Method for separating waste solar panels

Abstract

This invention provides a separation method that enables the fragmentation and recovery of various materials contained in discarded solar panels. [Solution] The waste solar panel separation method according to the present invention comprises a crushing step of crushing the solar panel to be discarded into fragments, and a specific gravity separation step of separating the fragments generated after the crushing step according to their specific gravity by applying wind power. Preferably, the waste solar panel separation method comprises a magnetic separation step of further subdividing and sorting the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step according to the presence or absence of magnetism.

Description

Technical Field

[0001] In recent years, due to concerns about environmental issues, the awareness of recycling has been increasing globally. Therefore, technologies for separating and recycling reusable substances from waste solar panels have attracted attention.

Background Art

[0002] As an example of such a technology, Patent Document 1 discloses a method for separating precious metals from a waste solar panel. Specifically, Patent Document 1 discloses a separation device for solar panels for a heated target solar panel part which is a part of the waste solar panel to be discarded. The heated target solar panel part has a plurality of solar cell units sealed by a remaining sealing material. The separation device for solar panels includes a first transport mechanism for transporting the heated target solar panel part, and a first heating mechanism for performing a first local heating treatment of locally heating a first heating target area at a first temperature with respect to the remaining sealing material of the heated target solar panel part transported by the first transport mechanism. The first heating target area includes a contact area between the remaining sealing material and the plurality of solar cell units. The first local heating treatment is performed in a non-contact state with the heated target solar panel part. The first temperature is set to a temperature at which the remaining sealing material decomposes. Each of the plurality of solar cell units has a precious metal forming area provided with a precious metal on its surface. The separation device for solar panels further includes a second transport mechanism for transporting the plurality of solar cell units in an independent state in cell units, and a second heating mechanism for performing a second local heating treatment of locally heating a second heating target area at a second temperature with respect to each of the plurality of solar cell units transported by the second transport mechanism. The second heating target area includes the precious metal forming area. The second local heating treatment is performed in a non-contact state with each of the plurality of solar cell units. The second temperature is set to a temperature at which the precious metal melts, and the first temperature is set to a temperature at which the precious metal does not melt.

Prior Art Documents

Patent Documents

[0003] [Patent Document 1] Patent No. 7214326 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The separation method described in Patent Document 1 has the advantage of being able to separate multiple solar cells and to dissolve, separate, and recover the precious metals contained in each solar cell. However, the aforementioned document does not disclose a means for further separating and recovering the separated and recovered precious metals into individual substances, and further improvements were desired.

[0005] The object of the present invention is to provide a separation method that makes it possible to further subdivide and recover each substance contained in waste solar panels. [Means for solving the problem]

[0006] The method for separating waste solar panels according to the present invention is characterized by comprising a crushing step of crushing the solar panels to be discarded into fragments, and a specific gravity separation step of separating the fragments generated after the crushing step according to their specific gravity by applying wind power.

[0007] According to this method, each substance contained in waste solar panels can be recovered in a more finely broken-down manner than before, contributing to the more appropriate reuse of each substance.

[0008] Furthermore, in the method for separating waste solar panels according to the present invention, it is preferable to have a magnetic separation step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is further subdivided and sorted based on the presence or absence of magnetism.

[0009] According to this method, magnetic materials such as metal alloys and non-magnetic materials such as glass and silicon can be separated, sorted, and then recovered, thereby contributing even more to recycling.

[0010] Furthermore, in the method for separating waste solar panels according to the present invention, it is preferable to have a color sorting step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is further subdivided and sorted according to differences in color.

[0011] According to this method, the processed material separated from waste solar panels can be further subdivided and collected based on differences in color, which can then be used for recycling.

[0012] Furthermore, in the method for separating waste solar panels according to the present invention, it is preferable to have a metal detection and sorting step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is further subdivided and sorted using a metal detector.

[0013] According to this method, the processed material separated from waste solar panels can be further subdivided and recovered based on detection results from a metal detector, and can be used for recycling.

[0014] Furthermore, in the method for separating waste solar panels according to the present invention, it is preferable to further include a high-frequency induction heating step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is subjected to high-frequency induction heating.

