JP7253661B2 - Processing method of solar cell module - Google Patents

Description

The present invention relates to a method for processing a solar cell module.

Solar cell power generation uses the clean energy of sunlight and has a small environmental load, so it is attracting attention as a renewable energy. The solar cell module used for this solar cell power generation includes, for example, a glass substrate, a sealing material for sealing the solar cells, a protective member (so-called back sheet), and a metal pattern wired from the solar cells. and a frame member provided around the encapsulant.

In the past, solar cell modules were disposed of after being used for a certain period of time, but in recent years, it is required to recover valuable metals from the viewpoint of recycling. Valuable metals include copper and silver contained in the metal pattern.

Therefore, for example, Patent Document 1 is disclosed as a method for recovering valuable metals from solar cell modules. Patent Literature 1 proposes a method of heating a solar cell module to remove a sealing material and a protective member, and then recovering the solar cells.

JP 2015-71162 A

By the way, in the recycling of solar cell modules, in addition to recovering valuable metals for the purpose of metal recycling, it is also possible to separate and recover protective members and encapsulants formed from different resin components for the purpose of resin recycling. It has been demanded. In this regard, in the method of Patent Document 1, since the sealing material and the protective member are removed together by heat treatment, no consideration is given to collecting and recycling them separately.

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

An object of the present invention is to provide a technique for recovering valuable metals from a solar cell module and separating and recovering different resin components by type in a simple process.

The present inventors have studied a processing method that does not involve heat treatment, etc., and focused on crushing a solar cell sheet-like structure, which is an intermediate product obtained by partially disassembling a solar cell module, as a processing target. The crushed material obtained by the crushing treatment includes powder derived from the solar cells and the metal pattern, resin powder derived from the sealing material and the protective member, and the like. These powders differ in weight, susceptibility to electrification, and conductivity depending on the member from which they are derived. From this, the inventors have found that it is effective to subject the crushed material to air sorting and electrostatic sorting in order to separate these powders according to the types of members.

The following aspects were created based on the above findings.

A first aspect of the present invention is
The glass substrate and the frame member are removed from the solar cell module, and at least the solar cell, the metal pattern wired from the solar cell, the resin sealing material for sealing these, and the sealing material. A preparation step of preparing a solar cell sheet-like structure comprising a resin protective member provided on one surface;
A crushing step of crushing the solar cell sheet-like structure to form a crushed material containing powder derived from each member;
a separation step of subjecting the crushed material to electrostatic sorting and wind sorting, and separating the powder by type of metal and resin;
A processing method for a solar cell module.

A second aspect of the present invention is, in the first aspect,
In the separation step, after the powder contained in the crushed material is separated into heavy materials and other lightweight materials of resin by wind separation, the light materials are electrostatically sorted to obtain low volume resistivity. It separates into insulating powder and highly insulating powder having a relatively high volume resistivity.

A third aspect of the present invention is
The glass substrate and the frame member are removed from the solar cell module, and at least the solar cell, the metal pattern wired from the solar cell, the resin sealing material for sealing these, and the sealing material. A preparation step of preparing a solar cell sheet-like structure comprising a resin protective member provided on one surface;
A crushing step of crushing the solar cell sheet-like structure to form a crushed material containing powder derived from each member;
A separation step of electrostatically sorting the crushed material into conductive powder, low-insulating powder with low volume resistivity, and high-insulating powder with relatively high volume resistivity,
A processing method for a solar cell module.

A fourth aspect of the present invention is, in the third aspect,
After the separation step, each of the low-insulation powder and the high-insulation powder is separated into heavy weights and light weights by wind sorting.

A fifth aspect of the present invention is any one of the first, second, and fourth aspects,
In the separation step, wind separation is performed at a wind speed of 5 m/s or more and 20 m/s or less.

A sixth aspect of the present invention is any one of the first to fifth aspects,
The sealing material contains ethylene-vinyl acetate resin, and the protective member contains polyethylene terephthalate.

A seventh aspect of the present invention is any one of the first to sixth aspects,
In the separation step, electrostatic selection is performed with a voltage of 10 kV or more and 30 kV or less applied to the electrodes.

