How to process solar cell modules

Abstract

To simply process the recovery of valuable metals from a solar battery module and that of different resin components through separating by kind.SOLUTION: This invention is a method for processing a solar cell module having: a preparation process of preparing a solar battery cell sheet-like structure, which comprises, on removal of a glass substrate and a frame member from a solar battery module, at least a solar cell, a metal pattern wired from the solar battery cell, a resin-made encapsulation member that encapsulates these, and a resin-made protective member provided on one face of the encapsulation member; a crushing process of crushing the solar battery sheet-like structure to form a crushed matter including particulate matters derived from each member; and a separation process of making the crushed matter undergo electrostatic selection and wind power selection to separate the respective particulate matters for each kind of metal and resin.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for treating a solar cell module. [Background technology]

[0002] Solar cell power generation is drawing attention as a renewable energy source because it utilizes clean energy, namely sunlight, and has a small environmental impact. A solar cell module used in this solar cell power generation is configured, for example, with a glass substrate, a sealant that seals the solar cell, a protective member (a so-called back sheet), a metal pattern that is wired from the solar cell, and a frame member that is provided around the sealant.

[0003] Until now, solar cell modules have been disposed of after a certain period of use, but in recent years, there has been a demand for recycling, and the recovery of valuable metals, such as copper and silver contained in the metal pattern, has become necessary.

[0004] In view of this, as a method for recovering valuable metals from solar cell modules, for example, Patent Document 1 has been disclosed. Patent Document 1 proposes a method for recovering solar cell cells after heating the solar cell module to remove the sealing material and protective material. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-71162 A Summary of the Invention [Problem to be solved by the invention]

[0006] Meanwhile, in the recycling process of solar cell modules, in addition to recovering valuable metals for the purpose of metal recycling, it is also required to separate and recover the protective member and the sealing material, which are made of different resin components, for the purpose of resin recycling. In this regard, the method of Patent Document 1 removes the sealing material and the protective member together by heat treatment, and does not take into consideration the separation and recovery and recycling of these.

[0007] Furthermore, the method of Patent Document 1 requires heat treatment, which not only makes the treatment process complicated, but also makes it difficult to continuously recycle solar cell modules from the standpoint of cost.

[0008] An object of the present invention is to provide a technique for recovering valuable metals from solar cell modules and for separating and recovering different resin components by type in a simple process. [Means for solving the problem]

[0009] The present inventors have investigated a treatment method that does not involve heat treatment, and have focused on crushing a solar cell sheet-like structure, which is an intermediate product of partially disassembling a solar cell module. The crushed material obtained by the crushing process includes powders derived from the solar cell and metal patterns, and resin powders derived from the sealing material and protective material. These powders have different weights, electrostatic charges, and electrical conductivity depending on the material from which they are derived. For this reason, it has been found that it is effective to perform wind sorting and electrostatic sorting on the crushed material in order to separate these powders into types of materials.

[0010] The following aspects have been created based on the above findings.

[0011] The first aspect of the present invention is a preparation step of removing a glass substrate and a frame member from a solar cell module and preparing a solar cell sheet-like structure including at least a solar cell, a metal pattern wired from the solar cell, a resin sealing material for sealing these, and a resin protective member provided on one side of the sealing material; a crushing step of crushing the solar cell sheet structure to form a crushed material containing powder derived from each component; A separation process in which the crushed material is subjected to electrostatic separation and air separation to separate the powder into metals and resins. A method for treating a solar cell module.

[0012] The second aspect of the present invention is the method according to the first aspect, In the separation process, the powder contained in the crushed material is separated into heavy materials and other resin light materials by air sorting, and then the light materials are separated by electrostatic sorting into low-insulation powder with a low volume resistivity and high-insulation powder with a relatively high volume resistivity.

[0013] A third aspect of the present invention is a preparation step of removing a glass substrate and a frame member from a solar cell module and preparing a solar cell sheet-like structure including at least a solar cell, a metal pattern wired from the solar cell, a resin sealing material for sealing these, and a resin protective member provided on one side of the sealing material; a crushing step of crushing the solar cell sheet structure to form a crushed material containing powder derived from each component; A separation process in which the crushed material is electrostatically separated into a conductive powder, a low insulating powder having a low volume resistivity, and a high insulating powder having a relatively high volume resistivity. A method for treating a solar cell module.

