A method for comprehensive recovery of all components of waste photovoltaic modules

Abstract

This invention belongs to the field of photovoltaic recycling, specifically relating to a method for the comprehensive recycling of waste photovoltaic modules, comprising: disassembling waste photovoltaic panels to separate photovoltaic laminates, aluminum frames, and junction boxes; crushing the photovoltaic laminates to obtain photovoltaic crushed material; subjecting the photovoltaic crushed material to a decomposition reaction to break down the EVA adhesive into non-adhesive molecules; sorting the decomposition reaction-treated photovoltaic crushed material to separate glass, plastic backsheets, and copper powder to obtain a silicon powder mixture; dissolving the silicon powder mixture to obtain a silver-containing solution and silicon powder precipitate; separating the silicon powder precipitate and converting the silver-containing solution into elemental silver for recycling. This invention performs in-depth processing based on physical sorting, further purifying the silicon powder while obtaining valuable metallic silver, increasing economic benefits, reducing recycling costs, and achieving efficient and green recycling of photovoltaic modules.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic recycling, specifically, it relates to a method for the comprehensive recycling of waste photovoltaic modules. Background Technology

[0002] Currently, the main methods for recycling waste photovoltaic modules include thermal treatment, mechanical treatment, and chemical treatment. Thermal treatment uses high temperatures to remove organic matter from the modules and recover intact photovoltaic glass and silicon wafers, but it releases toxic gases. Mechanical treatment uses mechanical equipment to crush and screen the modules for green recycling, but it damages the solar cells and hinders the separation of components. Chemical treatment uses solvents to separate and recover components from the laminates, but the tight bonding between the layers of the solar panel results in long reaction times and difficulties in waste liquid treatment.

[0003] Currently, the mainstream trend in the recycling of waste crystalline silicon photovoltaic modules is resource-based and harmless recycling throughout their entire life cycle. Mechanical processing has become the mainstream method for recycling waste crystalline silicon photovoltaic modules due to its environmental friendliness. However, the purity of products obtained by mechanical processing is currently low, only meeting the needs of the lower-end market. With technological advancements, the market's requirements for the purity of glass and silicon wafers in photovoltaic modules are further increasing. If mechanical processing is still used, deep sorting equipment needs to be added, making the mechanical processing process too long and increasing energy consumption. In the future, the recycling of retired photovoltaic modules will tend towards low-energy consumption, green and efficient processing methods. At the same time, higher requirements will be placed on the recovery rate, purity, and integrity of recycled glass, silicon powder, etc. In addition, less attention has been paid to the recycling of silver, which is of high value in retired photovoltaic modules. Most recycling methods mix silver with silicon powder, which not only loses valuable silver but also reduces the purity of the recycled silicon powder. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the prior art and to propose a method for the comprehensive recycling of waste photovoltaic modules.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A method for comprehensive recycling of waste photovoltaic modules, comprising:

[0007] The waste photovoltaic panels are disassembled to separate photovoltaic laminates, aluminum frames and junction boxes;

[0008] The photovoltaic laminate is crushed to obtain photovoltaic crushed material;

[0009] The photovoltaic crushed material is subjected to a decomposition reaction treatment, which breaks down the EVA adhesive in the photovoltaic crushed material into non-adhesive molecules.

[0010] The photovoltaic fragments after the decomposition reaction are sorted to separate glass, plastic backsheet and copper powder, resulting in a silicon powder mixture.

[0011] The silicon powder mixture is dissolved to obtain a silver-containing solution and silicon powder precipitate. After separating the silicon powder precipitate, the silver-containing solution is converted into elemental silver for recovery.

[0012] Optionally, the crushing of the photovoltaic laminate includes:

[0013] The photovoltaic laminate is placed in a crusher for crushing and cutting to form photovoltaic crushed materials with regular shapes and similar or identical sizes.

[0014] Optionally, the size range of the photovoltaic crushed material is 2cm-10cm.

[0015] Optionally, the decomposition reaction treatment of the photovoltaic crushed material includes:

[0016] Photovoltaic shredded EVA was placed in a decomposition reaction device for EVA decomposition treatment. The temperature of the EVA decomposition treatment was 40℃-150℃, the treatment pressure was 8MPa, and the treatment time was 10min-60min.

[0017] Optionally, the sorting process for the photovoltaic shredded material after decomposition reaction includes:

[0018] Glass is separated from photovoltaic rubble using a color sorter.

[0019] Copper powder is separated from photovoltaic crushed material by airflow separator.

[0020] The plastic backsheet in the photovoltaic crushed material is separated by an electrostatic separator.

[0021] After separating the glass, copper powder, and plastic backing, a mixture of silicon powder is obtained.

[0022] Optionally, when sorting by color sorter, the sorting accuracy is 0.01mm.

[0023] Optionally, the process of dissolving the silicon powder mixture includes:

[0024] The silicon powder mixture was put into a reaction vessel, and a dilute nitric acid solution was added as a dissolving agent to carry out the dissolution reaction. The silicon powder precipitate was obtained by filtration.

[0025] Optionally, when adding dilute nitric acid solution as a dissolving agent for the dissolution reaction, the dissolving agent and the silicon powder mixture are stirred by a stirring device in the reaction vessel.

[0026] Optionally, after the separated silicon powder precipitates, the separated silicon powder is placed in a drying device for drying treatment.

[0027] Optionally, the process of converting the silver-containing solution into elemental silver for recovery includes:

[0028] The silver-containing solution is placed in an electrolytic cell, and an electric current is applied to reduce the silver ions in the silver-containing solution to elemental silver.