An eighth aspect of the present invention is any one of the first to seventh aspects,
In the crushing step, the solar cell sheet-like structure is crushed so that the particle size of the crushed material is 20 mm or less.

Advantageous Effects of Invention According to the present invention, it is possible to collect valuable metals from a solar cell module and separate and collect different resin components by type continuously in a simple process.

FIG. 1 is a schematic cross-sectional view of a solar cell module. FIG. 2 is a schematic cross-sectional view of a solar cell sheet-like structure.

<One embodiment of the present invention>
Hereinafter, a method for processing a solar cell module according to an embodiment of the present invention will be described. The processing method of this embodiment has a preparation step, a crushing step and a separation step. Each step will be described in detail below.

(Preparation process)
First, a solar cell sheet-like structure (hereinafter also simply referred to as a sheet-like structure) to be processed is prepared. The sheet-like structure is obtained by removing the glass substrate and the frame member from the solar cell module.

For example, as shown in FIG. 1, the solar battery module 1 includes a plurality of solar battery cells 11, a metal pattern 12 wired from the solar battery cells 11, and a resin material sealing the solar battery cells 11 and the metal pattern 12. A sealing material 13, a resin protective member 14 provided on one surface of the sealing material 13, a glass substrate 15 provided on the other surface of the sealing material 13, the sealing material 13, the glass substrate 15, and the like. and a frame member 16 surrounding the laminate.

In the solar cell module 1, the solar cells 11 are made of a semiconductor containing silicon, for example. The metal pattern 12 is a metal member that is wired from the solar cell 11 , and includes, for example, a surface electrode provided on the surface of the solar cell 11 and a bus bar electrode that electrically connects between the solar cells 11 . be done. The metal pattern 12 contains a valuable metal such as copper (Cu) or silver (Ag), the surface electrodes are mainly made of Ag, and the busbar electrodes are mainly made of Cu. The sealing material 13 is made of resin such as ethylene-vinyl acetate copolymer (EVA) or polyethylene. The protective member 14 is made of a resin different from that of the sealing material 13, such as polyethylene terephthalate (PET) or fluorine resin. The glass substrate 15 is made of glass, for example. The frame member 16 is made of metal, resin, or the like, for example.

The sheet-like structure 10 is configured as shown in FIG. 2 by removing the glass substrate 15 and the frame member 16 from the solar cell module 1 . Specifically, the solar battery cell 11, the metal pattern 12 wired from the solar battery cell 11, the sealing material 13 that seals the solar battery cell 11 and the metal pattern 12, and one of the sealing materials 13 and a protection member 14 provided on the surface.

A method for removing the glass substrate 15 and the frame member 16 from the solar cell module 1 is not particularly limited, and a known method can be adopted. For removing the glass substrate 15, for example, a hot knife method, a roll crushing method, a shot blasting method, or the like can be used.

(Crushing process)
Subsequently, the sheet-like structure 10 is crushed. As a result, a crushed material containing powder derived from each member is obtained. The powders contained in the crushed material include powders containing semiconductor materials derived from the solar cells 11, metal powders containing valuable metals derived from the metal patterns 12, resin powders derived from the sealing material 13, protective There are resin powder derived from the member 14 and the like. In some cases, the portion where the sealing material 13 and the protective member 14 are in contact with each other may be crushed, and the resin of the sealing material 13 and the resin of the protective member 14 may be mixed together in the form of powder.

In the crushing of the sheet-like structure 10, for example, members made of a soft and sticky material such as resin are crushed coarsely, and members made of a hard and brittle material such as metal or Si are finely crushed. tend to be crushed. Specifically, solar cells 11 containing silicon and metal patterns 12 containing valuable metals are easily crushed into small pieces. On the other hand, the sealing material 13, the protective member 14, and the like made of resin are roughly crushed because they are soft. That is, each member constituting the sheet-like structure 10 is crushed into powders having different particle diameters depending on the material. According to such a crushed material, each powder can be easily sorted by electrostatic sorting or wind sorting, which will be described later, based on differences in electrification and specific gravities.