[0014] A fourth aspect of the present invention relates to a method for producing a composition according to the third aspect, After the separation step, the low insulation powder and the high insulation powder are each separated into heavy and light items by wind sorting.

[0015] A fifth aspect of the present invention is a method for producing a composition according to any one of the first, second, and fourth aspects, In the separation step, wind speed is set to 5 m / s or more and 20 m / s or less to perform wind separation.

[0016] A sixth aspect of the present invention is any one of the first to fifth aspects, The encapsulant includes ethylene-vinyl acetate resin, and the protective member includes polyethylene terephthalate.

[0017] A seventh aspect of the present invention is any one of the first to sixth aspects, In the separation step, electrostatic separation is performed by applying a voltage between the electrodes of 10 kV or more and 30 kV or less.

[0018] The eighth aspect of the present invention is any one of the first to seventh aspects, In the crushing step, the solar cell sheet structure is crushed so that the particle size of the crushed pieces is 20 mm or less. Effect of the Invention

[0019] According to the present invention, valuable metals can be recovered from solar cell modules, and different resin components can be separated and recovered by type in a continuous, simple process. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic cross-sectional view of a solar cell module. [Diagram 2] FIG. 2 is a schematic cross-sectional view of a solar cell sheet structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] <One embodiment of the present invention> A method for treating a solar cell module according to an embodiment of the present invention will be described below. The method for treating a solar cell module according to the present embodiment includes a preparation step, a crushing step, and a separation step. Each step will be described in detail below.

[0022] (preparation process) First, a solar cell sheet structure (hereinafter, simply referred to as a sheet structure) to be treated is prepared. The sheet structure is a solar cell module from which the glass substrate and frame member have been removed.

[0023] As shown in FIG. 1, the solar cell module 1 is configured to include a plurality of solar cells 11, a metal pattern 12 wired from the solar cells 11, a resin sealing material 13 that seals the solar cells 11 and the metal pattern 12, a resin protective member 14 provided on one side of the sealing material 13, a glass substrate 15 provided on the other side of the sealing material 13, and a frame member 16 that surrounds the laminate including the sealing material 13 and the glass substrate 15.

[0024] In the solar cell module 1, the solar cell 11 is formed of a semiconductor containing, for example, silicon. The metal pattern 12 is a metal member that is wired from the solar cell 11, and is configured to include, for example, a surface electrode provided on the surface of the solar cell 11 and a bus bar electrode that electrically connects the solar cell 11. The metal pattern 12 contains a valuable metal such as copper (Cu) or silver (Ag), the surface electrode is mainly formed of Ag, and the bus bar electrode is mainly formed of Cu. The sealing material 13 is formed of a resin such as ethylene-vinyl acetate copolymer (EVA) or polyethylene. The protective member 14 is formed of a resin different from the sealing material 13, for example, a resin such as polyethylene terephthalate (PET) or a fluororesin. The glass substrate 15 is formed of, for example, glass. The frame member 16 is formed of, for example, a metal or a resin.

[0025] 2, with the glass substrate 15 and frame member 16 removed from the solar cell module 1. Specifically, the sheet-like structure 10 includes solar cells 11, metal patterns 12 that are wired from the solar cells 11, a sealant 13 that seals the solar cells 11 and the metal patterns 12, and a protective member 14 provided on one side of the sealant 13.

[0026] The method for removing the glass substrate 15 and the frame member 16 from the solar cell module 1 is not particularly limited, and any known method can be used. For example, the hot knife method, roll crushing method, shot blasting method, etc. can be used to remove the glass substrate 15.

[0027] (Crushing process) Next, the sheet-like structure 10 is crushed. As a result, crushed material containing powders derived from each component is obtained. The powders contained in the crushed material include powders containing semiconductor materials derived from the solar cell 11, metal powders containing valuable metals derived from the metal pattern 12, resin powders derived from the sealing material 13, and resin powders derived from the protective member 14. In some cases, the contact points between the sealing material 13 and the protective member 14 are crushed, and powders in which the resin of the sealing material 13 and the resin of the protective member 14 are bonded to each other may be mixed in.

