Method and equipment for recovering silver from crystalline silicon photovoltaic module

Abstract

The invention belongs to the technical field of silver recovery methods, and particularly relates to a method and equipment for recovering silver in a crystalline silicon photovoltaic module, and the equipment comprises a box body, a conveying device, a visual sensor, a moving device, a distance measuring sensor, a surface cleaning device, a cosolvent adding device, a laser transmitter, a compressed air extraction device and a harmful waste gas extraction device; comprising the following steps of (1) battery piece separation, (2) silver recovery through a laser melting silver recovery device, and (3) metal separation and purification. The laser melting silver recovery equipment has the beneficial effects that through the visual sensor, the moving device and the distance measuring sensor, the laser transmitter can accurately melt silver wires, the melting temperature of the silver powder is reduced through the cosolvent, meanwhile, the compressed air extraction device is used for accurately collecting silver, and therefore the precision and efficiency of silver recovery are improved, and the production cost is reduced. And the purity of the recovered silver is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of methods for recovering silver, and in particular relates to a method and equipment for recovering silver from a crystalline silicon photovoltaic module. Background Art

[0002] Silver is a precious metal with good conductivity and is widely used in the manufacture of photovoltaic cells. However, discarded photovoltaic cells generate a huge amount of electronic waste. Efficiently recycling silver from waste photovoltaic panels can not only reduce environmental pressure and achieve a circular economy, but also help reduce the production cost of new photovoltaic products. At the same time, it can solve the problem of resource shortage and reduce the exploitation of silver mine resources.

[0003] The existing method of recovering silver from crystalline silicon photovoltaic modules is to mechanically crush the cells and then recover the silver materials through chemical leaching and hot melting. The recovered silver has low purity and is difficult to handle the complex composite materials after mechanical crushing. It also increases the discharge of wastewater containing hazardous chemicals and increases air pollution. Therefore, how to improve the purity of silver recovered from crystalline silicon photovoltaic modules and how to reduce the harm to the environment when recovering silver from crystalline silicon photovoltaic modules have become urgent problems to be solved. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problem and provide a method and a recycling device for recovering silver from a crystalline silicon photovoltaic module.

[0005] The present invention relates to a laser molten silver recovery device, comprising a box, a conveying device, a visual sensor, a moving device, a distance sensor, a surface cleaning device, a co-solvent adding device, a laser transmitter, a compressed air extraction device and a harmful waste gas extraction device; A battery inlet and a battery outlet are respectively provided on both sides of the box body, the conveying device is fixedly connected to the bottom of the box body between the battery inlet and the battery outlet, the visual sensor is fixedly connected to the top of the box body on one side close to the battery inlet, the harmful exhaust gas extraction device is fixedly connected to the top of the box body on one side close to the battery outlet, the moving device is fixedly connected to the top of the box body between the visual sensor and the harmful exhaust gas extraction device, the ranging sensor, the surface cleaning device and the co-solvent adding device are all fixedly connected to the side of the lower part of the moving device close to the visual sensor, and the laser emitter and the compressed air extraction device are all fixedly connected to the side of the lower part of the moving device close to the harmful exhaust gas extraction device.

[0006] Preferably, the moving device comprises a screw frame 1, a screw frame 2, a screw 1, a screw 2, a screw 3, a motor 1, a motor 2 and a motor 3; The screw rod frame 1 is fixedly connected to the top of the box body between the visual sensor and the harmful exhaust gas extraction device, the screw rod 1 is rotatably connected to the screw rod frame 1, the motor 1 is fixedly connected to the outer side of the screw rod frame 1, and the motor 1 drives the screw rod 1 to rotate; the screw rod frame 2 is threadedly connected to the bottom of the screw rod 1, the screw rod 2 is rotatably connected to a side of the screw rod frame 2 close to the visual sensor, the motor 2 is fixedly connected to a side of the screw rod frame 2 close to the visual sensor, and the motor 2 drives the screw rod 2 to rotate; the screw rod 3 is rotatably connected to a side of the screw rod frame 2 away from the visual sensor, the motor 3 is fixedly connected to a side of the screw rod frame 2 away from the visual sensor, and the motor 3 drives the screw rod 3 to rotate; The axial direction of the screw rod 1 is perpendicular to that of the screw rod 2, the axial direction of the screw rod 2 is the same as the conveying direction of the conveying device, and the axial direction of the screw rod 2 is the same as that of the screw rod 3.