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 setting the crushed material to such a size, the powder can be easily sorted by the specific gravity difference and the charge difference when wind sorting and electrostatic sorting are performed in the later-described separation step. Although the size of the crushed material varies depending on the crushing method, it is preferable to make it as small as possible in consideration of the processing cost.

From the viewpoint of crushing each member constituting the sheet-like structure 10 so as to have a size corresponding to the material thereof, shear crushing capable of imparting a shearing action to the sheet-like structure 10 is preferable as the crushing method. . As the crusher to be used, for example, a known crusher such as a uniaxial crusher or a biaxial crusher can be used, but a uniaxial crusher is preferable. Depending on the crushing conditions, the twin-screw crusher may uniformly crush the crushed material finely, and the particle size tends to be uniform. On the other hand, with a uniaxial crusher, crushing is rough, and the grain size of the resulting crushed product is non-uniform, and the grain size distribution is wide. Therefore, according to the uniaxial crusher, the solar cell 11, the metal pattern 12, the sealing material 13 and the protective member 14 can be separated from each other without excessively finely crushing the sealing material 13 and the protective member 14 made of resin. It is easy to crush to a particle size according to the material. As a result, the crushed material can be easily sorted for each member in the later-described separation step.

The uniaxial crusher includes a uniaxial cutter mill, a uniaxial hammer mill, and the like depending on the shape of the blade, but the uniaxial cutter mill is preferable from the viewpoint of shearing and crushing.

The crushing conditions are not particularly limited, and the number of blades in the crusher, the clearance between the blades, the number of rotations of the blades, etc. may be appropriately adjusted so that the particle size distribution of the crushed material is widened. Moreover, the sheet-like structure may be crushed in one step, or may be crushed gradually in multiple steps such as primary crushing and secondary crushing.

(Separation process)
Subsequently, the powder contained in the crushed material is separated according to the types of metals and resins. In this embodiment, the pulverized material is subjected to wind sorting and electrostatic sorting. In the following, an example will be described in which the electrostatic sorting is performed after the pulverized material is sorted by wind force.

(Wind sorting)
First, the crushed material is subjected to wind sorting. Since the crushed material contains powders of different weights, it is possible to separate the heavy material from the lighter material by blowing air onto the crushed material. Here, as the heavy object, powder containing silicon derived from the solar cell 11 and metal powder containing valuable metal derived from the metal pattern 12 are collected. Resin powder originating from the sealing material 13 and the protective member 14 is collected as the lightweight material.

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 preferably 5 m/s or more and 20 m/s or less. By performing wind separation at such a wind speed, it is possible to more reliably separate powders containing a large amount of valuable metals as heavy weights and resin powders as light weights. Note that the wind speed indicates the speed of the air hitting the powder.

The wind sorter to be used is not particularly limited, and known sorters such as a circulation type, an air knife type, a blow-up type, a suction type, and a closed type can be used. From the viewpoint of selectively and efficiently collecting heavy objects, the circulation type, the blowing-up type and the closed type are preferable. Dry or wet classification (processing for sorting by specific gravity) using gravity, inertial force, centrifugal force, etc. can be used instead of air separation, but air separation is preferable from the viewpoint of processing capacity and cost.

(electrostatic sorting)
Next, the lightweight material obtained by the wind sorting is subjected to electrostatic sorting using an electrostatic sorter. In this embodiment, since the lightweight objects contain resin, after the lightweight objects are charged by corona discharge, the lightweight objects are sorted according to the type of resin based on the difference in chargeability and conductivity of the resin contained in the lightweight objects. .

A conventionally known device can be used as the electrostatic sorting device. For example, a ground metal drum electrode rotatably supported, a needle-like or blade-like high voltage electrode provided facing the ground metal drum electrode, and a high voltage electrode downstream of the high voltage electrode in the rotation direction of the ground metal drum electrode. an electrostatic sorting device comprising: an electrostatic electrode provided facing a grounded metal drum electrode; a brush for removing powder adhering to the grounded metal drum electrode; and a separation container for separately storing the sorted powder. can be used.