[0029] The present invention has the following beneficial effects:

[0030] This invention provides a comprehensive method for recycling waste photovoltaic modules. Based on physical sorting, it performs in-depth processing to further purify silicon powder and obtain valuable metallic silver. This improves the recovery rate and purity of each component and can recover valuable silicon powder and photovoltaic glass more completely, increasing economic benefits, reducing recycling costs, and achieving the effect of efficient and green recycling of photovoltaic modules.

[0031] The advantages of this invention are:

[0032] 1. Placing photovoltaic crushed materials in an EVA decomposition reaction device for EVA decomposition treatment avoids the high energy consumption and high pollution processes of using high-temperature pyrolysis of EVA or chemical reagents, greatly reducing the energy consumption of the production line, and does not produce toxic gases, reducing the generation of waste, improving the economic efficiency of industrial enterprises, and providing feasibility for the construction of subsequent production lines and facilitating on-site processing of photovoltaic modules.

[0033] 2. Using automated disassembly equipment to remove the aluminum frame and junction box yields a complete aluminum frame and junction box;

[0034] 3. Using color sorting to recycle glass, the recycling efficiency can reach over 95%. Through airflow separation and electrostatic separation, the recovery rate of solder ribbon (copper) and silicon powder can reach over 98%.

[0035] 4. While purifying silicon powder, metallic silver is recovered. After further processing, the silver recovery rate can reach over 85%.

[0036] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0037] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0038] Figure 1 A flowchart illustrating a method for comprehensive recycling of waste photovoltaic modules based on all components, as provided in this embodiment of the invention;

[0039] Figure 2 This is a process flow diagram of sorting photovoltaic crushed material after decomposition reaction provided by an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of a precision crusher provided in an embodiment of the present invention. Figure 1 ;

[0041] Figure 4 A schematic diagram of a precision crusher provided in an embodiment of the present invention. Figure 2 ;

[0042] Figure 5 A cross-sectional view of a precision crusher provided in an embodiment of the present invention;

[0043] Figure 6 A partial schematic diagram of a precision crusher provided in an embodiment of the present invention;

[0044] Figure 7 A schematic diagram of the frame and crushing chamber provided in an embodiment of the present invention;

[0045] Figure 8 This is a schematic diagram of a cylindrical filter screen provided in an embodiment of the present invention;

[0046] Figure 9 A schematic diagram of the crusher wheel structure provided in an embodiment of the present invention;

[0047] Figure 10 A schematic diagram of the upper transmission wheel structure provided in an embodiment of the present invention;

[0048] Figure 11 This is a schematic diagram of the lower transmission wheel structure provided in an embodiment of the present invention;

[0049] Figure 12 A schematic diagram of the filter transmission structure provided in an embodiment of the present invention;

[0050] Figure 13 A schematic diagram of the filter cleaning structure provided in an embodiment of the present invention;

[0051] Figure 14 A cross-sectional view of the filter cleaning structure provided in an embodiment of the present invention;

[0052] Figure 15 This is a schematic diagram of a sieve vibration structure provided in an embodiment of the present invention. Detailed Implementation

[0053] The following description and accompanying drawings fully illustrate specific embodiments described herein to enable those skilled in the art to practice them. Some embodiments may include or substitute parts and features of other embodiments. The scope of the embodiments herein encompasses the entire scope of the claims and all available equivalents thereof. Throughout this document, the terms “first,” “second,” etc., are used only to distinguish one element from another without requiring or implying any actual relationship or order between the elements. Indeed, a first element can also be referred to as a second element, and vice versa. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a structure, apparatus, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a structure, apparatus, or device. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the structure, apparatus, or device that includes said element. The various embodiments described herein are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments; similar or identical parts between embodiments can be referred to interchangeably.

[0054] The terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used in this document to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They are used solely for the convenience of describing the document and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description herein, unless otherwise specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two elements; they can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0055] In this document, unless otherwise stated, the term "multiple" means two or more.

[0056] In this article, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0057] In this article, the term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0058] The following is in conjunction with the appendix Figure 1-15The present invention will be further described in detail below. Unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0059] like Figure 1-2 As shown, a method for comprehensive recycling of waste photovoltaic modules includes:

[0060] The waste photovoltaic panels are disassembled to separate photovoltaic laminates, aluminum frames and junction boxes;

[0061] The photovoltaic laminate is crushed to obtain photovoltaic crushed material;

[0062] The photovoltaic crushed material is subjected to a decomposition reaction treatment, which breaks down the EVA adhesive in the photovoltaic crushed material into non-adhesive molecules.

[0063] The photovoltaic fragments after the decomposition reaction are sorted to separate glass, plastic backsheet and copper powder, resulting in a silicon powder mixture.

[0064] The silicon powder mixture is dissolved to obtain a silver-containing solution and silicon powder precipitate. After separating the silicon powder precipitate, the silver-containing solution is converted into elemental silver for recovery.

[0065] This invention discloses a comprehensive method for recycling waste photovoltaic (PV) modules. First, the waste PV modules are disassembled using automated dismantling equipment, yielding relatively intact aluminum frames and junction boxes for easy recycling. Next, the PV laminates are crushed to ensure regular and uniform crushing. The crushed PV material then undergoes a decomposition reaction treatment, breaking down the EVA adhesive into non-adhesive molecules. This invention avoids the high energy consumption and pollution associated with high-temperature pyrolysis of EVA or chemical reactions, significantly reducing production line energy consumption and eliminating the generation of toxic gases, thus minimizing waste. After removing the EVA adhesive from the photovoltaic crushed material, the material undergoes physical sorting to separate glass, plastic backsheets, and copper powder, resulting in a silicon powder mixture. This mixture is then dissolved to obtain a silver-containing solution and silicon powder precipitate. After separating the precipitate, the silver-containing solution is converted into elemental silver for recovery. This process allows for the relatively complete recovery of high-value silicon powder and photovoltaic glass, increasing economic benefits, reducing recycling costs, and achieving efficient and green recycling of photovoltaic modules. Simultaneously, metallic silver is recovered during silicon powder purification, and after further processing, the silver recovery rate can reach over 85%.