[0015] According to this method, after separating and recovering the treated material from waste solar panels, dioxins can be detoxified by thermal decomposition, making it possible to use the treated material for recycling more safely. [Effects of the Invention]

[0016] According to the separation method of the present invention, it is possible to further subdivide and recover each substance contained in waste solar panels. [Brief explanation of the drawing]

[0017] [Figure 1]It is a diagram schematically explaining each step of the method for separating waste solar panels according to an embodiment of the present invention. [Figure 2] It is a diagram showing details of the pulverization step among the methods for separating waste solar panels according to an embodiment of the present invention. [Figure 3] It is a diagram showing details of the specific gravity separation step among the methods for separating waste solar panels according to an embodiment of the present invention. [Figure 4] It is a diagram showing steps after the specific gravity separation step among the methods for separating waste solar panels according to an embodiment of the present invention. [Figure 5] It is a diagram showing details of the magnetic separation step among the methods for separating waste solar panels according to an embodiment of the present invention. [Figure 6] It is a diagram showing details of the high-frequency induction heat treatment among the methods for separating waste solar panels according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following, the same reference numerals are given to the same elements in all the drawings, and duplicate explanations are omitted. Also, in the description in the text, the reference numerals described above will be used as necessary.

[0019] First, the separation method according to the present invention, which is used to pulverize and subdivide a waste solar panel (hereinafter sometimes referred to as a waste solar panel) to be discarded for recycling, will be described with reference to FIGS. 1 to 5.

[0020] FIG. 1 is a diagram schematically explaining each step of the method for separating waste solar panels according to an embodiment of the present invention.

[0021] As shown in FIG. 1, the method for separating waste solar panels according to an embodiment of the present invention includes a pulverization step, a specific gravity separation step, a color sorting step, a metal detection sorting step, a magnetic separation step, and a high-frequency induction heating step. Hereinafter, each of these steps will be described in order.

[0022] <Grinding process> Figure 2 shows details of the crushing step in the method for separating waste solar panels S according to an embodiment of the present invention. In detail, the crushing step includes a primary crushing step in which the panels are crushed by a twin-shaft shredder, and a secondary crushing step in which the panels are crushed by a single-shaft shredder.

[0023] In the crushing process, first, the waste solar panels S are placed sequentially on the conveying surface by an operator at the upstream end of the first conveyor 10. The waste solar panels S that reach the downstream end of the first conveyor 10 are fed into the first box 60, which houses the twin-shaft shredder 61.

[0024] The twin-shaft shredder 61 consists of a first rotating blade 61a and a second rotating blade 61b that rotate in opposite directions. The waste solar panels S fed into the first box 60 are roughly crushed into coarse fragments by the action of the first rotating blade 61a and the second rotating blade 61b. Depending on the shape and spacing of the first rotating blade 61a and the second rotating blade 61b, the size of the coarse fragments P1 after processing may be, for example, 100 mm or less.

[0025] The lower end of the first box 60 is open, and the coarse fragments P1 fall naturally to the upstream end of the second conveyor 20 by gravity and are placed on the conveying surface of the second conveyor 20. The conveying surface of the second conveyor 20 is configured as a mesh of 20-60 mm, preferably 25-55 mm, and more preferably 30-50 mm. In this embodiment, the conveying surface of the second conveyor 20 is a 30 mm mesh, and the coarse fragments P1 are filtered out on this conveying surface, so that only coarse fragments P1 of a size of 30 mm to 50 mm or larger are supplied to the single-shaft shredder 71. This promotes the efficiency of shredding. The coarse fragments P1 that reach the downstream end of the second conveyor 20 fall naturally into the second box 70 and are fed in. The single-shaft shredder 71 is housed inside the second box 70.

[0026] The single-shaft shredder 71 comprises a rotating blade 71a that rotates in one direction and a curved particle size adjustment screen 71b positioned to cover the lower half of the rotating blade 71a from below. The particle size adjustment screen 71b has a mesh structure of appropriate coarseness according to the desired size of the fragments after shredding. The shape of the blades of the rotating blade 71a depends on the spacing between them and the coarseness of the mesh, but the size of the fragments after processing by the single-shaft shredder 71 may be, for example, 10 mm or less. The processed fragments obtained in this way are placed on the conveying surface of the third conveyor 30, which is inclined to become higher towards the downstream side, and transported to the next process, the specific gravity separation process. Specifically, the fragments transported to the downstream end of the third conveyor 30 are allowed to fall naturally and are supplied to the inlet 80a of the air-powered specific gravity separator 80.