In an electrostatic sorting apparatus, first, a voltage is applied between a grounded metal drum electrode and a high voltage electrode to generate corona discharge. Subsequently, an object to be sorted (here, a lightweight object) is fed onto the grounded metal drum electrode and conveyed. An object is transported to the area under the high voltage electrode and charged to the same sign as the high voltage electrode. The charged object releases charge to the grounded metal drum at a rate that depends on the conductivity of the object as the grounded metal drum rotates away from the gas ion application area. A conductive object quickly releases its charge, becomes electrically neutral, detaches from the grounded metal drum electrode, and falls. When the object has high conductivity, the object is charged with the opposite sign of the grounded metal drum, and jumps from the grounded metal drum in the rotation direction of the grounded metal drum due to repulsion between the same signs as the grounded metal drum. It falls while being attracted by a high-voltage electrostatic electrode installed in the direction. On the other hand, a non-conductive object is less likely to release charge to the grounded metal drum, is attracted to the opposite sign of the grounded metal drum, and rotates with the grounded metal drum while remaining adhered to the grounded metal drum. Objects rotated with the grounded metal drum are physically removed by brushes attached to the grounded metal drum.

Specifically, the lightweight material mainly includes resin powder derived from the sealing material 13 and resin powder derived from the protective member 14 . Since the resin powder derived from the sealing material 13 and the resin powder derived from the protective member 14 are made of different resins, they have different volume resistivities, different easiness of electrification, and different conductivity. Therefore, by electrostatically sorting the lightweight materials, the resin powder derived from the sealing material 13 and the resin powder derived from the protective member 14 can be distinguished from each other by the difference in the chargeability and the conductivity. It can be separated into small low-insulating powder and high-insulating powder with relatively high volume resistivity. In other words, lightweight objects can be separated according to the type of resin of the sealing material 13 and the protective member 14 . The powder obtained by bonding the resin of the sealing material 13 and the resin of the protective member 14 is classified into both low-insulation powder and high-insulation powder. Alternatively, a powder having properties intermediate between those of the low-insulation powder and the high-insulation powder may be separated and collected separately from these.

Low-insulating powder and high-insulating powder vary depending on the type of resin forming sealing material 13 and protective member 14 . For example, when the sealing material 13 is made of EVA and the protective member 14 is made of PET, the powder derived from the protective member 14 is highly insulating powder because PET is more easily charged and has lower conductivity (higher insulation) than EVA. As a result, the powder derived from the sealing material 13 is separated as low-insulation powder.

The resin powder that can be electrostatically separated has a volume resistivity of 1.0×10 ⁸ [Ω·cm] or more and 1.0×10 ¹⁹ [Ω·cm] or less. From the viewpoint of efficient electrostatic separation of low-insulation powder and high-insulation powder, the volume resistivity of the high-insulation powder is preferably 1.0×10 ³ times or more that of the low-insulation powder. . This is because the more the volume resistivities of these powders deviate, the more efficiently the electrostatic separation can be performed. In addition, the volume resistivity of the resin used for the sealing material 13 and the protective member 14 is as follows. EVA is 1.5×10 ⁸ [Ω・cm], polyethylene resin is 1.0×10 ¹⁶ [Ω・cm], PET is 1.0×10 ¹⁹ [Ω・cm], fluororesin is 2.0× 10 ¹⁴ [Ω·cm].

The voltage applied during electrostatic sorting is such that the resin powder derived from the sealing material 13 and the resin powder derived from the protective member 14 are highly insulated due to the difference in chargeability and conductivity (difference in volume resistivity). There is no particular limitation as long as it is appropriately set so that the powder and the low-insulation powder can be separated. The voltage applied between the electrodes is preferably 5 kV or more from the viewpoint of sufficiently generating corona discharge between the electrodes and sufficiently applying electric charges to the objects to be sorted. 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 adhere to the grounded metal drum. The permissible range of the maximum value of the applied voltage fluctuates due to the extension of the distance between the high-voltage electrode and the change in the properties and shapes of the objects to be sorted. In order to sort out the powder derived from the resin forming the sealing material 13 and the protective member 14, the applied voltage is more preferably 10 kV or more and 30 kV or less.