[0066] The process of crushing the photovoltaic laminate includes:

[0067] The photovoltaic laminate is placed in a crusher for crushing and cutting to form photovoltaic fragments with regular shapes and similar sizes. Crushing the photovoltaic laminate into photovoltaic fragments with regular shapes and similar sizes prevents the photovoltaic laminate from being too large, which would reduce recycling efficiency or increase supercritical processing time.

[0068] The size range of the photovoltaic crushed material is 2cm-10cm, which effectively avoids the drawback of the useful components being difficult to separate due to over-crushing during the crushing process.

[0069] The process of decomposing and reacting photovoltaic fragments includes:

[0070] Photovoltaic shredded EVA was placed in a decomposition reaction device for EVA decomposition treatment. The temperature of the EVA decomposition treatment was 40℃-150℃, the treatment pressure was 8MPa, and the treatment time was 10min-60min.

[0071] The process of sorting the photovoltaic crushed material after decomposition reaction includes:

[0072] Glass is separated from photovoltaic rubble using a color sorter. The sorting accuracy is 0.01mm, which makes the glass sorting efficiency reach more than 95%.

[0073] The copper powder in the photovoltaic crushed material is separated by an air classifier. The copper powder is collected from the bottom of the air classifier as a heavy material, while silicon powder and other materials are collected from the top of the air classifier as light materials.

[0074] The plastic backsheets in the photovoltaic crushed material are separated by an electrostatic separator. The electrostatic separation method separates silicon powder from the backsheets based on their conductivity. The speed and intensity of the electrostatic separation are adjusted according to the differences in the properties of the silicon powder.

[0075] After separating the glass, copper powder, and plastic backing, a mixture of silicon powder is obtained.

[0076] The process of dissolving the silicon powder mixture includes:

[0077] The silicon powder mixture was put into a reaction vessel, and a dilute nitric acid solution was added as a dissolving agent to carry out the dissolution reaction. The silicon powder precipitate was obtained by filtration.

[0078] When dilute nitric acid solution is added as a dissolving agent for the dissolution reaction, the dissolving agent and the silicon powder mixture are stirred by a stirring device inside the reaction vessel.

[0079] After the separated silicon powder precipitates, it is placed in a drying equipment for drying to obtain high-purity silicon powder for downstream applications or for secondary purification in the photovoltaic industry.

[0080] The process of converting the silver-containing solution into elemental silver for recovery includes:

[0081] A silver-containing solution is placed in an electrolytic cell, and an electric current is applied to reduce the silver ions in the solution to elemental silver. During the electrolytic treatment of the silver-containing solution, the silver ions are reduced to elemental silver at the cathode by the application of current, while oxygen is generated at the anode. Simultaneously, the electrolyzed solution can be recycled.

[0082] To facilitate understanding of the above technical solutions of the present invention, the following detailed embodiments will further illustrate the above technical solutions of the present invention.

[0083] Example 1

[0084] The present invention provides a method for the comprehensive recycling of waste photovoltaic modules, which includes the following steps in the dismantling of waste photovoltaic panels:

[0085] (1) Using automatic dismantling equipment to remove the aluminum frame and junction box of waste photovoltaic panels can not only obtain the complete aluminum frame and junction box, but also prevent them from entering the subsequent sorting steps and reducing sorting efficiency.

[0086] (2) The photovoltaic laminate with the aluminum frame and junction box removed is regularly crushed, with a crushing size of 10cm.

[0087] (3) The broken photovoltaic laminate is placed in an EVA decomposition reaction device. The reaction temperature is set to 40℃, the pressure to 8MPa, and the processing time to 10min. Under these conditions, the complex decomposes EVA into small molecules, thereby losing its stickiness. After the decomposition reaction, a mixture of glass, plastic backsheet, solder ribbon (copper), etc. is obtained.

[0088] (4) Use a color sorter with a sorting accuracy of 0.01mm to sort the mixture and separate the glass. The glass recovery rate can reach 97%, and the remaining material enters the airflow separation stage.

[0089] (5) Use an air classifier to separate the solder strip (copper). After the material enters the air classifier, under the action of wind, the silicon powder and plastic back plate enter the next sorting stage from the light component collector, while the solder strip enters the heavy component collector to complete the sorting process.

[0090] (6) Based on the difference in conductivity, the remaining silicon powder and plastic backing are separated by an electrostatic separator, and the recovery rate of the silicon powder mixture can reach 93%.

[0091] (7) Place the silicon powder mixture in a reaction vessel with a stirring device, add dilute nitric acid solution, the silver in the solution dissolves in the dilute nitric acid, filter the solution, dry the silicon powder precipitate, and the purity of the silicon powder after drying can reach 95%.

[0092] (8) The filtered solution is electrolyzed. During the electrolysis process, the silver nitrate solution is placed in the electrolytic cell, and the anode and cathode are connected to the positive and negative electrodes, respectively. By adding current, the anions are reduced to elemental silver at the cathode, and the silver recovery rate can reach 75%. The electrolyzed solution is then treated a second time to obtain a new dilute nitric acid solution, which is used as a supplementary solution for dissolving the silicon powder mixture.