[0007] Preferably, a connecting component 1 is threadedly connected below the screw rod 2, the distance measuring sensor is fixedly connected to a side of the connecting component 1 below close to the visual sensor, a linear telescopic device 1 is fixedly connected to a side of the connecting component 1 below away from the visual sensor, a side of the linear telescopic device 1 below close to the distance measuring sensor is fixedly connected to the surface cleaning device, and a side of the linear telescopic device 1 below away from the distance measuring sensor is fixedly connected to the co-solvent adding device.

[0008] Preferably, a linear telescopic device 2 is threadedly connected below the screw rod 3, a side of the linear telescopic device 2 below close to the co-solvent adding device is fixedly connected to the laser emitter, and a side of the linear telescopic device 2 below away from the co-solvent adding device is fixedly connected to the compressed air extraction device.

[0009] Preferably, the visual sensor, the conveying device, the distance measuring sensor, the motor 1, the motor 2, the motor 3, the linear telescopic device 1 and the linear telescopic device 2 are all externally connected to a PLC controller.

[0010] The present invention also relates to a method for recovering silver from a crystalline silicon photovoltaic module, which uses the laser melting silver recovery device to recover silver, comprising the following steps: 1) Cell separation Disassemble the crystalline silicon photovoltaic module, remove the wire box and frame to obtain a laminate; after heating the laminate, peel off and remove the backboard material; then heat the laminate without the backboard, and separate the glass and the packaging film with a hot knife; place the packaging film containing the battery cell in a pyrolysis furnace, heat it under an inert atmosphere, and perform pyrolysis to decompose the packaging film to obtain the battery cell; perform ultrasonic cleaning on the battery cell to remove impurities attached to the surface and then dry it; 2) Laser melting recovery The laser-melted silver recovery device melts the silver wire on the battery cell and collects the silver material; 3) Metal separation and purification The extracted silver material is washed with purified water, and solid-liquid separation is performed by centrifugation to obtain crude silver; the crude silver is dissolved with a low-concentration nitric acid solution to separate insoluble impurities, and then a sodium chloride solution is added to the silver-containing solution to precipitate the silver ions in the form of silver chloride. The precipitated silver chloride is filtered and washed, and then slurried with purified water. After adding ammonia water to dissolve the silver chloride, hydrazine hydrate is slowly added for reduction to obtain sponge silver. The sponge silver is placed in a crucible and smelted in a high-frequency induction furnace to obtain a silver ingot.

[0011] Preferably, in step 2), the battery cell is placed on the conveying device from the battery inlet; the conveying device drives the battery cell to pass through the visual sensor, and the visual sensor sends the position of the silver line area on the battery cell to the PLC controller. After the PLC controller processes the data, it issues a command to the motor 1, and the motor 1 drives the screw rod 1 to rotate, thereby driving the screw rod frame 2 to move back and forth until the distance sensor and the silver line area are in the same straight line. When the battery cell passes through the distance sensor, the distance sensor sends data to the PLC controller. After the PLC controller processes the data, it issues a command to the linear telescopic device 1 and the linear telescopic device 2. The first linear telescopic device drives the surface cleaning device and the solvent adding device to the silver wire area of ​​the battery cell. When the conveying device drives the battery cell through the surface cleaning device and the solvent adding device, the surface cleaning device removes surface impurities in the silver wire area of ​​the battery cell, and the solvent adding device applies a saturated solution of the solvent to the silver wire area of ​​the battery cell. Then, the second linear telescopic device drives the laser emitter and the compressed air extraction device to the silver wire area of ​​the battery cell. When the conveying device drives the battery cell through the laser emitter and the compressed air extraction device, the laser emitter irradiates the silver wire area, and the silver wire melts into a ball. The compressed air extraction device extracts and collects the molten silver.