[0028] In crushing the sheet-like structure 10, the more soft and viscous the material, such as resin, the more roughly the members are crushed, while the more hard and brittle the material, such as metal or Si, the more finely they tend to be crushed. Specifically, the solar cell 11 containing silicon and the metal pattern 12 containing valuable metals are easily crushed. On the other hand, the sealing material 13 and the protective member 14 made of resin are soft and therefore roughly crushed. In other words, each member constituting the sheet-like structure 10 is crushed into powders with different particle sizes depending on the material. Such crushed material makes it easier to separate each powder based on the charge difference and specific gravity difference by electrostatic sorting or air sorting, which will be described later.

[0029] The size (particle size) of the crushed material is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 10 mm or less. By making the crushed material have such a size, it becomes easier to separate the powder by the difference in specific gravity or charge when performing the wind separation and electrostatic separation in the separation process described later. The size of the crushed material varies depending on the crushing method, but it is preferable to make it as small as possible while taking into consideration the processing cost.

[0030] As a crushing method, from the viewpoint of crushing each member constituting the sheet-like structure 10 to a size according to its material, shear crushing that can apply a shearing action to the sheet-like structure 10 is preferable. As the crusher to be used, a known crusher such as a uniaxial crusher or a biaxial crusher can be used, but a uniaxial crusher is preferable. In a biaxial crusher, depending on the crushing conditions, the crushed material is crushed uniformly and finely, and the particle size is likely to be uniform. On the other hand, in a uniaxial crusher, the crushing is rough, and the crushed material obtained is likely to have a non-uniform particle size and a wide particle size distribution. Therefore, the uniaxial crusher makes it easy to crush the solar cell 11, the metal pattern 12, the sealant 13, and the protective member 14 to a particle size according to their respective materials without crushing the sealant 13 and the protective member 14 made of resin too finely. This makes it easy to separate the crushed material into each member in the separation process described below.

[0031] As the uniaxial crusher, there are uniaxial cutter mills and uniaxial hammer mills depending on the shape of the blade, but from the viewpoint of shear crushing, the uniaxial cutter mill is preferred.

[0032] The crushing conditions are not particularly limited, and the number of blades in the crusher, the blade clearance, the blade rotation speed, etc. may be appropriately adjusted so that the particle size distribution of the crushed material becomes wide. The sheet-like structure may be crushed in one step, or may be gradually crushed in multiple steps such as primary crushing and secondary crushing.

[0033] (separation process) Next, the powder contained in the crushed material is separated into types of metal and resin. In this embodiment, the crushed material is subjected to air sorting and electrostatic sorting. In the following, an example will be described in which the crushed material is subjected to air sorting and then electrostatic sorting.

[0034] (Wind sorting) First, the crushed material is subjected to wind sorting. The crushed material contains powders of different weights, so by blowing wind onto the crushed material, it can be separated into heavy materials and lighter materials. Here, powders containing silicon and the like derived from the solar cell 11 and metal powders containing valuable metals derived from the metal pattern 12 are collected as heavy materials. Resin powders derived from the sealing material 13 and protective member 14 are collected as light materials.

[0035] In the wind sorting, the wind speed is not particularly limited, but from the viewpoint of separating the metal powder and the resin powder, it is preferable that the wind speed is 5 m / s or more and 20 m / s or less. By performing the wind sorting at such a wind speed, it is possible to more reliably separate the powder containing a large amount of valuable metals as a heavy material and the resin powder as a light material. The wind speed indicates the speed of the air hitting the powder.

[0036] The wind sorting machine to be used is not particularly limited, and known sorting machines such as circulation type, air knife type, blowing type, suction type, or closed type can be used. From the viewpoint of selectively and efficiently collecting heavy materials, circulation type, blowing type, and closed type are preferred. Dry or wet classification (process of sorting by specific gravity) using gravity, inertial force, centrifugal force, etc. can be used instead of wind sorting, but wind sorting is preferred from the viewpoint of processing capacity and cost.

[0037] (Electrostatic sorting) Next, the lightweight objects obtained by the wind sorting are subjected to electrostatic sorting using an electrostatic sorting device. In this embodiment, since the lightweight objects contain resin, the lightweight objects are charged by corona discharge, and then the lightweight objects are separated into different resin types based on the difference in the chargeability and conductivity of the resin contained in the lightweight objects.

[0038] As the electrostatic separation device, a conventionally known device can be used. For example, an electrostatic separation device can be used that includes a rotatably supported grounded metal drum electrode, a needle-shaped or blade-shaped high-voltage electrode provided opposite the grounded metal drum electrode, an electrostatic electrode provided opposite the grounded metal drum electrode downstream of the high-voltage electrode in the rotation direction of the grounded metal drum electrode, a brush for removing powder adhering to the grounded metal drum electrode, and a separation container for separately storing the separated powder.