The distance and installation angle of the needle-like or blade-like 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 ground metal drum electrode is 10 rpm to 60 rpm, the distance between the needle-like or blade-like high voltage electrode and the ground metal drum electrode is 0.5 cm to 5 cm, and the distance between the high voltage electrostatic electrode and the ground metal drum. is 3 cm to 20 cm, and the installation angle of the needle-like or blade-like high voltage electrode and the high voltage electrostatic electrode can be adjusted in the range of +90° to -90° with the horizontal direction of the grounded metal drum as the reference of the axis. In addition, in the implementation of this electrostatic sorting in which the voltage applied to the electrode is 10 kV or more and 30 kV or less, the rotation speed of the rotating drum electrode is 10 rpm to 30 rpm, and the needle-like or blade-like high voltage electrode and the ground metal drum electrode The distance 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, and the installation angle of the needle-like or blade-like high voltage electrode is +40 degrees or more with the horizontal direction of the grounded metal drum as the reference. +50 degrees, and the installation angle of the high-voltage electrostatic electrode should be adjusted in the range of 0 degrees to +30 degrees with the horizontal direction of the grounded metal drum as the reference of the axis. When the voltage applied to the electrodes is changed, each optimum condition is also changed.

In addition, the electrostatic sorting operation may be performed not only once but also multiple times. For example, each of low-insulation powder and high-insulation powder obtained by electrostatic screening may be electrostatically screened. When carrying out multiple times, multiple separation vessels installed at the bottom of the electrostatic sorting device are used. A separation container that collects powder that jumps from a grounded metal drum electrode and falls while being attracted by a high-voltage electrostatic electrode, a separation container that collects powder that detaches and falls from the grounded metal drum electrode, and a grounded metal drum electrode. The powder after electrostatic sorting is separated by using a separation container that rotates with the grounded metal drum while remaining attached and collects the falling powder that is physically removed by a brush attached to the grounded metal drum. It is possible to collect In addition, there is also a separation container between the separation container for collecting the powder that detaches and falls from the grounded metal drum electrode and the separation container for collecting the powder that is physically removed and dropped by the brush attached to the grounded metal drum. is installed, and the resin of the sealing material 13 and the resin of the protective member 14 are adhered to each other. can be recovered.

As described above, the valuable metals contained in the solar cell module 1, the resin forming the encapsulant 13, and the resin forming the protective member 14 can be sorted by type and collected.

<Effects of this embodiment>
According to this embodiment, one or more of the following effects can be obtained.

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 air separation and electrostatic separation. First, by using the sheet-like structure 10 as the object to be processed, the components derived from the glass substrate 15 and the frame member 16 are separated. Subsequently, by sorting the crushed material by wind power, silicon derived from the solar cell 11 and valuable metal derived from the metal pattern 12 can be recovered as heavy materials. In addition, by electrostatically sorting the lightweight materials obtained by the wind sorting, at least the resin powder derived from the sealing material 13 and the resin powder derived from the protective member 14 are separated from each other in chargeability and conductivity. can be separated into low-insulation powder and high-insulation powder. As described above, according to the processing method of the present embodiment, the valuable metal can be recovered from the solar cell module 1, and the encapsulant 13 and the protective member 14 can be separated and recovered.

Further, according to the processing method of the present embodiment, the sheet-like structure 10 is crushed and the crushed material is sorted by wind or electrostatic separation, thereby mechanically separating the valuable metal and the resin. Therefore, the process can be simplified compared to treatment methods using heat treatment or chemical treatment. Moreover, since the crushing, the wind separation, and the electrostatic separation can be performed continuously, a large amount of the sheet-like structure 10 can be processed continuously and efficiently.

Moreover, the voltage applied in the electrostatic sorting is preferably 10 kV or more and 30 kV or less. Within this voltage range, it is possible to suppress generation of sparks due to excessive applied voltage while generating corona discharge. Moreover, when the lightweight objects are electrostatically sorted, the low-insulation powder and the high-insulation powder can be preferably separated. Further, with such an applied voltage, resin powder containing EVA can be separated as low-insulating powder, and resin powder containing PET can be more reliably separated as high-insulating powder.

Moreover, it is preferable that the wind speed of the wind blowing on the crushed objects in the wind sorting is 5 m/s or more and 20 m/s or less. With such a wind speed, heavy objects containing valuable metals and light objects containing resin derived from the sealing material 13 and the protective member 14 can be more reliably separated.