[0012] Preferably, in step 2), the co-solvent includes at least one of sodium chloride, boric acid and phosphoric acid.

[0013] Preferably, in step 1), the laminate is heated to 80°C to 90°C; the laminate without backboard is heated to 80°C to 85°C; the temperature of the hot knife is 90°C to 95°C; the laminate is heated to 580°C to 650°C under an inert atmosphere and pyrolyzed for 40min to 60min.

[0014] Preferably, in step 3), the pH value of the reaction solution is controlled by ammonia water to be 10-11.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are: Compared with the prior art, the method and equipment for recovering silver from crystalline silicon photovoltaic modules of the present invention are (1) The laser melting silver recovery equipment uses visual sensors, mobile devices and distance sensors to enable the laser transmitter to accurately melt the silver wire of the crystalline silicon photovoltaic module, and uses a solvent to reduce the melting temperature of the silver powder to promote agglomeration. At the same time, a compressed air extraction device is used to accurately collect the silver material, thereby improving the accuracy and efficiency of silver recovery and improving the purity of the recovered silver; (2) The method of recovering silver from crystalline silicon photovoltaic modules utilizes the instantaneous high temperature generated by laser to melt the silver wire. Compared with the chemical leaching method and the hot melt method, it does not require physical crushing of the cell and will not cause secondary damage to the cell panel, which is conducive to the next step of recycling and sorting of the cell. Compared with the hot melt method, it reduces air pollution and compared with the chemical leaching method, it reduces the discharge of wastewater containing hazardous chemicals. (3) The method for recovering silver from crystalline silicon photovoltaic modules has high purity, which greatly reduces the cost and difficulty of purifying the recovered silver, thereby reducing the secondary loss of the recovered silver. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following briefly introduces the drawings required for describing the embodiment. Figure 1 A schematic diagram of a laser-melted silver recovery device provided in Example 1; Figure 2 A front view of a laser molten silver recovery device provided in Example 1; Figure 3 A cross-sectional view of the laser-melted silver recovery equipment provided in Example 1.

[0017] Description of reference numerals: 1—box, 2—transmission device, 3—visual sensor, 4—moving device, 5—distance measuring sensor, 6—surface cleaning device, 7—solvent adding device, 8—laser emitter, 9—compressed air extraction device, 10—harmful exhaust gas extraction device, 11—battery inlet, 12—battery outlet, 13—screw frame one, 14—screw frame two; 15—screw one, 16—screw two, 17—screw three, 18—motor one, 19—motor two, 20—motor three, 21—connecting assembly, 22—linear telescopic device one, 23—linear telescopic device two. DETAILED DESCRIPTION

[0018] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described below with reference to the accompanying drawings and embodiments.

[0019] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0020] Example 1 like Figure 1-Figure 3 A laser molten silver recovery device shown includes a housing 1, a conveying device 2, a visual sensor 3, a moving device 4, a distance sensor 5, a surface cleaning device 6, a co-solvent adding device 7, a laser transmitter 8, a compressed air extraction device 9 and a harmful waste gas extraction device 10; like Figure 1-Figure 3 As shown, a battery inlet 11 and a battery outlet 12 are respectively provided on both sides of the box body 1, the conveying device 2 is fixedly connected to the bottom of the box body 1 between the battery inlet 11 and the battery outlet 12, the visual sensor 3 is fixedly connected to the top of the box body 1 on one side close to the battery inlet 11, the harmful exhaust gas extraction device 10 is fixedly connected to the top of the box body 1 on one side close to the battery outlet 12, the moving device 4 is fixedly connected to the top of the box body 1 between the visual sensor 3 and the harmful exhaust gas extraction device 10, the ranging sensor 5, the surface cleaning device 6 and the co-solvent adding device 7 are all fixedly connected to the side of the lower part of the moving device 4 close to the visual sensor 3, and the laser emitter 8 and the compressed air extraction device 9 are all fixedly connected to the side of the lower part of the moving device 4 close to the harmful exhaust gas extraction device 10.

