for remelting. As a result, new copper alloy target parts or components, such as parts used in fasteners, can be formed.

[0076] As described above, according to the recycling method in the second embodiment, even from the pull head 43 alone, stainless steel and copper alloy can be separated as individual metals and recycled stably.

[0077] (Third Implementation)

[0078] Figure 6 This is a flowchart illustrating the recycling method in the third embodiment. Figure 7 This is a schematic diagram illustrating the recycling method in the third embodiment.

[0079] In the third embodiment, a case is described in which zinc, copper alloy and stainless steel are extracted from clothing with a zipper 80 having metal parts and reused.

[0080] First, before starting the recycling process, prepare the garment (80) with a zipper containing metal parts beforehand, as it is to be recycled. Figure 6 Preparation 31).

[0081] In this case, such as Figure 7 As schematically shown, the zipper 80 has: a pair of left and right zipper teeth straps on the zipper strap 81, which are formed by mounting copper alloy zipper teeth 82 on the zipper strap 81; a zipper pull 83 that is slidably mounted on the zipper teeth; a copper alloy stop (upper stop) 84 disposed adjacent to one end of the zipper teeth; and a zinc separation insert 85 disposed adjacent to one end of the zipper teeth.

[0082] The zipper pull 83 used in the zipper 80 has at least: a zinc zipper pull body 83a and a pull tab 83b; a stainless steel locking pin 83c used in the locking mechanism of the zipper pull 83; and a copper alloy cover 83d covering a portion of the pull tab 83b and the locking pin 83c. The zipper pull 83 is formed in a small size and is integrally assembled by performing plastic deformation processing (pressing processing) or the like on at least a portion of the above-mentioned components.

[0083] In this preparation 31, the clothing with the zipper 80 installed (the object to be recycled) can also be divided into parts of the clothing fabric 61 with the zipper 80 installed and parts that are just clothing fabric 61, for example, by cutting. In addition, the clothing can also be prepared in its original state as clothing.

[0084] Next, the prepared garments are transported to the heat treatment process (carbonization process) 32 for heat treatment (carbonization treatment).

[0085] By performing carbonization in the heat treatment step 32, the fibrous parts such as the zipper tape 81 and the clothing fabric 61 can be carbonized and randomly separated into small pieces, and the metal components such as the zipper teeth 82, the zipper pull 83, the stop 84, and the release insert 85 can be separated from the fibrous parts. In addition, using the heat of the carbonization treatment, the zinc zipper pull body 83a, the zipper tab 83b, and the release insert 85 are melted, and the molten zinc is cooled, thereby forming a zinc block 86 integrating the zinc and several components. Moreover, carbides 81a and 61a, which are fibrous parts, can be obtained from the zipper tape 81 and the clothing fabric 61, which can be used as a reducing agent in the remelting process.

[0086] After heat treatment step 32, a sieve-based sorting step 33 is performed on the various metal parts and carbides 81a and 61a obtained in heat treatment step 32, separating the carbides 61a and zinc blocks 86 of the large-sized clothing fabric 61 from the carbides 81a of the zipper tape 81 that are not integrated with the zinc blocks 86, the zipper teeth 82, the stop 84, and the cover 83d of the zipper pull 83 (in addition, in Figure 7 An example is shown where the cover 83d of the zipper pull 83 is integrated with the zinc block 86. Thus, only the copper alloy zipper teeth 82, the stop 84, and the cover 83d can be recycled, resulting in the recycling of copper alloys with low iron content.

[0087] Furthermore, in this invention, the sieve-based sorting process 33 can also be omitted.

[0088] The large-sized components and portions of the clothing fabric 61, such as carbides 60a and zinc blocks 86, separated in the screen-based sorting process 33 are then conveyed to the crushing process 34, where, similar to the first embodiment described above, they are subjected to a screen-based sorting process. Figure 3 The crushing process of the crusher 70 shown. By performing this crushing step 34, the carbides 61a of the clothing fabric 61 can be crushed and reduced to smaller sizes. In addition, the zinc ingot 86 can be crushed to form small zinc fragments 87, and the various metal parts and carbides integrated with the zinc ingot 86 can be separated, thereby further crushing the separated metal parts and carbides into smaller sizes.

[0089] The crushed material obtained after the crushing process 34 includes zinc-made crushed pieces 87, stainless steel-made crushed pieces obtained by crushing the locking pin 83c, copper alloy-made crushed pieces obtained by crushing the zipper teeth 82 and cover 83d integrated with the zinc block 86, and carbides 61a and 81a of clothing fabric 61 and zipper tape 81.

[0090] The crushed material obtained by the crushing process 34 is then conveyed to the magnetic separation process 35. In this magnetic separation process 35, similar to the first embodiment described above, a first magnetic separation process is performed to separate and remove magnetic metals, and a second magnetic separation process is performed to separate and recover the stainless steel fragments, which are weakly magnetic materials, by applying a magnetic field higher than that of the first magnetic separation process. Thus, it is possible to efficiently recover the stainless steel fragments (fragments of the locking pin 83c) for reuse or sale.