[0039] In the electrostatic sorting device, a voltage is first applied between the grounded metal drum electrode and the high voltage electrode to generate a corona discharge. Then, the objects to be sorted (here, light objects) are fed onto the grounded metal drum electrode and transported. The objects are transported to the area under the high voltage electrode and charged with the same sign as the high voltage electrode. When the charged objects leave the area where the gas ions are applied as the grounded metal drum rotates, they release their charge to the grounded metal drum at a speed according to the conductivity of the objects. Conductive objects quickly release their charge, become electrically neutral, and drop off the grounded metal drum electrode. If the object has high conductivity, it is charged with the opposite sign to that of the grounded metal drum, and jumps from the grounded metal drum in the direction of rotation of the grounded metal drum due to repulsion between the same signs as the grounded metal drum, and falls while being attracted to the high voltage electrostatic electrode installed in the jumping direction. On the other hand, non-conductive objects are less likely to release their charge to the grounded metal drum, and are attracted to the opposite sign of the grounded metal drum, and rotate together with the grounded metal drum while adhering to the grounded metal drum. Objects rotated with the grounded metal drum are physically removed by brushes attached to the grounded metal drum.

[0040] Specifically, the lightweight materials mainly include resin powder originating from the sealing material 13 and resin powder originating from the protective member 14. The resin powder originating from the sealing material 13 and the resin powder originating from the protective member 14 are composed of different resins, and therefore have different volume resistivities, and differ in ease of charging and conductivity. Therefore, by electrostatically separating the lightweight materials, the resin powder originating from the sealing material 13 and the resin powder originating from the protective member 14 can be separated into low-insulating powder with a small volume resistivity and high-insulating powder with a relatively large volume resistivity due to the difference in charging property and the difference in conductivity. In other words, the lightweight materials can be separated according to the type of resin of the sealing material 13 or the protective member 14. Note that the powder in which the resin of the sealing material 13 and the resin of the protective member 14 are bonded is classified into both low-insulating powder and high-insulating powder. Alternatively, the powder may be separated and collected separately as a powder having intermediate properties between the low-insulating powder and the high-insulating powder.

[0041] The low insulation powder and high insulation powder vary depending on the type of resin that forms the sealing material 13 and the protective member 14. For example, when the sealing material 13 is made of EVA and the protective member 14 is made of PET, since PET is more easily charged and has lower conductivity (high insulation) than EVA, the powder originating from the protective member 14 is separated as high insulation powder and the powder originating from the sealing material 13 is separated as low insulation powder.

[0042] Resin powder that can be electrostatically separated has a volume resistivity of 1.0×10 8 [Ω cm] or more 1.0×10 19 From the viewpoint of efficient electrostatic separation of low-insulation powder and high-insulation powder, the volume resistivity of the high-insulation powder is set to be 1.0 × 10 3 It is preferable that the volume resistivity of the powder is 1.5×10 or more. The greater the difference in the volume resistivity of these powders, the more efficient the electrostatic separation. The volume resistivities of the resins used in the sealing material 13 and the protective member 14 are as follows: EVA is 1.5×10 8 [Ω·cm], and polyethylene resin is 1.0×10 16 [Ω cm], PET is 1.0×10 19 [Ω·cm], and fluororesin is 2.0×10 14[Ω cm].

[0043] The voltage applied during electrostatic sorting is not particularly limited, and may be appropriately set so that the resin powder derived from the sealing material 13 and the resin powder derived from the protective member 14 can be separated into high insulation powder and low insulation powder due to the difference in chargeability or conductivity (difference in volume resistivity). From the viewpoint of generating sufficient corona discharge between the electrodes and applying sufficient charge to the object to be sorted, it is preferable that the voltage applied between the electrodes is 5 kV or more. On the other hand, if the applied voltage is excessively high, sparks may occur and both the high insulation powder and the low insulation powder will adhere to the grounded metal drum, which is not preferable from the viewpoint of sorting efficiency. However, the allowable range of the maximum applied voltage varies depending on the distance between the grounded metal drum and the high voltage electrode or the change in the properties or shape of the object to be sorted. To sort the powder derived from the resin constituting the sealing material 13 or the protective member 14, it is more preferable that the applied voltage is 10 kV or more and 30 kV or less.