[0021] like Figure 1-Figure 3 As shown, the moving device 4 includes a screw frame 1 13, a screw frame 2 14, a screw 1 15, a screw 2 16, a screw 3 17, a motor 1 18, a motor 2 19 and a motor 3 20; like Figure 1-Figure 3 As shown, the screw frame 13 is fixedly connected to the top of the box body 1 between the visual sensor 3 and the harmful exhaust gas extraction device 10, the screw 15 is rotatably connected to the screw frame 13, the motor 18 is fixedly connected to the outside of the screw frame 13, and the motor 18 drives the screw 15 to rotate; the screw frame 2 14 is threadedly connected to the bottom of the screw 15, the screw 2 16 is rotatably connected to the side of the screw frame 2 14 close to the visual sensor 3, the motor 2 19 is fixedly connected to the side of the screw frame 2 14 close to the visual sensor 3, and the motor 2 19 drives the screw 2 16 to rotate; the screw 3 17 is rotatably connected to the side of the screw frame 2 14 away from the visual sensor 3, the motor 3 20 is fixedly connected to the side of the screw frame 2 14 away from the visual sensor 3, and the motor 3 20 drives the screw 3 17 to rotate; like Figure 1-Figure 3 As shown, the axial directions of screw rod 1 15 and screw rod 2 16 are perpendicular, the axial direction of screw rod 2 16 is the same as the conveying direction of the conveying device 2 , and the axial directions of screw rod 2 16 and screw rod 3 17 are the same.

[0022] like Figure 1-Figure 3 As shown, a connecting component 21 is threadedly connected below the screw rod 16, the distance sensor 5 is fixedly connected to the side of the connecting component 21 below the visual sensor 3, a linear telescopic device 22 is fixedly connected to the side of the connecting component 21 below the visual sensor 3, the side of the linear telescopic device 22 below the distance sensor 5 is fixedly connected to the surface cleaning device 6, and the side of the linear telescopic device 22 below the distance sensor 5 is fixedly connected to the co-solvent adding device 7.

[0023] like Figure 1-Figure 3 As shown, a linear telescopic device 23 is threadedly connected below the screw rod 3 17, and the side of the linear telescopic device 23 below the solvent adding device 7 is fixedly connected to the laser emitter 8, and the side of the linear telescopic device 23 below the solvent adding device 7 is fixedly connected to the compressed air extraction device 9.

[0024] like Figure 1-Figure 3 As shown, the visual sensor 3, the conveying device 2, the distance measuring sensor 5, the motor 1 18, the motor 2 19, the motor 3 20, the linear telescopic device 1 22 and the linear telescopic device 2 23 are all externally connected to the PLC controller.

[0025] A method for recovering silver from a crystalline silicon photovoltaic module, using the above-mentioned laser melting silver recovery device to recover silver, comprises the following steps: 1) Cell separation Disassemble the crystalline silicon photovoltaic module, remove the wire box and frame to obtain a laminate; after heating the laminate, peel off and remove the backboard material; then heat the laminate without the backboard, and separate the glass and the packaging film with a hot knife; place the packaging film containing the battery cell in a pyrolysis furnace, heat it under an inert atmosphere, and perform pyrolysis to decompose the packaging film to obtain the battery cell; perform ultrasonic cleaning on the battery cell to remove impurities attached to the surface and then dry it; 2) Laser melting recovery Laser-melted silver recovery equipment melts the silver wires on the cell and collects the silver material; 3) Metal separation and purification The extracted silver material is washed with purified water, and solid-liquid separation is performed by centrifugation to obtain crude silver; the crude silver is dissolved with a low-concentration nitric acid solution to separate insoluble impurities, and then a sodium chloride solution is added to the silver-containing solution to precipitate the silver ions in the form of silver chloride. The precipitated silver chloride is filtered and washed, and then slurried with purified water. After ammonia water is added to dissolve the silver chloride, hydrazine hydrate is slowly added for reduction to obtain sponge silver. The sponge silver is placed in a crucible and smelted in a high-frequency induction furnace to obtain a silver ingot.