[0091] In addition, in the crushed material where magnetic metals and stainless steel have been removed through the magnetic separation process 35, such as Figure 7 As shown, it includes zinc-made fragments 87, copper alloy fragments obtained by breaking zipper teeth 82 and cover 83d, and carbides (not shown).

[0092] Next, in the third embodiment, a grading process 36 is performed on the remaining fragments after the magnetic separation process 35. By performing this grading process 36, the fragments can be divided into multiple groups according to their size and shape. For example, in the grading process 36 of the third embodiment, the fragments after the magnetic separation process 35 are sorted based on a screen into a first group 91 with large fragments, a second group 92 with medium-sized fragments, and a third group 93 with small fragments.

[0093] By dividing the crushed material into three grades according to the size and shape of the fragments, and matching the size and shape of the fragments for each group, zinc and copper alloys with small differences in specific gravity can be easily separated, thereby improving the separation rate of zinc and copper alloys. For example, the larger zinc fragments 87 obtained from crushing zinc blocks 86 are collected in the first group 91, which has larger sizes. Therefore, it is easy to recover and reuse only the zinc fragments 87.

[0094] Additionally, in the second group 92 of moderate size, zinc fragments 87 obtained from crushing the zinc block 86, copper alloy fragments obtained from crushing the zipper teeth 82 and the cover 83d, and carbides are collected. In this case, by performing a sorting process such as the wet gravity separation process 16 performed in the first embodiment described above on the fragments collected in the second group 92, the zinc fragments 87, copper alloy fragments, and carbides can be separated and recycled separately.

[0095] In addition, the recycled copper alloy fragments, being copper alloys with low concentrations of impurities such as stainless steel and aluminum and high purity, can be remelted in a remelting process to form new parts or components for use in fasteners.

[0096] In the smaller third group 93, zinc-based fragments 87 are mainly collected, thus allowing for the recycling and reuse of the zinc-based fragments 87. Furthermore, in the case where the fragments collected in the third group 93 contain a large amount of copper alloy fragments and carbides in addition to zinc-based fragments 87, similar to the case of the second group 92, further sorting processes such as wet gravity separation can separate and separately recycle the zinc-based fragments 87, copper alloy fragments, and carbides.

[0097] As described above, according to the recycling method in the third embodiment, stainless steel, zinc, and copper alloys can be separated and recycle stably from clothing with zippers 80 containing metal parts, respectively. Furthermore, by carbonizing the fiber portion and recovering the carbides 61a and 81a, they can be used as reducing agents in processes such as the remelting of copper alloys, thus enabling more efficient resource utilization and improving the yield rate of parts or components obtained from the remelting process.

[0098] Example

[0099] The present invention will now be described in more detail with reference to examples and comparative examples.

[0100] As an example, the recycling method described in the first embodiment above is used, and brass, aluminum, and stainless steel, which are among the copper alloys, are separated and recycled from jeans with zippers 40 and rivets 50 having metal parts. In this case, the zippers 40 and rivets 50 installed on the jeans, which are the objects of recycling, are formed as described in the first embodiment.

[0101] In another embodiment, the Fe concentration in the copper alloy was investigated by dissolving the fragments of the copper alloy recovered after the wet gravity separation process 16 and performing quantitative analysis based on high-frequency inductively coupled plasma optical emission analysis (ICP-OES).

[0102] On the other hand, as a comparative example, jeans identical to those in the embodiment were prepared, and the jeans were subjected to the heat treatment process (carbonization process) 12 described in the first embodiment. The metal parts obtained after the heat treatment process 12 were recovered. In addition, in the comparative example, the Fe concentration in the metal was investigated by dissolving all the recovered metal parts and performing quantitative analysis based on ICP-OES.

[0103] The Fe concentration was investigated for the copper alloy recovered in the examples and the metal recovered in the comparative examples. The results confirmed that the Fe concentration in the copper alloy recovered in the examples was 180 ppm, which is lower than the Fe concentration specified in the JIS standard for copper alloys (C2100 to C2700). On the other hand, it was found that the Fe concentration in the metal recovered in the comparative examples was as high as 1000 ppm.

[0104] Explanation of reference numerals in the attached figures

[0105] 11 Preparation

[0106] 12. Heat treatment process (carbonization process)

[0107] 13. Screen-based sorting process (Separation Process 1)

[0108] 14 Crushing process

[0109] 15. Magnetic sorting process (second sorting process)

[0110] 16. Wet gravity separation process (3rd separation process)

[0111] 17 Remelting process

[0112] 21 Preparation

[0113] 22 Crushing process

[0114] 23 Magnetic sorting process

[0115] 24 Remelting process

[0116] 31 Preparation

[0117] 32. Heat treatment process (carbonization process)

[0118] 33 Screen-based sorting process

[0119] 34 Crushing process

[0120] 35. Magnetic sorting process

[0121] 36 Grading process

[0122] 40 Zippers

[0123] 41 Zipper Tape

[0124] 41a carbides

[0125] 42 Zipper teeth

[0126] 43 Pull-out

[0127] 43a Slider head body

[0128] 43b Film Pull

[0129] 43c Locking pin (stop claw body)

