Recovery method and recovery device for metal in photovoltaic module solder strip

Abstract

The invention relates to the technical field of photovoltaic module resource recovery, in particular to a method and device for recovering metal in a photovoltaic module welding strip. The recovery method provided by the invention comprises the following steps: splitting a waste photovoltaic module to obtain a photovoltaic module solder strip; carrying out acid leaching treatment on the photovoltaic module welding strip by adopting a nitric acid solution to prepare copper-rich leaching residues and a first solution; a first alkaline solution is added into the first solution, the pH value of the first solution is made to be 1-2, and a tin-rich solid and a second solution are prepared; a second alkaline solution is added into the second solution, so that the pH value of the second solution is 5-6.5, and a copper-rich solid and a third solution are prepared; a third alkaline solution is added into the third solution, the pH value of the third solution is made to be 8-10, and a lead-rich solid and a fourth solution are prepared; wherein the mass concentration of the nitric acid solution is 5%-10%. According to the recycling method, tin, copper and lead can be effectively separated and recycled, and recycling of resources is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic module resource recovery, and in particular to a method and device for recovering metals in photovoltaic module welding strips. Background Art

[0002] Photovoltaic modules, as a clean and renewable energy source, have developed rapidly in recent years. The life cycle of photovoltaic modules is about 25 to 30 years, and the disposal of photovoltaic modules after their life cycle has become an inevitable problem. If photovoltaic modules after their life cycle are simply crushed, buried or incinerated, it will not only pollute the environment, but also be a waste of resources. Therefore, recycling photovoltaic module materials after their life cycle can not only achieve resource reuse, but also effectively protect the environment.

[0003] Photovoltaic modules are mainly composed of cells, backplanes, glass, photovoltaic ribbons, frames and silicone. The photovoltaic ribbons are tin-coated copper ribbons, which are mainly composed of a copper matrix and a tin coating layer. To improve the welding performance and corrosion resistance of the tin-coated copper ribbons, the tin coating layer usually also includes silver and lead. At present, the relevant recycling methods only roughly recycle silver, but the copper, tin and lead in the photovoltaic ribbons are not separated and recycled in detail. Summary of the invention

[0004] Based on this, it is necessary to provide a method and device for recycling metals in photovoltaic module welding strips to address the problem of copper, tin and lead not being separated and recycled in detail.

[0005] In a first aspect of the present application, a method for recovering metal from a photovoltaic module welding ribbon is provided, comprising the following steps:

[0006] Disassemble and process the waste photovoltaic modules to obtain the photovoltaic module welding strips;

[0007] The photovoltaic module welding strip is subjected to acid leaching treatment using a nitric acid solution to prepare copper-rich leaching residue and a first solution;

[0008] Adding a first alkaline solution to the first solution to adjust the pH value of the first solution to 1-2, thereby preparing a tin-rich solid and a second solution;

[0009] Adding a second alkaline solution to the second solution to adjust the pH value of the second solution to 5-6.5, to prepare a copper-rich solid and a third solution;

[0010] Adding a third alkaline solution to the third solution to adjust the pH value of the third solution to 8-10, thereby preparing a lead-rich solid and a fourth solution;

[0011] Wherein, the mass concentration of the nitric acid solution is 5%~10%.

[0012] In one embodiment, the recovery method has one or more of the following characteristics:

[0013] (1) The mass concentration of the first alkaline solution is 5% to 10%;

[0014] (2) The mass concentration of the second alkaline solution is 5% to 10%;

[0015] (3) The mass concentration of the third alkaline solution is 5% to 10%.

[0016] In one embodiment, the first alkaline solution, the second alkaline solution and the third alkaline solution are each independently selected from one or more of a NaOH solution and a KOH solution.

[0017] In one embodiment, the process parameters of the acid leaching treatment have one or more of the following characteristics:

[0018] (1) The acid leaching temperature is 15°C to 35°C,

[0019] (2) The acid leaching treatment time is 1h~4h;

[0020] (3) Applying an ultrasonic power of 400 W to 600 W during the acid leaching treatment.

[0021] In one embodiment, the recovery method further comprises the step of treating the fourth solution, specifically comprising:

[0022] A chloride ion solution is added to the fourth solution to prepare silver chloride solid.