[0026] In step 2), the battery cell is placed on the conveying device 2 from the battery inlet 11; the conveying device 2 drives the battery cell to pass through the visual sensor 3, and the visual sensor 3 sends the position of the silver line area on the battery cell to the PLC controller. After the PLC controller processes the data, it issues a command to the motor 18, and the motor 18 drives the screw rod 15 to rotate, thereby driving the screw rod frame 2 14 to move back and forth until the distance sensor 5 and the silver line area are in the same straight line. When the battery cell passes through the distance sensor 5, the distance sensor 5 sends data to the PLC controller. After the PLC controller processes the data, it issues a command to the linear telescopic device 1 22 and the linear telescopic device 2 23. The first device 22 drives the surface cleaning device 6 and the solvent adding device 7 to the silver wire area of ​​the battery cell. When the conveying device drives the battery cell through the surface cleaning device 6 and the solvent adding device 7, the surface cleaning device 6 removes surface impurities in the silver wire area of ​​the battery cell, and the solvent adding device 7 applies a saturated solution of the solvent to the silver wire area of ​​the battery cell. Then the linear telescopic device 23 drives the laser emitter 8 and the compressed air extraction device 9 to the silver wire area of ​​the battery cell. When the conveying device drives the battery cell through the laser emitter 8 and the compressed air extraction device 9, the laser emitter 8 irradiates the silver wire area, and the silver wire melts into a ball, and the compressed air extraction device 9 extracts and collects the molten silver.

[0027] In step 2), the cosolvent is sodium chloride.

[0028] In step 1), the laminate is heated to 90°C; the laminate without backing plate is heated to 80°C; the temperature of the hot knife is 90°C; the laminate is heated to 580°C under an inert atmosphere and pyrolyzed for 60 minutes.

[0029] In step 3), the pH value of the reaction solution is controlled to be 10 by using ammonia water.

[0030] Example 2 The difference between this embodiment and embodiment 1 is that: In step 2), the cosolvent is boric acid.

[0031] In step 1), the laminate is heated to 80°C; the laminate without backing plate is heated to 85°C; the temperature of the hot knife is 95°C; the laminate is heated to 650°C under an inert atmosphere and pyrolyzed for 40 minutes.

[0032] In step 3), the pH value of the reaction solution is controlled to be 11 by aqueous ammonia.

[0033] Comparative Example 1 The difference between this embodiment and embodiment 1 is that: In step 2), no solvent is added during laser melting to recover silver.

[0034] Comparative Example 2 The difference between this embodiment and embodiment 1 is that: (2) Mechanical crushing The disassembled battery cells are crushed using a rotor crusher and a hammer crusher, and then the silver metal powder and the mixed powder containing silver metal are screened by electromagnetic separation.

[0035] (3) Chemical leaching The silver metal was dissolved using nitric acid and separated from the glass by filtration.

[0036] Comparative Example 3 The difference between this embodiment and embodiment 1 is that: (2) Mechanical crushing The disassembled battery cells are crushed using a rotor crusher and a hammer crusher, and then the silver metal powder and the mixed powder containing silver metal are screened by electromagnetic separation.

[0037] (3) Melting and separation The silver metal powder and the mixed powder containing silver metal are melted at high temperature, the silver metal is separated from the mixture to form liquid metal, and then the liquid silver metal is separated from the solid impurities by the pouring method.

[0038] Performance Testing The ratio of the weight of silver actually recovered from the battery cells of Examples 1-2 and Comparative Examples 1-3 to the weight of silver in the theoretical battery cells was calculated, and the results are shown in Table 1.

[0039] Table 1 It can be seen from Table 1 that compared with comparative examples 1-3, the silver recovery ratio of Examples 1-2 is higher, excluding the losses caused by the peeling and falling of the silver wire during the use and disassembly of the crystalline silicon module, it is close to the silver recovery limit, indicating that the method for recovering silver in crystalline silicon photovoltaic modules has a high silver recovery ratio.