[0027] <Specific gravity separation process> Figure 3 shows the details of the specific gravity separation step in the method for separating waste solar panels S according to an embodiment of the present invention. In the specific gravity separation step, as shown in Figure 3, the fragments P2 obtained through the crushing step are supplied to the wind-powered specific gravity separator 80. The wind-powered specific gravity separator 80 is composed of a cylindrical body 81 positioned in an inclined position such that the upstream side is higher than the downstream side, a wind power source 82 positioned at the downstream end of the cylindrical body 81, a vibration motor 83 provided to vibrate the cylindrical body 81, and heavy object drop-off ports 81a, medium object drop-off ports 81b, and light object drop-off ports 81c arranged sequentially from downstream to upstream at the bottom of the cylindrical body. The cylindrical body 81 is supported by a support 85 via a spring 84, so that the cylindrical body 81 vibrates in response to vibrations generated by the vibration motor 83.

[0028] When the fragments P2 obtained through the crushing process are supplied into the cylindrical body 81, the fragments are blown away by the wind from the wind source 82 and vibrations applied by the vibration motor 83, causing each fragment to fall unevenly at appropriate locations within the cylindrical body 81 according to its specific gravity. Specifically, fragments categorized as heavy fall downward from the heavy object drop-off opening 81a, fragments with a relatively lower specific gravity than the heavy objects fall downward from the medium-weight object drop-off opening 81b, and fragments with an even relatively lower specific gravity than the medium-weight objects fall downward from the small object drop-off opening 81c. The fragments that fall from each drop-off opening 81a, 81b, and 81c are separated and collected in a collection box that is pre-positioned below the drop-off opening.

[0029] <Color sorting process> The processed materials separated into groups with relatively high specific gravity, specifically, those classified as heavy and medium weight in this embodiment, are placed by the operator at the upstream end of the horizontal conveyor 50. In other words, the fragments separated as light materials (plastic, rubber, film, etc.) can be reused as building materials in their current state, and are therefore separated and collected in this state. The fragments classified into other groups (medium weight and heavy weight) are further subdivided for collection, and are therefore placed individually on the horizontal conveyor 50 for subsequent processing.

[0030] The fragments placed on the horizontal conveyor 50 are processed by the color sorter 130 shown in Figure 4, separating them according to their color differences. This makes it possible to separate and sort glass fragments and other materials that could not be separated by specific gravity separation alone after crushing.

[0031] <Metal detection process> After the color sorting process, the fragments are then processed by the metal detector 90 shown in Figure 4, separating them according to whether they are metal or not. This allows for rough sorting of the waste solar panel fragments according to whether they are metal or not in a step prior to magnetic sorting, resulting in the realization of a more advanced material cycle. In this embodiment, in addition to the detection results from the metal detection process, visual sorting by an operator is also performed to improve accuracy, and an operator is always on standby downstream of the metal detector 90.

[0032] <Magnetic separation process> A magnetic separation mechanism 100, as shown in Figure 4, is located at the downstream end of the horizontal conveyor 50. As shown in Figure 5, the magnetic separation mechanism 100 comprises a rotating body 101 made of magnets and a branching plate 102 for separating fragments attracted to the rotating body 101 by magnetic force from other fragments. As a result, the fragments supplied to the magnetic separation mechanism 100 are separated into magnetic materials (e.g., iron and iron-containing alloys) and non-magnetic materials (e.g., glass, silicon, etc.) by the interaction of the rotating body 101 and the branching plate 102. Figure 5 shows the details of the magnetic separation process in the waste solar panel separation method of this embodiment.

[0033] <High-frequency induction heating process> Each fragment, separated through a color sorting process, a metal detection process, and a magnetic sorting process, is subjected to high-frequency induction heating according to the dissolution and separation temperature of each substance. The heating device 120, which performs high-frequency induction heating, is equipped with a known auxiliary device 121 used for measures to suppress dioxin emissions. This allows for the thermal decomposition of dioxins and the detoxification of those dioxins based on the treatment by the auxiliary device 121. As a result, the safety and convenience of the fragments produced for recycling when they are reused as building materials or other materials can be improved.