Moreover, the sheet-like structure 10 is preferably crushed so that the particle size of the crushed material is 20 mm or less. By using such a particle size, it is possible to more reliably separate powders by the difference in specific gravity, chargeability and conductivity during air separation or electrostatic separation.

<Other embodiments>
Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

In the above-described embodiment, the solar cell sheet-like structure 10 includes the encapsulant 13 and the protective member 14, and includes two types of resin. However, other resin members may be included. For example, the protective member 14 may be constructed by laminating two or more resin layers instead of a single resin, and three or more resin powders may be mixed in the crushed material. In such a case, in order to separate three or more types of resins contained in the crushed material, electrostatic separation may be performed twice or more by appropriately changing the electrostatic separation conditions such as the applied voltage.

Further, in the above-described embodiment, as the separation step, the case where the air separation is first performed and then the electrostatic separation is performed has been described, but the present invention is not limited to this. For example, the crushed material may be subjected to electrostatic screening as it is. Pneumatic sorting may be performed on each of the powders preferably separated by electrostatic sorting. This point will be specifically described below.

The crushed material contains powder derived from solar cells 11, metal patterns 12, sealing material 13, and protective member 14, as described above. The crushed material is electrostatically sorted by setting the voltage between the electrodes so that at least the resin powder derived from the sealing material 13 and the resin powder derived from the protective member 14 can be separated. As a result, first, the powder group derived 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. . Subsequently, among the powder group containing the resin powder derived from the sealing material 13 and the powder group containing the resin powder derived from the protective member 14, the powder having relatively high conductivity and low insulation is the low insulation powder. Separated as a body.
Finally, the high insulation will be separated as a high insulation powder. Specifically, when the sealing material 13 is made of EVA and the protective member 14 is made of PET, the metal powder is first separated, and then the resin powder derived from the sealing material 13 is reduced. Insulating powder is separated, and finally, resin powder derived from the protective member 14 is separated as highly insulating powder. In this way, by electrostatically sorting the crushed material as it is, the conductive powder, the low-insulation powder, and the high-insulation powder can be separated.

Subsequently, it is preferable to wind-screen each of the low-insulation powder and the high-insulation powder separated by electrostatic screening. This is because the powder derived from the solar cell 11 and the metal pattern 12 is separated by the above-described electrostatic separation, but may be mixed with the low-insulation powder and the high-insulation powder. By subjecting each of the low-insulation powder and the high-insulation powder to air sorting, it is possible to separate the powder derived from the metal pattern 12 as a heavy material and the resin powder as a light material. As described above, the sealing material 13 and the protective member 14 can be separately recovered while recovering valuable metals, similarly to the above-described embodiment.

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

(Example 1)
As an object to be treated, a solar cell sheet-like structure (PV sheet) was prepared by removing the glass substrate and the frame member from the solar cell module. In the PV sheet, the sealing material was made of EVA resin, and the protective member was made of PET. Subsequently, the PV sheet was crushed using a nugget machine. At this time, the crushed material was crushed until it passed through a 3 mm screen, and when it did not pass, the treatment was repeated. As the nugget machine, a uniaxial cutter mill "SKC-25-540L" was used. As crushing conditions, the number of blades was adjusted to 45, the clearance was about 2 mm, and the rotation speed of the blades was adjusted to 630 rpm. In addition, "APS-250RB" was used as the wind sorter.

Subsequently, the crushed PV sheets having a particle size of 3 mm or less were subjected to wind separation at a wind speed of 20 m/s. As a result, heavy items and light items were separated. The heavy objects mainly contained valuable metals and powder derived from solar cells. The lightweight materials included EVA powder (black) derived from the sealing material, PET powder (white) derived from the protective member, and the like.