[0093] Example 2

[0094] The present invention provides a method for the comprehensive recycling of waste photovoltaic modules, which includes the following steps in the dismantling of waste photovoltaic panels:

[0095] (1) Using automatic dismantling equipment to remove the aluminum frame and junction box of waste photovoltaic panels can not only obtain the complete aluminum frame and junction box, but also prevent them from entering the subsequent sorting steps and reducing sorting efficiency.

[0096] (2) The photovoltaic laminate with the aluminum frame and junction box removed is regularly crushed, with a crushing size of 2cm;

[0097] (3) The broken laminate is placed in an EVA decomposition reaction device, the reaction temperature is set to 40℃, the pressure is 8MPa, and the processing time is 10min. Under these conditions, the complex decomposes EVA into small molecules, thereby losing its stickiness. After the decomposition reaction, a mixture of glass, plastic backing, solder strip (copper), etc. is obtained.

[0098] (4) Use a color sorter with a sorting accuracy of 0.01mm to sort the mixture and separate the glass. The glass recovery rate can reach 95%, and the remaining material enters the airflow separation stage.

[0099] (5) Use an air classifier to separate the solder strip (copper). After the material enters the air classifier, under the action of wind, the silicon powder and plastic back plate enter the next sorting stage from the light component collector, while the solder strip enters the heavy component collector to complete the sorting process.

[0100] (6) Based on the difference in conductivity, the remaining silicon powder and plastic backing are separated by an electrostatic separator, and the recovery rate of the silicon powder mixture can reach 90%.

[0101] (7) Place the silicon powder mixture in a reactor equipped with a stirrer, add dilute nitric acid solution, the silver in the solution dissolves in the dilute nitric acid, filter the solution, and dry the silicon powder precipitate. After drying, the purity of the silicon powder can reach 93%.

[0102] (8) The filtered solution is electrolyzed. During the electrolysis process, the silver nitrate solution is placed in the electrolytic cell, and the anode and cathode are connected to the positive and negative electrodes, respectively. By adding current, the anions are reduced to elemental silver at the cathode, and the silver recovery rate can reach 77%. The electrolyzed solution is then treated a second time to obtain a new dilute nitric acid solution, which is used as a supplementary solution for dissolving the silicon powder mixture.

[0103] Example 3

[0104] The present invention provides a method for the comprehensive recycling of waste photovoltaic modules, which includes the following steps in the dismantling of waste photovoltaic panels:

[0105] (1) Using automatic dismantling equipment to remove the aluminum frame and junction box of waste photovoltaic panels can not only obtain the complete aluminum frame and junction box, but also prevent them from entering the subsequent sorting steps and reducing sorting efficiency.

[0106] (2) The photovoltaic laminate with the aluminum frame and junction box removed is regularly crushed, with a crushing size of 10cm.

[0107] (3) The crushed laminate was placed in an EVA decomposition reaction device. The reaction temperature was set to 80℃, the pressure to 8MPa, and the processing time to 30min. Under these conditions, the complex decomposed EVA into small molecules, thereby losing its stickiness. After the decomposition reaction, a mixture of glass, plastic backing, solder strip (copper), etc. was obtained.

[0108] (4) Use a color sorter with a sorting accuracy of 0.01mm to sort the mixture and separate the glass. The glass recovery rate can reach 98%, and the remaining material enters the airflow separation stage.

[0109] (5) Use an air classifier to separate the solder strip (copper). After the material enters the air classifier, under the action of wind, the silicon powder and plastic back plate enter the next sorting stage from the light component collector, while the solder strip enters the heavy component collector to complete the sorting process.

[0110] (6) Based on the difference in conductivity, the remaining silicon powder and plastic backing are separated by an electrostatic separator, and the recovery rate of the silicon powder mixture can reach 95%.

[0111] (7) Place the silicon powder mixture in a reactor equipped with a stirrer, add dilute nitric acid solution, and the silver in the solution dissolves in the dilute nitric acid. Filter the solution, and dry the silicon powder precipitate. After drying, the purity of the silicon powder can reach 98%.

[0112] (8) The filtered solution is electrolyzed. During the electrolysis process, the silver nitrate solution is placed in the electrolytic cell, and the anode and cathode are connected to the positive and negative electrodes, respectively. By adding current, the anions are reduced to elemental silver at the cathode, and the silver recovery rate can reach 85%. The electrolyzed solution is then treated a second time to obtain a new dilute nitric acid solution, which is used as a supplementary solution for dissolving the silicon powder mixture.

[0113] Example 4

[0114] The present invention provides a method for the comprehensive recycling of waste photovoltaic modules, which includes the following steps in the dismantling of waste photovoltaic panels:

[0115] (1) Using automatic dismantling equipment to remove the aluminum frame and junction box of waste photovoltaic panels can not only obtain the complete aluminum frame and junction box, but also prevent them from entering the subsequent sorting steps and reducing sorting efficiency.

[0116] (2) The photovoltaic laminate with the aluminum frame and junction box removed is regularly crushed, with a crushing size of 5cm.

[0117] (3) The crushed laminate was placed in an EVA decomposition reaction device. The reaction temperature was set to 40℃, the pressure to 8MPa, and the processing time to 10min. Under these conditions, the complex decomposed EVA into small molecules, thereby losing its stickiness. After the decomposition reaction, a mixture of glass, plastic backing, solder strip (copper), etc. was obtained.