[0023] In one embodiment, the chloride ion solution includes one or more of a sodium chloride solution, a potassium chloride solution and a hydrochloric acid solution.

[0024] In one of the embodiments, the photovoltaic module welding ribbon includes a copper substrate and a coating layer stacked on the surface of the copper substrate, and the coating layer includes tin, lead and silver.

[0025] In one embodiment, the separation process includes one or more of mechanical separation, pyrolysis separation and pulverization.

[0026] A second aspect of the present application provides a recovery device, comprising:

[0027] An acid leaching tank, used to store nitric acid solution and perform acid leaching on the solder strips of photovoltaic modules to obtain copper-rich leaching residue and a first solution;

[0028] A first alkaline solution storage tank, used for storing a first alkaline solution;

[0029] a first precipitation reaction tank, connected to the filtrate outlet of the acid leaching tank and the first alkaline solution storage tank, and used to mix the first solution with the first alkaline solution to prepare a tin-rich solid and a second solution;

[0030] A second alkaline solution storage tank, used for storing a second alkaline solution;

[0031] a second precipitation reaction tank, connected to the filtrate outlet of the first precipitation reaction tank and the second alkaline solution storage tank, and used to mix the second solution with the second alkaline solution to prepare copper-rich solids and a third solution;

[0032] a third alkaline solution storage tank, used for storing a third alkaline solution; and,

[0033] The third precipitation reaction tank is connected to the filtrate outlet of the second precipitation reaction tank and the third alkaline solution storage tank, and is used to mix the third solution and the third alkaline solution to prepare lead-rich solid and a fourth solution.

[0034] In one embodiment, the recovery device further comprises:

[0035] a chloride ion solution storage tank, used for storing the chloride ion solution; and,

[0036] The fourth precipitation reaction tank is connected with the filtrate outlet of the third precipitation reaction tank and the chloride ion-containing solution storage tank, and is used to mix the fourth solution with the chloride ion-containing solution to prepare silver chloride solid.

[0037] In the recovery method provided by the present application, the photovoltaic module welding strip is acid-leached by a nitric acid solution of a relatively low mass concentration. At this time, the undissolved metal is copper, and a copper-rich leached residue is obtained; dissolved metal elements such as Cu, Sn and Pb are converted into metal ions and exist in the first solution, and the pH of the first solution is less than 1; an alkaline solution is added to adjust the pH value to 1-2, and a white Sn(OH)4 precipitate is produced, that is, a tin-rich solid and a second solution are obtained; the pH value of the second solution is further adjusted to 5-6.5, and a blue precipitate Cu(OH)2 is produced, that is, a copper-rich solid and a third solution are obtained; the pH value of the third solution is adjusted to 8-10, and a white precipitate Pb(OH)2 is obtained, that is, a lead-rich solid and a fourth solution are obtained. The present application regulates the pH value of the reaction solution, and can gradually produce the corresponding metal hydroxide precipitate, and the corresponding pH values ​​when producing tin-rich solids, copper-rich solids and lead-rich solids are greatly different, and the color of the precipitated intermediate copper-rich solid is different from that of the tin-rich solid and the lead-rich solid, thereby effectively realizing the effective separation and recovery of tin, copper and lead.

[0038] In summary, the recycling method provided in this application can effectively separate and recycle tin, copper and lead, and realize the recycling of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 A schematic diagram of the structure of a recovery device provided in one embodiment of the present application;

[0041] Figure 2 A schematic structural diagram of a recovery device provided in another embodiment of the present application. DETAILED DESCRIPTION

[0042] The following is a further complete and clear description of the metal recovery method and recovery device in the photovoltaic module welding ribbon of the present application in combination with specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0043] It should be understood that the terms described in this application are only for describing specific embodiments and are not intended to limit this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present application. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0044] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art in the field described in the present application. Although the present application only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of any conflict with any incorporated document, the content of this specification shall prevail.

[0045] As used herein, "one or more" refers to any one, any two, or any two or more of the listed items.