[0044] The distance and installation angle of the needle-shaped or blade-shaped high-voltage electrode and the high-voltage electrostatic electrode from the grounded metal drum electrode, and the rotation speed of the grounded metal drum electrode are not particularly limited and can be changed as appropriate. For example, the rotation speed of the grounded metal drum electrode can be adjusted to 10 rpm to 60 rpm, the distance between the needle-shaped or blade-shaped high-voltage electrode and the grounded metal drum electrode can be adjusted to 0.5 cm to 5 cm, the distance between the high-voltage electrostatic electrode and the grounded metal drum can be adjusted to 3 cm to 20 cm, and the installation angle of the needle-shaped or blade-shaped high-voltage electrode and the high-voltage electrostatic electrode can be adjusted within a range of +90 degrees to -90 degrees with the horizontal direction of the grounded metal drum as the axis reference. In addition, when carrying out this electrostatic sorting with the voltage applied to the electrode being 10 kV or more and 30 kV or less, the rotation speed of the rotating drum electrode is 10 rpm to 30 rpm, the distance between the needle-shaped or blade-shaped high-voltage electrode and the grounded metal drum electrode is 1 cm to 2 cm, the distance between the high-voltage electrostatic electrode and the grounded metal drum is 5 cm to 10 cm, the installation angle of the needle-shaped or blade-shaped high-voltage electrode is +40 degrees to +50 degrees with the horizontal direction of the grounded metal drum as the reference axis, and the installation angle of the high-voltage electrostatic electrode is 0 degrees to +30 degrees with the horizontal direction of the grounded metal drum as the reference axis. Note that when the voltage applied to the electrode is changed, each optimal condition is also changed.

[0045] In addition, the electrostatic separation may be performed not only once, but multiple times. For example, the low insulation powder and the high insulation powder obtained by the electrostatic separation may be electrostatically separated separately. In performing the electrostatic separation multiple times, multiple separation containers are used that are installed at the bottom of the electrostatic separation device. By using a separation container that collects the powder that jumps from the grounded metal drum electrode and falls while being attracted to the high voltage electrostatic electrode, a separation container that collects the powder that detaches from the grounded metal drum electrode and falls, and a separation container that collects the powder that remains attached to the grounded metal drum electrode and rotates together with the grounded metal drum, and is physically removed by a brush attached to the grounded metal drum and falls, it is possible to separate and collect the powder after electrostatic separation. In addition, a separation container is installed between the separation container that collects the powder that detaches from the grounded metal drum electrode and falls and the separation container that collects the powder that is physically removed by the brush attached to the grounded metal drum and falls, making it possible to collect powder in which the resin of the sealing material 13 and the resin of the protective material 14 are bonded together, and which is classified into both easily charged, non-conductive powder and difficult to charge, and conductive powder.

[0046] As a result, valuable metals contained in the solar cell module 1, the resin forming the sealing material 13, and the resin forming the protective member 14 can be separated by type and recovered.

[0047] <Effects of this embodiment> According to this embodiment, one or more of the following advantages are achieved.

[0048] In this embodiment, the sheet-like structure 10 from which the glass substrate 15 and the frame member 16 have been removed is crushed, and the crushed material is subjected to wind sorting and electrostatic sorting. First, by treating the sheet-like structure 10 as the processing target, components derived from the glass substrate 15 and the frame member 16 are separated. Next, by wind sorting the crushed material, silicon derived from the solar cell 11 and valuable metals derived from the metal pattern 12 can be recovered as heavy materials. In addition, by electrostatically sorting the light materials obtained by wind sorting, at least the resin powder derived from the sealing material 13 and the resin powder derived from the protective member 14 can be separated into low-insulation powder and high-insulation powder due to the difference in electrostatic charge and the difference in conductivity. Thus, according to the processing method of this embodiment, valuable metals can be recovered from the solar cell module 1, and the sealing material 13 and the protective member 14 can be separately recovered.

[0049] Furthermore, according to the processing method of this embodiment, valuable metals and resins can be mechanically separated by crushing the sheet-like structures 10 and subjecting the crushed pieces to wind sorting or electrostatic sorting. Therefore, the process can be simplified compared to processing methods that use heat treatment or chemical processing. Moreover, since crushing, wind sorting, and electrostatic sorting can be performed continuously, a large amount of sheet-like structures 10 can be processed continuously and efficiently.