[0034] As described above, the method for separating waste solar panels according to this embodiment comprises a crushing step of crushing the solar panel S to be discarded into fragments, and a specific gravity separation step of separating the fragments generated through the crushing step according to their specific gravity by applying wind power.

[0035] According to this method, each substance contained in the waste solar panel S can be recovered in a more finely broken-down manner than before, contributing to recycling.

[0036] Furthermore, the separation method for waste solar panels S according to this embodiment includes a magnetic separation step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is further subdivided and sorted based on the presence or absence of magnetism.

[0037] According to this method, iron and iron-containing alloys can be separated and sorted from non-magnetic materials such as glass and silicon before being recovered, thus contributing even more to recycling.

[0038] Furthermore, the separation method for waste solar panels S according to this embodiment includes a color sorting step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is further subdivided and sorted according to differences in color.

[0039] According to this method, the treated material separated from the waste solar panel S can be further subdivided and recovered based on differences in color. Typically, each substance contained in the waste solar panel S exhibits a different color depending on its composition. By separating each substance according to its color, it becomes possible to reuse each substance using a more suitable recycling method.

[0040] Furthermore, the separation method for waste solar panels S according to this embodiment includes a metal detection and sorting step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is further subdivided using a metal detector 90. Generally, by classifying each substance contained in the waste solar panels S according to whether or not it is a metal, it becomes possible to separate and recover each substance more finely. As a result, each substance can be reused for a more appropriate purpose.

[0041] According to this method, the processed material separated from the waste solar panels S can be further subdivided and recovered based on the detection results of the metal detector 90, and can be used for recycling.

[0042] Furthermore, the separation method for waste solar panels S according to this embodiment further includes a high-frequency induction heating step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is subjected to high-frequency induction heating.

[0043] According to this method, after the treated material separated from the waste solar panels S is subdivided and recovered, the dioxins can be detoxified by thermal decomposition, making it possible to use the treated material for recycling more safely. In addition, to reliably suppress the emission of dioxins, a cooling tower or dust collector may be installed in the high-frequency induction heating device 120.

[0044] As a result, the waste solar panel S separation method according to this embodiment allows for the sorting of fragments generated by crushing the waste solar panel S from multiple perspectives, including differences in specific gravity, color, whether or not they are metallic, and differences in magnetic force. This contributes to a higher level of recycling of the materials (including valuable precious metals) contained in the waste solar panel S.

[0045] Furthermore, if a separation method like the present invention is applied to waste solar panels during processing, based on the main components and process charts of solar panels published by the manufacturers of solar panels used in large-scale solar power plants, for example, it can lead to a significant improvement in the recycling rate of said waste solar panels, which is advantageous.

[0046] In this embodiment, the separation method for waste solar panels S was described as separating the treated material after the specific gravity separation step using a color sorting step, a metal detection step, and a magnetic sorting step. However, these steps may be appropriately selected depending on the treated material. [Explanation of Symbols]

[0047] S Waste solar panels, 61 Twin-shaft shredder, 71 Single-shaft shredder, P1 Coarse fragments, P2 Fragments, 80 Wind-powered specific gravity separator, 130 Color sorter, 90 Metal detector, 100 Magnetic separation mechanism

Claims

1. A crushing process in which solar panels to be discarded are crushed into fragments, A specific gravity separation step is performed to separate the fragments generated after the crushing step by applying wind power to them according to their specific gravity, A method for separating waste solar panels, characterized by having [a certain feature].

2. In the method for separating waste solar panels according to claim 1, A method for separating waste solar panels, characterized by having a magnetic separation step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is further subdivided and sorted based on the presence or absence of magnetism.

3. In the method for separating waste solar panels according to claim 1, A method for separating waste solar panels, characterized by having a color sorting step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is further subdivided and sorted according to differences in color.

4. In the method for separating waste solar panels according to claim 1, A method for separating waste solar panels, characterized by having a metal detection and sorting step in which the processed material separated as a group with a relatively high specific gravity in the specific gravity separation step is further subdivided and sorted using a metal detector.

5. In the method for separating waste solar panels according to claim 1, A method for separating waste solar panels, further comprising a high-frequency induction heating step in which the processed material separated as a group with a relatively high specific gravity in the aforementioned specific gravity separation step is subjected to high-frequency induction heating.

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