[0046] In this application, "first aspect", "second aspect", "third aspect", "fourth aspect", "fifth aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", "fifth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0047] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0048] In addition, for the numerical ranges in this application, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or intermediate value in the stated range and any other stated value or intermediate value in the stated range is also included in this application. The upper and lower limits of these smaller ranges can be independently included or excluded in the range. In other words, unless otherwise indicated, all ranges disclosed herein are understood to include any and all subranges included therein.

[0049] The percentage contents involved in this application, unless otherwise specified, refer to mass percentage for solid-liquid mixing and solid-solid mixing, and refer to volume percentage for liquid-liquid mixing.

[0050] The percentage concentrations mentioned in this application, unless otherwise specified, refer to the final concentration, which refers to the percentage of the added component in the system after the addition of the component.

[0051] The temperature parameters in this application, unless otherwise specified, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the accuracy range of instrument control.

[0052] In a first aspect of the present application, a method for recovering metal from a photovoltaic module welding ribbon is provided, comprising the following steps:

[0053] S10, disassembling the waste photovoltaic modules to obtain the photovoltaic module welding strips;

[0054] S20, performing acid leaching treatment on the photovoltaic module welding strip using a nitric acid solution to prepare copper-rich leaching residue and a first solution;

[0055] S30, adding a first alkaline solution to the first solution to adjust the pH value of the first solution to 1-2, to prepare a tin-rich solid and a second solution;

[0056] S40, adding a second alkaline solution to the second solution to adjust the pH value of the second solution to 5-6.5, to prepare a copper-rich solid and a third solution;

[0057] S50, adding a third alkaline solution to the third solution to make the pH value of the third solution be 8-10, to prepare a lead-rich solid and a fourth solution;

[0058] Wherein, the mass concentration of the nitric acid solution is 5%~10%.

[0059] In the recovery method provided by the present application, the photovoltaic module welding strip is acid-leached by a nitric acid solution of a relatively low mass concentration. At this time, the undissolved metal is copper, and a copper-rich leached residue is obtained; dissolved metal elements such as Cu, Sn and Pb are converted into metal ions and exist in the first solution, and the pH of the first solution is less than 1; an alkaline solution is added to adjust the pH value to 1-2, and a white Sn(OH)4 precipitate is produced, that is, a tin-rich solid and a second solution are obtained; the pH value of the second solution is further adjusted to 5-6.5, and a blue precipitate Cu(OH)2 is produced, that is, a copper-rich solid and a third solution are obtained; the pH value of the third solution is adjusted to 8-10, and a white precipitate Pb(OH)2 is obtained, that is, a lead-rich solid and a fourth solution are obtained. The present application regulates the pH value of the reaction solution, and can gradually produce the corresponding metal hydroxide precipitate, and the corresponding pH values ​​when producing tin-rich solids, copper-rich solids and lead-rich solids are greatly different, and the color of the precipitated intermediate copper-rich solid is different from that of the tin-rich solid and the lead-rich solid, thereby effectively realizing the effective separation and recovery of tin, copper and lead.

[0060] In summary, the recycling method provided in this application can effectively separate and recycle tin, copper and lead, and realize the recycling of resources.

[0061] In one example, in step S10, the separation process includes one or more of mechanical separation, pyrolysis separation and pulverization.

[0062] Disassembling PV modules can effectively separate metal-rich components such as PV module solder ribbons to improve recycling efficiency.

[0063] In one example, in step S20, the acid leaching temperature is 15°C to 35°C. In the present application, the acid leaching temperature is room temperature, which is conducive to saving energy costs. Specifically, the acid leaching temperature includes but is not limited to 15°C, 18°C, 20°C, 22°C, 25°C, 28°C, 30°C, 32°C, 35°C, or any two of the above point values ​​as end values.

[0064] In one example, in step S20, the acid leaching treatment time is 1 hour to 4 hours.