[0118] (4) Use a color sorter with a sorting accuracy of 0.01mm to sort the mixture and separate the glass. The glass recovery rate can reach 96%, and the remaining material enters the airflow separation stage.

[0119] (5) Use an air classifier to separate the solder strip (copper). After the material enters the air classifier, under the action of wind, the silicon powder and plastic back plate enter the next sorting stage from the light component collector, while the solder strip enters the heavy component collector to complete the sorting process.

[0120] (6) Based on the difference in conductivity, the remaining silicon powder and plastic backing are separated by an electrostatic separator, and the recovery rate of the silicon powder mixture can reach 94%.

[0121] (7) Place the silicon powder mixture in a reactor equipped with a stirrer, add dilute nitric acid solution, and the silver in the mixture dissolves in the dilute nitric acid. Filter the solution and dry the silicon powder precipitate. After drying, the purity of the silicon powder can reach 97%.

[0122] (8) The filtered solution is electrolyzed. During the electrolysis process, the silver nitrate solution is placed in the electrolytic cell, and the anode and cathode are connected to the positive and negative electrodes, respectively. By adding current, the anions are reduced to elemental silver at the cathode, and the silver recovery rate can reach 80%. The electrolyzed solution is then treated a second time to obtain a new dilute nitric acid solution, which is used as a supplementary solution for dissolving the silicon powder mixture.

[0123] Example 5

[0124] The present invention provides a method for the comprehensive recycling of waste photovoltaic modules, which includes the following steps in the dismantling of waste photovoltaic panels:

[0125] (1) Using automatic dismantling equipment to remove the aluminum frame and junction box of waste photovoltaic panels can not only obtain the complete aluminum frame and junction box, but also prevent them from entering the subsequent sorting steps and reducing sorting efficiency.

[0126] (2) The photovoltaic laminate with the aluminum frame and junction box removed is regularly crushed, with a crushing size of 10cm.

[0127] (3) The broken laminate is placed in an EVA decomposition reaction device, the reaction temperature is set to 150℃, the pressure is 8MPa, and the processing time is 60min. Under these conditions, the complex decomposes EVA into small molecules, thereby losing its stickiness. After the decomposition reaction, a mixture of glass, plastic backing, solder strip (copper), etc. is obtained.

[0128] (4) Use a color sorter with a sorting accuracy of 0.01mm to sort the mixture and separate the glass. The glass recovery rate can reach 98%, and the remaining material enters the airflow separation stage.

[0129] (5) Use an air classifier to separate the solder strip (copper). After the material enters the air classifier, under the action of wind, the silicon powder and plastic back plate enter the next sorting stage from the light component collector, while the solder strip enters the heavy component collector to complete the sorting process.

[0130] (6) Based on the difference in conductivity, the remaining silicon powder and plastic backing are separated by an electrostatic separator, and the recovery rate of the silicon powder mixture can reach 96.5%.

[0131] (7) Place the silicon powder mixture in a reactor equipped with a stirrer, add dilute nitric acid solution, the silver in the solution dissolves in the dilute nitric acid, filter the solution, and dry the silicon powder precipitate. After drying, the purity of the silicon powder can reach 98%.

[0132] (8) The filtered solution is electrolyzed. During the electrolysis process, the silver nitrate solution is placed in the electrolytic cell, and the anode and cathode are connected to the positive and negative electrodes, respectively. By adding current, the anions are reduced to elemental silver at the cathode, and the silver recovery rate can reach 86%. The electrolyzed solution is then treated a second time to obtain a new dilute nitric acid solution, which is used as a supplementary solution for dissolving the silicon powder mixture.

[0133] As can be seen from the table below, when the material size is constant, the temperature and time of the decomposition process have a significant impact on the recovery rate of silicon powder, glass and silver. With the increase of temperature and time, the recovery rate increases significantly, but the increase of decomposition process time and temperature will increase the recycling cost. When the crushed size is small, over-crushed glass will be generated during the crushing process, which will reduce the glass recycling efficiency. Therefore, the crushed size should not be too small.

[0134]

[0135] Example 6

[0136] In the method for comprehensive recycling of waste photovoltaic modules according to the present invention, the crusher used includes a roller crusher and a precision crusher connected together. The roller crusher is used to perform preliminary crushing and grinding of the photovoltaic laminate. The crushed material is then transported to the precision crusher for precision crushing. The roller crusher can be a commercially available crusher.

[0137] The structure of the precision crusher is as follows: Figure 3-15 As shown; the precision crusher includes a frame 1, on which a crushing box 2 is connected. A cylindrical filter screen 3 is rotatably connected inside the crushing box 2. The cylindrical filter screen 3 is open on one side near the feed inlet 201 on the side of the crushing box 2, and closed on the other side. A discharge outlet 202 is provided at the bottom of the crushing box 2. A crushing cutter wheel structure 4 is rotatably connected inside the cylindrical filter screen 3. Both ends of the crushing cutter wheel structure 4 are rotatably connected to shaft holes on both sides of the crushing box 2. One end of the crushing cutter wheel structure 4 is connected to an external motor. The other end of the crushing wheel structure 4 is connected to the upper drive wheel structure 5 and the lower drive wheel structure 6. The upper drive wheel structure 5 and the lower drive wheel structure 6 are connected by a filter screen drive structure 7. The upper drive wheel structure 5 is connected to the filter screen cleaning structure 8 mounted on the crushing box 2 to drive the filter screen cleaning structure 8 to clean the cylindrical filter screen 3. The lower drive wheel structure 6 is connected to the screening vibration structure 9 mounted on the crushing box 2 to drive the screening vibration structure 9 to vibrate the cylindrical filter screen 3.