[0130] 44 No. 1 stop (top stop)

[0131] 45 2nd stop (lower stop)

[0132] 50 rivets

[0133] 51 Rivet core

[0134] 52 Rivet cover

[0135] 60 Denim Fabric

[0136] 60a carbide

[0137] 61. Clothing and fabric

[0138] 61a carbide

[0139] 70 Crusher

[0140] 71 Crushing Chamber

[0141] 72 Chain fixing part

[0142] 73 Chains

[0143] 80 Zipper

[0144] 81 Zipper Tape

[0145] 81a carbide

[0146] 82 Zipper teeth

[0147] 83 Pull-out

[0148] 83a Slider Head Body

[0149] 83b film pull

[0150] 83c locking pin

[0151] 83d cover

[0152] 84 Stop (top stop)

[0153] 85 Separate Embedded Plug-in

[0154] 86 Zinc blocks

[0155] 87 Zinc-plated shredded metal

[0156] 91 Group 1

[0157] 92 Group 2

[0158] 93 Group 3.

Claims

1. A recycling method for recovering metal from articles having fasteners (40, 50, 80) containing metal parts, the recycling method being characterized by comprising: A crushing process (14, 34) in which at least a portion of the metal parts are crushed. as well as A sorting process for separating fragments containing specific metals from the crushed material obtained through the crushing processes (14, 34). The crushing process (14, 34) includes: using a crusher (70) with multiple chains (73) to repeatedly collide the crushed material with the chains (73) and to repeatedly collide the crushed material with each other, thereby causing work hardening of the copper alloy metal parts.

2. The recycling method as described in claim 1, characterized in that, This includes magnetic sorting in the sorting process.

3. The recycling method as described in claim 1, characterized in that, The heat treatment process (12, 32) includes heat treatment of the article prior to the crushing process (14, 34) and separation of the metal parts of the fastening articles (40, 50, 80) from the fibrous portion.

4. The recycling method as described in claim 2, characterized in that, The heat treatment process (12, 32) includes heat treatment of the article prior to the crushing process (14, 34) and separation of the metal parts of the fastening articles (40, 50, 80) from the fibrous portion.

5. The recycling method as described in claim 3, characterized in that, include: In the heat treatment process (12, 32), a carbonization treatment is performed to carbonize the fiber portion by heating in a gaseous environment of superheated steam, natural gas, or inactive gas to obtain a carbonized material. The metals sorted in the sorting process are then remelted in the remelting process; and In the remelting process, the carbide obtained in the carbonization treatment is used as a reducing agent.

6. The recycling method as described in claim 4, characterized in that, include: In the heat treatment process (12, 32), a carbonization treatment is performed to carbonize the fiber portion by heating in a gaseous environment of superheated steam, natural gas, or inactive gas to obtain a carbonized material. The metals sorted in the sorting process are then remelted in the remelting process; and In the remelting process, the carbide obtained in the carbonization treatment is used as a reducing agent.

7. The recycling method according to any one of claims 3 to 6, characterized in that, This includes sieve-based sorting after the heat treatment process (12, 32) and before the crushing process (14, 34).

8. The recycling method according to any one of claims 1 to 6, characterized in that, This includes repeatedly applying high-energy impacts to the metal components during the crushing processes (14, 34).

9. The recycling method as described in claim 7, characterized in that, This includes repeatedly applying high-energy impacts to the metal components during the crushing processes (14, 34).

10. The recycling method according to any one of claims 1 to 6 and 9, characterized in that... This includes at least one of copper alloys, stainless steel, aluminum, and zinc that are recycled as said metal.

11. The recycling method as described in claim 7, characterized in that... This includes at least one of copper alloys, stainless steel, aluminum, and zinc that are recycled as said metal.

12. The recycling method as described in claim 8, characterized in that... This includes at least one of copper alloys, stainless steel, aluminum, and zinc that are recycled as said metal.

13. A recycling method for recovering metal contained in a zipper pull (43) or an article having said zipper pull (43), the recycling method being characterized by comprising: At least the crushing process (22) that breaks the pull head (43); and A sorting process for separating fragments containing specific metals from the crushed material obtained through the crushing process (22). The crushing process (22) includes: using a crusher (70) with multiple chains (73) to repeatedly collide the crushed material with the chains (73) and to repeatedly collide the crushed material with each other, thereby causing work hardening of the copper alloy metal parts.

14. The recycling method as described in claim 13, characterized in that, This includes magnetic sorting in the sorting process.

15. The recycling method as described in claim 13, characterized in that, This includes repeatedly applying high-energy impacts to the feed head (43) during the crushing process (22).

16. The recycling method as described in claim 14, characterized in that, This includes repeatedly applying high-energy impacts to the feed head (43) during the crushing process (22).

17. The recycling method according to any one of claims 13 to 16, characterized in that... This includes at least one of copper alloys, stainless steel, aluminum, and zinc that are recycled as said metal.

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