[0065] In one of the examples, in step S20, an ultrasonic power of 400W to 600W is applied during the acid leaching treatment. When the acid leaching treatment is performed, the ultrasonic treatment is performed simultaneously, which can promote the reaction between the nitric acid solution and the photovoltaic module welding strip, and can accelerate the dissolution rate of the metal, thereby improving the efficiency of the acid leaching treatment, which is conducive to shortening the time of the acid leaching treatment. It can be understood that the selected ultrasonic power can be selected from any value between 400W and 600W. Specifically, the ultrasonic power includes but is not limited to 400W, 420W, 450W, 480W, 500W, 520W, 550W, 580W or 600W, or is within the range consisting of any two of the above point values ​​as end values. In one of the examples, the time for applying an ultrasonic power of 400W to 600W is 20min to 40min.

[0066] It can be understood that in step S20, the mass concentration of the nitric acid solution of the present application can be selected from any value between 5% and 10%. Specifically, the mass concentration of the nitric acid solution includes but is not limited to 5%, 6%, 7%, 8%, 9%, 10%, or a range consisting of any two of the above point values ​​as end values.

[0067] In step S30, the pH value of the first solution can be selected from any value between 1 and 2. Specifically, the pH of the first solution includes but is not limited to 1, 1.1, 1.2, 1.4, 1.6, 1.8, 2, or a range consisting of any two of the above point values ​​as end values.

[0068] In step S40, the pH value of the second solution can be selected from any value between 5 and 6.5. Specifically, the pH value of the second solution includes but is not limited to 5, 5.2, 5.5, 5.8, 6, 6.2, 6.3, 6.4, 6.5, or a range consisting of any two of the above values ​​as end values.

[0069] In step S50, the pH value of the third solution can be selected from any value between 8 and 10. Specifically, the pH value of the third solution includes but is not limited to 8, 8.2, 8.5, 8.8, 9, 9.2, 9.5, 9.8, 10, or a range consisting of any two of the above point values ​​as end values.

[0070] To achieve accurate control of the pH value, the pH value is kept stable. In one example, in step S30, the mass concentration of the first alkaline solution is 5% to 10%. It is understandable that the mass concentration of the first alkaline solution can be selected from any value between 5% and 10%. Specifically, the mass concentration of the first alkaline solution includes but is not limited to 5%, 5.5%, 5.8%, 6%, 6.2%, 6.5%, 6.8%, 7%, 7.2%, 7.5%, 7.8%, 8%, 8.5%, 9%, 9.5%, 10%, or any two of the above point values ​​are used as the range of the end value.

[0071] In one example, in step S40, the mass concentration of the second alkaline solution is 5% to 10%. It is understandable that the mass concentration of the second alkaline solution can be selected from any value between 5% and 10%. Specifically, the mass concentration of the second alkaline solution includes but is not limited to 5%, 5.5%, 5.8%, 6%, 6.2%, 6.5%, 6.8%, 7%, 7.2%, 7.5%, 7.8%, 8%, 8.5%, 9%, 9.5%, 10%, or any two of the above point values ​​as the range of end values.

[0072] In one example, in step S50, the mass concentration of the third alkaline solution is 5% to 10%. It is understandable that the mass concentration of the third alkaline solution can be selected from any value between 5% and 10%. Specifically, the mass concentration of the third alkaline solution includes but is not limited to 5%, 5.5%, 5.8%, 6%, 6.2%, 6.5%, 6.8%, 7%, 7.2%, 7.5%, 7.8%, 8%, 8.5%, 9%, 9.5%, 10%, or any two of the above points are used as the range of the end value.

[0073] In one example, the first alkaline solution, the second alkaline solution and the third alkaline solution are each independently selected from one or more of a NaOH solution and a KOH solution.

[0074] In one example, the recovery method further includes a step of treating the fourth solution, specifically including:

[0075] S60, adding a chloride ion solution into the fourth solution to prepare silver chloride solid.

[0076] In one example, in step S60, the chloride ion solution includes one or more of a sodium chloride solution, a potassium chloride solution, and a hydrochloric acid solution.

[0077] In one specific example, the mass concentration of the sodium chloride solution is 0.01 g / mL to 0.03 g / mL. It is understandable that the mass concentration of the sodium chloride solution includes but is not limited to 0.01 g / mL, 0.015 g / mL, 0.02 g / mL, 0.025 g / mL, 0.028 g / mL or 0.03 g / mL, or is within the range of any two of the above point values ​​as end values.