[0050] In addition, the voltage applied in electrostatic separation is preferably 10 kV or more and 30 kV or less. Within this voltage range, it is possible to suppress the generation of sparks due to excessive applied voltage while generating corona discharge. Moreover, when electrostatically separating lightweight materials, it is possible to suitably separate low-insulation powder and high-insulation powder. Furthermore, with such an applied voltage, it is possible to more reliably separate the resin powder containing EVA as the low-insulation powder and the resin powder containing PET as the high-insulation powder.

[0051] In addition, it is preferable to set the wind speed of the wind blown on the crushed materials in the wind sorting to 5 m / s or more and 20 m / s or less. By setting the wind speed in this range, heavy materials containing valuable metals can be more reliably separated from light materials containing resins derived from the sealing material 13 and the protective member 14.

[0052] Moreover, it is preferable to crush the sheet-like structure 10 so that the particle size of the crushed material is 20 mm or less. By crushing the material into such particle sizes, the material can be more reliably separated during air sorting or electrostatic sorting based on the difference in specific gravity, chargeability, and conductivity of the powder.

[0053] <Other embodiments> Although the embodiment of the present invention has been specifically described above, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the gist of the present invention.

[0054] In the above embodiment, the solar cell sheet structure 10 includes the sealing material 13 and the protective member 14, and contains two types of resin. However, the solar cell sheet structure 10 may include other resin members. For example, the protective member 14 may be made of not a single resin but two or more resin layers laminated together, and three or more types of resin powder may be mixed in the crushed material. In such a case, the electrostatic separation conditions, such as the applied voltage, may be appropriately changed to perform electrostatic separation two or more times in order to separate the three or more types of resin contained in the crushed material.

[0055] In the above embodiment, the separation process is performed by first performing air separation and then performing electrostatic separation, but the present invention is not limited to this. For example, the crushed material may be subjected to electrostatic separation as it is. Preferably, each of the powder particles separated by electrostatic separation may be subjected to air separation. This point will be specifically described below.

[0056] As described above, the crushed material contains a mixture of powders originating from the solar cell 11, the metal pattern 12, the sealing material 13, and the protective member 14. The crushed material is subjected to electrostatic separation by setting the voltage between the electrodes so that at least the resin powder originating from the sealing material 13 and the resin powder originating from the protective member 14 can be separated. As a result, first, the powder group originating from the solar cell 11 and the metal pattern 12, which has particularly high conductivity, jumps from the grounded metal drum electrode, falls while being attracted to the electrostatic electrode, and is separated. Next, of the powder group containing the resin powder originating from the sealing material 13 and the powder group containing the resin powder originating from the protective member 14, those with relatively high conductivity and low insulation are separated as low-insulation powder. Finally, the highly insulating material is separated as the highly insulating powder. Specifically, if the sealing material 13 is made of EVA and the protective member 14 is made of PET, the metal powder is separated first, then the resin powder originating from the sealing material 13 is separated as the low insulating powder, and finally, the resin powder originating from the protective member 14 is separated as the high insulating powder. In this way, the conductive powder, the low insulating powder, and the high insulating powder can be separated by electrostatically separating the crushed material as it is.

[0057] Next, it is preferable to perform wind sorting on each of the low insulation powder and the high insulation powder separated by electrostatic sorting. Although the powder originating from the solar cell 11 and the metal pattern 12 is separated by the above-mentioned electrostatic sorting, it may be mixed into the low insulation powder or the high insulation powder. By performing wind sorting on each of the low insulation powder and the high insulation powder, it is possible to separate the powder originating from the metal pattern 12 as a heavy material and the powder made of resin as a light material. As described above, as in the above-mentioned embodiment, it is possible to separate and recover the sealing material 13 and the protective member 14 while recovering valuable metals. EXAMPLES

[0058] Next, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[0059] Example 1 The target for processing was a solar cell sheet-like structure (PV sheet) prepared by removing the glass substrate and frame member from a solar cell module. In the PV sheet, the encapsulant was made of EVA resin, and the protective member was made of PET. Next, the PV sheet was crushed using a nugget machine. Crushing was continued until the crushed material passed through a 3 mm screen, and if it did not pass through, the process was repeated. The nugget machine used was a single-axis cutter mill, "SKC-25-540L." The crushing conditions were adjusted to 45 blades, a clearance of about 2 mm, and a blade rotation speed of 630 rpm. The wind sorting machine used was "APS-250RB."