[0040] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes for application in other fields. However, any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A laser molten silver recovery device, characterized in that: It comprises a box (1), a conveying device (2), a visual sensor (3), a moving device (4), a distance sensor (5), a surface cleaning device (6), a solvent adding device (7), a laser transmitter (8), a compressed air extraction device (9) and a harmful waste gas extraction device (10); The box (1) is provided with a battery inlet (11) and a battery outlet (12) on both sides, the conveying device (2) is fixedly connected to the bottom of the box (1) between the battery inlet (11) and the battery outlet (12), the visual sensor (3) is fixedly connected to the top of the box (1) on one side close to the battery inlet (11), the harmful exhaust gas extraction device (10) is fixedly connected to the top of the box (1) on one side close to the battery outlet (12), the moving device (4) is fixedly connected to the top of the box (1) between the visual sensor (3) and the harmful exhaust gas extraction device (10), the distance measuring sensor (5), the surface cleaning device (6) and the co-solvent adding device (7) are all fixedly connected to the side of the moving device (4) below the visual sensor (3), and the laser emitter (8) and the compressed air extraction device (9) are all fixedly connected to the side of the moving device (4) below the harmful exhaust gas extraction device (10).

2. The laser molten silver recovery equipment according to claim 1, characterized in that: The moving device (4) comprises a screw frame 1 (13), a screw frame 2 (14), a screw 1 (15), a screw 2 (16), a screw 3 (17), a motor 1 (18), a motor 2 (19) and a motor 3 (20); The screw rod frame 1 (13) is fixedly connected to the top of the box body (1) between the visual sensor (3) and the harmful exhaust gas extraction device (10); the screw rod 1 (15) is rotatably connected to the inside of the screw rod frame 1 (13); the motor 1 (18) is fixedly connected to the outside of the screw rod frame 1 (13); the motor 1 (18) drives the screw rod 1 (15) to rotate; the screw rod frame 2 (14) is threadedly connected to the bottom of the screw rod 1 (15); the screw rod 2 (16) is rotatably connected to the inside of the screw rod frame 2 (14) near the screw rod. The second motor (19) is fixedly connected to a side of the second screw frame (14) close to the visual sensor (3), and the second motor (19) drives the second screw (16) to rotate; the third screw (17) is rotationally connected to a side of the second screw frame (14) away from the visual sensor (3), and the third motor (20) is fixedly connected to a side of the second screw frame (14) away from the visual sensor (3), and the third motor (20) drives the third screw (17) to rotate; The axial direction of the screw rod 1 (15) is perpendicular to the axial direction of the screw rod 2 (16), the axial direction of the screw rod 2 (16) is the same as the conveying direction of the conveying device (2), and the axial direction of the screw rod 2 (16) is the same as the axial direction of the screw rod 3 (17).

3. The laser molten silver recovery equipment according to claim 2, characterized in that: A connecting component (21) is threadedly connected below the second screw rod (16); the distance sensor (5) is fixedly connected to a side of the connecting component (21) below the visual sensor (3); a linear telescopic device (22) is fixedly connected to a side of the connecting component (21) below the visual sensor (3); a side of the linear telescopic device (22) below the distance sensor (5) is fixedly connected to the surface cleaning device (6); and a side of the linear telescopic device (22) below the distance sensor (5) is fixedly connected to the co-solvent adding device (7).

4. The laser molten silver recovery equipment according to claim 3, characterized in that: A linear telescopic device 2 (23) is threadedly connected below the screw rod 3 (17); a side of the linear telescopic device 2 (23) below the co-solvent adding device (7) is fixedly connected to the laser emitter (8); and a side of the linear telescopic device 2 (23) below the co-solvent adding device (7) is fixedly connected to the compressed air extraction device (9).