[0138] The precision crusher is used to further crush the photovoltaic laminates after preliminary crushing. During crushing, the photovoltaic laminates after preliminary crushing are fed into the cylindrical filter screen 3 inside the crushing box 2 through the feed inlet 201 on the side of the crushing box 2. One end of the crushing cutter wheel structure 4 is connected to an external motor to drive the crushing cutter wheel structure 4 to rotate, thereby performing fine crushing of the photovoltaic laminates. After crushing, the photovoltaic crushed material that meets the preset fineness requirements passes through the cylindrical filter screen 3 and is discharged through the discharge port 202 at the bottom of the crushing box 2. The open side of the cylindrical filter screen 3 slides on the inner side of the crushing box 2, forming a discharge area between the cylindrical filter screen 3 and the crushing box 2, which facilitates the removal of waste materials. Photovoltaic crushed material is screened out; when the crushing cutter wheel structure 4 is running, it can drive the upper drive wheel structure 5 and the lower drive wheel structure 6 to run synchronously. When the upper drive wheel structure 5 and the lower drive wheel structure 6 are running, they can also drive the cylindrical filter screen 3 to rotate through the filter screen drive structure 7, thereby improving the screening efficiency of the cylindrical filter screen 3 and reducing the probability of clogging of the cylindrical filter screen 3; when the upper drive wheel structure 5 is running, it can also drive the filter screen cleaning structure 8 to run, so as to clean the cylindrical filter screen 3 through the filter screen cleaning structure 8; when the lower drive wheel structure 6 is running, it drives the screening vibration structure 9 mounted on the crushing box 2 to run, so as to drive the screening vibration structure 9 to vibrate the cylindrical filter screen 3 and shake off the material clogging the filter holes of the cylindrical filter screen 3.

[0139] The crushing box 2 includes a lower box 203 fixedly connected to the frame 1, with a discharge port 202 at the bottom of the lower box 203; an upper box 204 is rotatably connected above the lower box 203, with a feed port 201 on the side of the upper box 204, and shaft holes on both sides passing through the middle of the upper box 204 and the lower box 203. The upper box 204 and the lower box 203 of the crushing box 2 can be opened and closed, facilitating the replacement of the cylindrical filter screen 3 or the inspection and maintenance of the cylindrical filter screen 3.

[0140] The crushing blade structure 4 includes a blade shaft 401, which is rotatably connected to the shaft holes on both sides of the crushing box 2, and passes through the central hole of the side plate of the cylindrical filter screen 3. Multiple sets of crushing blades 402 are evenly fixed around the shaft body inside the cylindrical filter screen 3. One end of the blade shaft 401 that extends out of the crushing box 2 is connected to an external motor, and the other end of the blade shaft 401 that extends out of the crushing box 2 is connected to a first bevel gear 403. The first bevel gear 403 is vertically meshed with the upper transmission wheel structure 5 and the lower transmission wheel structure 6.

[0141] The cutter wheel shaft 401 extends to one end of the crushing box 2 and is connected to an external motor. Driven by the external motor, it rotates, thereby driving multiple sets of crushing blades 402 to perform fine crushing of the photovoltaic laminate. When the cutter wheel shaft 401 rotates, it can drive the first bevel gear 403 to rotate, thereby driving the upper transmission wheel structure 5 and the lower transmission wheel structure 6 to operate through the first bevel gear 403.

[0142] The upper transmission wheel structure 5 includes a second bevel gear 501 that meshes perpendicularly with the first bevel gear 403. The second bevel gear 501 and the friction wheel 502 are respectively fixed at the upper and lower ends of the upper transmission shaft 503. The upper transmission shaft 503 is rotatably connected to the frame 1 through the upper bearing bracket 504. The second bevel gear 501 meshes with the filter screen transmission structure 7, and the friction wheel 502 is perpendicularly frictionally connected to the filter screen cleaning structure 8. The filter screen cleaning structure 8 includes a friction disc 801 that is perpendicularly frictionally connected to the friction wheel 502. The friction disc 801 is fixed to one end of the upper horizontal shaft 802. The middle part of the upper horizontal shaft 802 is rotatably connected to the upper housing 204. The other end of the upper horizontal shaft 802 passes into the upper housing 204. The cleaning brush 803 fixed to the upper horizontal shaft 802 is a roller brush that fits on the outer surface of the cylindrical filter screen 3.

[0143] When the first bevel gear 403 rotates, it can mesh with the second bevel gear 501 to rotate, thereby driving the upper transmission shaft 503 and the friction wheel 502 to rotate through the second bevel gear 501. When the friction wheel 502 rotates, the vertical friction transmission friction disk 801 rotates, thereby driving the upper horizontal shaft 802 and the cleaning brush 803 to rotate through the friction disk 801. This facilitates the cleaning of the rotating cylindrical filter screen 3 by the rotating cleaning brush 803, preventing the cylindrical filter screen 3 from becoming clogged.

[0144] The upper drive shaft 503 includes a sliding shaft 8021, on which a friction disc 801 is fixedly connected. The sliding shaft 8021 is slidably connected to a multi-faceted groove at one end of a rotating shaft 8022. A tension spring 8023 is fixedly connected between the sliding shaft 8021 and the inner side of the multi-faceted groove. An adjusting screw 8024 is rotatably connected to the sliding shaft 8021. One end of the adjusting screw 8024, which extends out of the sliding shaft 8021, is fixedly connected to a turning wheel. The other end of the adjusting screw 8024 is screwed... The sliding shaft 8021 is inserted into the internal threaded hole in the multi-faceted slide groove of the rotating shaft 8022 to adjust the length of the sliding shaft 8021 inserted into the multi-faceted slide groove of the rotating shaft 8022; the rotating shaft 8022 is rotatably connected to the upper housing 204, and the cleaning brush 803 is fixed to the rotating shaft 8022; the friction wheel 502 is vertically frictionally connected to the upper side of the friction disk 801, that is, the friction wheel 502 is located above the axis of the friction disk 801, and the friction wheel 502 is stuck above the sliding shaft 8021.