[0060] Next, the PV sheet crushed material with a particle size of 3 mm or less was subjected to wind sorting at a wind speed of 20 m / s. This separated the material into heavy and light items. The heavy items mainly contained valuable metals and powders derived from solar cells. The light items contained EVA powder (black) derived from the encapsulant and PET powder (white) derived from the protective materials.

[0061] Next, electrostatic separation was performed on the lightweight material containing the resin powder. Specifically, electrostatic separation was performed using an electrostatic separation device under the conditions of an applied voltage of 19 kV and a drum rotation speed of 20 rpm. First, the EVA powder, which is a powder that is difficult to charge and conductive, i.e., a low-insulation powder, was detached from the grounded metal drum electrode and dropped, and was separated and collected in a separation container installed below the grounded metal drum electrode. Next, the PET powder, which is a powder that is easily charged and non-conductive, i.e., a high-insulation powder, was rotated together with the grounded metal drum while remaining attached to the grounded metal drum, physically removed by a brush attached to the grounded metal drum, and separated and collected in a separation container installed below the brush. In addition, electrostatic separation was performed on the powders collected in each separation container three times, and the low-insulation powder and the high-insulation powder were collected, respectively.

[0062] In this embodiment, in order to confirm that the resins can be separated by type, the following evaluation was performed. Specifically, the ratio of EVA powder, which is a low insulating powder, to PET powder, which is a high insulating powder, was calculated for each of the following samples: the lightweight object before electrostatic separation, the dropped sample that dropped from the grounded metal drum electrode when the lightweight object was electrostatically separated, and the attached sample that was collected by a brush while still attached to the grounded metal drum electrode. This ratio was calculated by performing image analysis on each sample, regarding the white PET powder as the white region and the black EVA powder as the black region, and then calculating the ratio of the areas of each region.

[0063] As a result, it was confirmed that the lightweight materials before electrostatic separation contained 6% PET powder and 94% EVA powder per unit area. The fallen sample contained 1% PET powder and 99% EVA powder per unit area. The attached sample contained 8% PET powder and 92% EVA powder per unit area. The ratio of PET powder in the fallen sample was low at 1%, while the ratio in the attached sample was high at 8%. Furthermore, the ratio in the attached sample was higher than the ratio in the lightweight materials before electrostatic separation (6%), concentrating the PET powder. This confirmed that the PET powder could be efficiently separated as a highly insulating powder. [Explanation of symbols]

[0064] 1. Solar cell module 10. Solar cell sheet structure 11 Solar Cell 12 Metal Pattern 13 Encapsulating materials 14 Protective materials 15 Glass substrate 16 Frame members

Claims

1. a preparation step of removing a glass substrate and a frame member from a solar cell module and preparing a solar cell sheet-like structure including at least a solar cell, a metal pattern wired from the solar cell, a resin sealing material for sealing these, and a resin protective member provided on one side of the sealing material; a crushing process in which the solar cell sheet structure is shear-crushed to crush each component into a size according to its material, and crushed material containing a powder including a semiconductor material derived from the solar cell, a metal powder derived from the metal pattern, a resin powder derived from the sealing material, and a resin powder derived from the protective member is formed as powder derived from each component; A method for processing a solar cell module, comprising a separation process in which the crushed material, each of which has a size according to its material, is subjected to electrostatic sorting using corona discharge to separate the crushed material into conductive powder, low insulating powder having a low volume resistivity, and high insulating powder having a relatively high volume resistivity.

2. 2. The method for treating a solar cell module according to claim 1, further comprising the steps of: separating the low-insulating powder and the high-insulating powder into heavy and light powders by wind sorting.

3. The method for treating a solar cell module according to claim 2 , wherein in the separating step, wind sorting is performed at a wind speed of 5 m / s or more and 20 m / s or less.

4. The method for treating a solar cell module according to any one of claims 1 to 3, wherein the sealing material contains ethylene-vinyl acetate resin, and the protective member contains polyethylene terephthalate.

5. 5. The method for treating a solar cell module according to claim 1, wherein in the separation step, electrostatic separation is performed by applying a voltage between electrodes of 10 kV or more and 30 kV or less.

6. 6. The method for treating a solar cell module according to claim 1, wherein in the crushing step, the solar cell sheet structure is crushed so that the particle size of the crushed pieces is 20 mm or less.

Images