Subsequently, the lightweight material containing the resin powder was subjected to electrostatic sorting. Specifically, using an electrostatic sorting apparatus, electrostatic sorting was performed under the conditions of an applied voltage of 19 kV and a drum rotation speed of 20 rpm. As a result, first, EVA powder, which is difficult to be charged and is electrically conductive, that is, as low-insulating powder, is detached from the grounded metal drum electrode and dropped into a separation container installed below the grounded metal drum electrode. collected separately. Subsequently, the easily charged non-conductive powder, that is, the PET powder as a highly insulating powder, is rotated with the grounded metal drum while remaining adhered to the grounded metal drum, and is physically removed by a brush attached to the grounded metal drum. , separated and collected in a separation container installed below the brush. Also, the powder collected in each separation container was subjected to electrostatic sorting three times to collect low-insulation powder and high-insulation powder, respectively.

In order to confirm that the resin can be separated by type in this example, the following evaluation was performed. Specifically, the light weight before electrostatic sorting, the sample that fell from the grounded metal drum electrode during the electrostatic separation of the light weight, and the adhered sample collected by the brush while adhering to the grounded metal drum electrode. , the ratio of EVA powder, which is a low-insulation powder, to PET powder, which is a high-insulation powder, was obtained. This ratio was calculated from the area ratio of each region by performing image analysis on each sample, regarding the white PET powder as a white region and the black EVA powder as a black region.

As a result, it was confirmed that the lightweight material before electrostatic sorting contained PET powder at a ratio of 6% and EVA powder at a ratio of 94% per unit area. It was also confirmed that the dropped sample contained 1% PET powder and 99% EVA powder per unit area. It was also confirmed that the attached sample contained 8% PET powder and 92% EVA powder per unit area. The ratio of PET powder can be as low as 1% in the falling sample, and as high as 8% in the adhered sample. It was confirmed that the PET powder can be efficiently separated as a highly insulating powder because the PET powder can be concentrated by setting the height higher than the above.

Reference Signs List 1 solar cell module 10 solar cell sheet structure 11 solar cell 12 metal pattern 13 sealing material 14 protective member 15 glass substrate 16 frame member

Claims (6)

The glass substrate and the frame member are removed from the solar cell module, and at least the solar cell, the metal pattern wired from the solar cell, the resin sealing material for sealing these, and the sealing material. A preparation step of preparing a solar cell sheet-like structure comprising a resin protective member provided on one surface;
A crushing step of shearing and crushing the solar cell sheet-like structure with a uniaxial crusher to crush each member into a size corresponding to its material, and forming a crushed material containing powder derived from each member;
a separation step of subjecting the crushed material to electrostatic sorting and wind sorting, and separating the powder by type of metal and resin;
The crushed material contains at least one of powder containing a semiconductor material derived from the solar cell, metal powder derived from the metal pattern, ethylene-vinyl acetate copolymer derived from the sealing material, and polyethylene. and resin powder containing at least one of polyethylene terephthalate and fluororesin derived from the protective member, each powder having a size corresponding to its material,
In the separation step, the crushed material is sorted by wind power as it is, and the powder contained in the crushed material is sorted by wind power according to weight into heavy items , resin powder derived from the sealing material, and the protective member. After separating the resin powder derived from the resin powder and the light weight substance containing the resin powder, the light weight substance is electrostatically sorted by corona discharge to obtain the resin powder derived from the sealing material and the resin powder derived from the protective member. separates the body according to differences in chargeability and conductivity,
A method of processing a solar cell module. In the separation step, after the powder contained in the crushed material is separated into heavy materials and other light materials by wind sorting, the light materials are electrostatically sorted to obtain low-insulating powder having a low volume resistivity. separated into a solid and a highly insulating powder with a relatively high volume resistivity,
The method for treating a solar cell module according to claim 1. In the separation step, wind separation is performed at a wind speed of 5 m / s or more and 20 m / s or less,
The method for treating a solar cell module according to claim 1 or 2. In the separation step, electrostatic selection is performed with a voltage of 10 kV or more and 30 kV or less applied to the electrodes.
The method for treating a solar cell module according to any one of claims 1 to 3. In the crushing step, the solar cell sheet-like structure is crushed so that the particle size of the crushed material is 20 mm or less.
The method for treating a solar cell module according to any one of claims 1 to 4. The separation step uses an electrostatic sorting device with a grounded metal drum electrode,
The method for treating a solar cell module according to any one of claims 1 to 5.

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