[0145] The friction disc 801 rotates under the drive of the friction wheel 502, thereby driving the sliding shaft 8021 to rotate. The sliding shaft 8021 drives the rotating shaft 8022 and the cleaning brush 803 on the rotating shaft 8022 to rotate. In use, because the friction wheel 502 is positioned above the sliding shaft 8021, the friction wheel 502 not only drives the friction disc 801 to rotate, but also vertically limits the sliding shaft 8021 to prevent it from moving upward. At this time, the upper housing 204 can be locked to prevent it from separating from the lower housing 203. When it is necessary to open the upper housing 204, rotate the adjusting screw 8024 to adjust the relative position of the friction disc 801 and the friction wheel 502. Rotating the adjusting screw 8024 increases the depth to which the adjusting screw 8024 is inserted into the internal threaded hole, thereby increasing the length of the sliding shaft 8021 inserted into the multi-faceted groove of the rotating shaft 8022. At this time, the sliding shaft 8021 drives the friction disc 801 away from the friction wheel 502, which not only stops the transmission action of the friction wheel 502 on the friction disc 801, but also allows the sliding shaft 8021 to disengage from the obstruction limit of the friction wheel 502, making it easier to open the upper housing 204.

[0146] The lower transmission wheel structure 6 includes a third bevel gear 601 that meshes perpendicularly with the first bevel gear 403. The third bevel gear 601 and the worm 602 are respectively fixed at the upper and lower ends of the lower transmission shaft 603. The lower transmission shaft 603 is rotatably connected to the frame 1 through the lower bearing bracket 604. The worm 602 meshes with the screening vibration structure 9, which includes a worm wheel 901. The worm wheel 901 is fixed to one end of the lower horizontal shaft 902. The middle part of the lower horizontal shaft 902 is rotatably connected to the lower housing 203. One end of the lower horizontal shaft 902 inserted into the lower housing 203 is fixedly connected to multiple rotating rings 903. Each of the multiple rotating rings 903 is hinged with a striking head 904 to perform a striking vibration treatment on the cylindrical filter screen 3 through the multiple striking heads 904. The worm 602 meshes with the worm wheel 901.

[0147] When the first bevel gear 403 rotates, it meshes perpendicularly with the third bevel gear 601. The third bevel gear 601 drives the lower transmission shaft 603 and the worm gear 602 to rotate. The worm gear 602 rotates and meshes with the worm wheel 901, thereby driving the lower horizontal shaft 902 to rotate. When the lower horizontal shaft 902 rotates, it drives the striking heads 904 on the multiple rotating rings 903 to swing, thereby using the multiple striking heads 904 to strike and vibrate the cylindrical filter screen 3, shaking off the blockage material on the cylindrical filter screen 3.

[0148] The filter transmission structure 7 includes a fourth bevel gear 701, whose upper and lower ends are perpendicularly meshed with the second bevel gear 501 and the third bevel gear 601, respectively. The fourth bevel gear 701 is fixed to the outer end of the rotating tube 702, which is sleeved on the cutter wheel shaft 401. The middle part of the rotating tube 702 is rotatably connected to a shaft hole on one side of the crushing box 2, and the inner end of the rotating tube 702 is fixed to the cylindrical filter screen 3. When the second bevel gear 501 and the third bevel gear 601 rotate, they perpendicularly mesh with the fourth bevel gear 701, thereby controlling the rotation of the fourth bevel gear 701 and the rotating tube 702. When the rotating tube 702 rotates, it drives the cylindrical filter screen 3 to rotate, performing rotary screening and improving screening efficiency.