5. The laser molten silver recovery equipment according to claim 4, characterized in that: The visual sensor (3), the conveying device (2), the distance measuring sensor (5), the motor 1 (18), the motor 2 (19), the motor 3 (20), the linear telescopic device 1 (22) and the linear telescopic device 2 (23) are all externally connected to a PLC controller.

6. A method for recovering silver from a crystalline silicon photovoltaic module, characterized in that: Silver recovery using the laser molten silver recovery device according to any one of claims 1 to 5 comprises the following steps: 1) Cell separation Disassemble the crystalline silicon photovoltaic module, remove the wire box and frame to obtain a laminate; after heating the laminate, peel off and remove the backboard material; then heat the laminate without the backboard, and separate the glass and the packaging film with a hot knife; place the packaging film containing the battery cell in a pyrolysis furnace, heat it under an inert atmosphere, and perform pyrolysis to decompose the packaging film to obtain the battery cell; perform ultrasonic cleaning on the battery cell to remove impurities attached to the surface and then dry it; 2) Laser melting recovery The laser-melted silver recovery device melts the silver wire on the battery cell and collects the silver material; 3) Metal separation and purification The extracted silver material is washed with purified water, and solid-liquid separation is performed by centrifugation to obtain crude silver; the crude silver is dissolved with a low-concentration nitric acid solution to separate insoluble impurities, and then a sodium chloride solution is added to the silver-containing solution to precipitate the silver ions in the form of silver chloride. The precipitated silver chloride is filtered and washed, and then slurried with purified water. After adding ammonia water to dissolve the silver chloride, hydrazine hydrate is slowly added for reduction to obtain sponge silver. The sponge silver is placed in a crucible and smelted in a high-frequency induction furnace to obtain a silver ingot.

7. The method for recovering silver from crystalline silicon photovoltaic modules according to claim 6, characterized in that: In the step 2), the battery cell is placed on the conveying device (2) from the battery inlet (11); the conveying device (2) drives the battery cell to pass through the visual sensor (3); the visual sensor (3) sends the position of the silver line area on the battery cell to the PLC controller; the PLC controller processes the data and issues a command to the motor 1 (18); the motor 1 (18) drives the screw rod 1 (15) to rotate, thereby driving the screw rod frame 2 (14) to move forward and backward until the distance sensor (5) and the silver line area are in the same straight line; when the battery cell passes through the distance sensor (5), the distance sensor (5) sends data to the PLC controller; the PLC controller processes the data and issues a command to the linear telescopic device 1 (22) and the linear telescopic device 2 (23); The first linear telescopic device (22) drives the surface cleaning device (6) and the solvent adding device (7) to contact the silver wire area of ​​the battery cell. When the conveying device drives the battery cell to pass through the surface cleaning device (6) and the solvent adding device (7), the surface cleaning device (6) removes surface impurities in the silver wire area of ​​the battery cell, and the solvent adding device (7) applies a saturated solution of the solvent to the silver wire area of ​​the battery cell. Then, the second linear telescopic device (23) drives the laser emitter (8) and the compressed air extraction device (9) to contact the silver wire area of ​​the battery cell. When the conveying device drives the battery cell to pass through the laser emitter (8) and the compressed air extraction device (9), the laser emitter (8) irradiates the silver wire area, and the silver wire melts into a ball. The compressed air extraction device (9) extracts and collects the molten silver.

8. The method for recovering silver from crystalline silicon photovoltaic modules according to claim 7, characterized in that: In the step 2), the co-solvent includes at least one of sodium chloride, boric acid and phosphoric acid.

9. The method for recovering silver from crystalline silicon photovoltaic modules according to claim 8, characterized in that: In the step 1), the laminate is heated to 80°C to 90°C; the laminate without backboard is heated to 80°C to 85°C; the temperature of the hot knife is 90°C to 95°C; the laminate is heated to 580°C to 650°C under an inert atmosphere and pyrolyzed for 40min to 60min.

10. The method for recovering silver from crystalline silicon photovoltaic modules according to claim 9, characterized in that: In the step 3), the pH value of the reaction solution is controlled by ammonia water to be 10-11.

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