[0149] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A method for comprehensive recycling of all components of waste photovoltaic modules, characterized in that, include: The waste photovoltaic panels are disassembled to separate photovoltaic laminates, aluminum frames and junction boxes; The photovoltaic laminate is crushed to obtain photovoltaic crushed material; The process of crushing the photovoltaic laminate includes: placing the photovoltaic laminate in a crusher for crushing and cutting to form photovoltaic crushed material with regular shape and similar or identical size; The photovoltaic fragments are subjected to a decomposition reaction treatment to break down the EVA adhesive in the fragments into non-adhesive molecules; the decomposition reaction treatment of the photovoltaic fragments includes: Photovoltaic crushed material EVA is placed in a decomposition reaction device for EVA decomposition treatment. The temperature of EVA decomposition treatment is 40℃-150℃, the treatment pressure is 8MPa, and the treatment time is 10min-60min. The photovoltaic fragments after the decomposition reaction are sorted to separate glass, plastic backsheet and copper powder, resulting in a silicon powder mixture. The silicon powder mixture is dissolved to obtain a silver-containing solution and silicon powder precipitate. After separating the silicon powder precipitate, the silver-containing solution is converted into elemental silver for recovery. The crushers used include a roller crusher and a precision crusher connected together. The roller crusher is used to perform preliminary crushing of the photovoltaic laminates. The preliminary crushing process then transports the crushed material to the precision crusher for further crushing. The precision crusher includes a frame with a crushing box connected to it. A cylindrical filter screen is rotatably connected inside the crushing box. The cylindrical filter screen is open on one side near the feed inlet and closed on the other side. A discharge outlet is located at the bottom of the crushing box. A crushing cutter wheel structure is rotatably connected inside the cylindrical filter screen. Both ends of the crushing cutter wheel structure are rotatably connected to shaft holes on both sides of the crushing box. One end of the crushing cutter wheel structure is connected to an external motor, and the other end is connected to an upper drive wheel structure and a lower drive wheel structure. The upper and lower drive wheel structures are connected via a filter screen transmission structure. A filter screen cleaning structure mounted on the crushing box is connected above the upper drive wheel structure to clean the cylindrical filter screen. A screening vibration structure mounted on the crushing box is connected below the lower drive wheel structure. When the upper and lower drive wheel structures are in operation, they can also drive the cylindrical filter screen to rotate through the filter screen drive structure. The crushing box includes a lower box body fixedly connected to the frame, with a discharge port at the bottom of the lower box body; an upper box body is rotatably connected to the upper box body, with a feed port on the side of the upper box body, and shaft holes on both sides passing through the middle of the upper box body and the lower box body; the upper box body and the lower box body of the crushing box can be opened and closed. The crushing wheel structure includes a crushing wheel shaft, which is rotatably connected to the shaft holes on both sides of the crushing box, and the crushing wheel shaft passes through the central hole of the cylindrical filter screen side plate; multiple sets of crushing blades are evenly fixed around the shaft body inside the cylindrical filter screen; the crushing wheel shaft extends to the other end of the crushing box and is connected to the first bevel gear, which is vertically meshed with the upper transmission wheel structure and the lower transmission wheel structure; The upper drive wheel structure includes a second bevel gear that meshes perpendicularly with the first bevel gear. The second bevel gear and the friction wheel are respectively fixed at the upper and lower ends of the upper drive shaft. The upper drive shaft is rotatably connected to the frame through the upper bearing bracket. The second bevel gear meshes with the filter screen drive structure, and the friction wheel is perpendicularly frictionally connected to the filter screen cleaning structure. The filter screen cleaning structure includes a friction disc that is perpendicularly frictionally connected to the friction wheel. The friction disc is fixed to one end of the upper horizontal shaft. The middle part of the upper horizontal shaft is rotatably connected to the upper housing. The other end of the upper horizontal shaft passes into the upper housing. A cleaning brush roller fixed to the upper horizontal shaft is fitted onto the outer surface of the cylindrical filter screen. The upper drive shaft includes a sliding shaft body, a friction disc fixedly connected to the sliding shaft body, and the sliding shaft body slidably connected to a multi-faceted groove at one end of the rotating shaft body. A tension spring is fixedly connected between the sliding shaft body and the inner side of the multi-faceted groove. An adjusting screw is rotatably connected to the sliding shaft body. One end of the adjusting screw, which extends to the outside of the sliding shaft body, is fixedly connected to a turning wheel. The other end of the adjusting screw is threaded into an internal threaded hole in the multi-faceted groove of the rotating shaft body to adjust the length of the sliding shaft body inserted into the multi-faceted groove of the rotating shaft body. The rotating shaft body is rotatably connected to the upper housing, and a cleaning brush is fixedly connected to the rotating shaft body. A friction wheel is vertically frictionally connected above the side of the friction disc. The friction wheel is blocked above the sliding shaft body. The sieve vibration structure includes a worm gear, which is fixed to one end of the lower horizontal shaft. The middle of the lower horizontal shaft is rotatably connected to the lower housing. One end of the lower horizontal shaft, which is inserted into the lower housing, is fixedly connected to multiple rotating rings. Each of the multiple rotating rings is hinged with a striking head.

2. The method for comprehensive recycling of waste photovoltaic modules according to claim 1, characterized in that, The size range of the photovoltaic crushed material is 2cm-10cm.

3. The method for comprehensive recycling of waste photovoltaic modules according to claim 1, characterized in that, The process of sorting the photovoltaic crushed material after decomposition reaction includes: Glass is separated from photovoltaic rubble using a color sorter. Copper powder is separated from photovoltaic crushed material by airflow separator. The plastic backsheet in the photovoltaic crushed material is separated by an electrostatic separator. After separating the glass, copper powder, and plastic backing, a mixture of silicon powder is obtained.

4. The method for comprehensive recycling of waste photovoltaic modules according to claim 1, characterized in that, When sorting by color sorter, the sorting accuracy is 0.01mm.

5. The method for comprehensive recycling of waste photovoltaic modules according to claim 1, characterized in that, The process of dissolving the silicon powder mixture includes: The silicon powder mixture was put into a reaction vessel, and a dilute nitric acid solution was added as a dissolving agent to carry out the dissolution reaction. The silicon powder precipitate was obtained by filtration.

6. The method for comprehensive recycling of waste photovoltaic modules according to claim 5, characterized in that, When dilute nitric acid solution is added as a dissolving agent for the dissolution reaction, the dissolving agent and the silicon powder mixture are stirred by a stirring device inside the reaction vessel.

7. The method for comprehensive recycling of waste photovoltaic modules according to claim 1, characterized in that, After the separated silicon powder precipitates, the separated silicon powder is placed in a drying device for drying treatment.

8. The method for comprehensive recycling of waste photovoltaic modules according to claim 1, characterized in that, The process of converting the silver-containing solution into elemental silver for recovery includes: The silver-containing solution is placed in an electrolytic cell, and an electric current is applied to reduce the silver ions in the silver-containing solution to elemental silver.

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