[0078] In one specific example, the mass concentration of the potassium chloride solution is 0.01 g / mL to 0.03 g / mL. It is understandable that the mass concentration of the potassium chloride solution includes but is not limited to 0.01 g / mL, 0.015 g / mL, 0.02 g / mL, 0.025 g / mL, 0.028 g / mL or 0.03 g / mL, or is within the range of any two of the above point values ​​as end values.

[0079] In one example, the photovoltaic module welding ribbon includes a copper substrate and a coating layer stacked on the surface of the copper substrate, and the coating layer includes tin, lead and silver elements.

[0080] In one specific example, the recycling method comprises the following steps:

[0081] S10, the step of disassembling the photovoltaic module to obtain the photovoltaic module welding strip, wherein the disassembly process includes one or more of mechanical separation, pyrolysis separation and crushing;

[0082] S20, using a nitric acid solution with a mass concentration of 5% to 10% to perform acid leaching on the photovoltaic module welding strip to prepare copper-rich leaching residue and a first solution;

[0083] S30, adding a first alkaline solution to the first solution to adjust the pH value of the first solution to 1-2, to prepare a tin-rich solid and a second solution;

[0084] S40, adding a second alkaline solution to the second solution to adjust the pH value of the second solution to 5-6.5, to prepare a copper-rich solid and a third solution;

[0085] S50, adding a third alkaline solution to the third solution to make the pH value of the third solution be 8-10, to prepare a lead-rich solid and a fourth solution;

[0086] S60, adding a chloride ion solution into the fourth solution to prepare silver chloride solid.

[0087] See also Figure 1 In a second aspect of the present application, a recovery device is provided, comprising:

[0088] An acid leaching tank, used to store nitric acid solution and perform acid leaching on the solder strips of photovoltaic modules to obtain copper-rich leaching residue and a first solution;

[0089] A first alkaline solution storage tank, used for storing a first alkaline solution;

[0090] a first precipitation reaction tank, connected to the filtrate outlet of the acid leaching tank and the first alkaline solution storage tank, and used to mix the first solution with the first alkaline solution to prepare a tin-rich solid and a second solution;

[0091] A second alkaline solution storage tank, used for storing a second alkaline solution;

[0092] a second precipitation reaction tank, connected to the filtrate outlet of the first precipitation reaction tank and the second alkaline solution storage tank, and used to mix the second solution with the second alkaline solution to prepare copper-rich solids and a third solution;

[0093] a third alkaline solution storage tank, used for storing a third alkaline solution; and,

[0094] The third precipitation reaction tank is connected to the filtrate outlet of the second precipitation reaction tank and the third alkaline solution storage tank, and is used to mix the third solution and the third alkaline solution to prepare lead-rich solid and a fourth solution.

[0095] In one example, the recovery device further comprises:

[0096] A chloride ion solution storage tank, used for storing the chloride ion solution;

[0097] The fourth precipitation reaction tank is connected with the filtrate outlet of the third precipitation reaction tank and the chloride ion-containing solution storage tank, and is used to mix the fourth solution with the chloride ion-containing solution to prepare silver chloride solid.

[0098] It can be understood that when the mass concentrations of the first alkaline solution, the second alkaline solution and the third alkaline solution are the same, the first alkaline solution storage tank, the second alkaline solution storage tank and the third alkaline solution storage tank can be the same alkaline solution storage tank. In this case, the structural schematic diagram of the corresponding recovery device is as follows: Figure 2 shown.

[0099] The following further specific examples are provided to explain the present application in detail. It should also be understood that the following examples are only used to further explain the present application and cannot be understood as limiting the scope of protection of the present application. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present application belong to the scope of protection of the present application. The specific process parameters of the following embodiments are also only examples within a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not necessarily limited to the specific values ​​of the embodiments below.

[0100] Example 1

[0101] Recovery device and connection method: Figure 2 shown. The recovery device includes: an acid leaching tank, which is used to store nitric acid solution and perform acid leaching treatment on the welding strip of the photovoltaic module to obtain copper-rich leaching residue and a first solution; an alkaline solution storage tank, which is used to store alkaline solution; a first precipitation reaction tank, which is connected to the filtrate outlet of the acid leaching tank and the alkaline solution storage tank, and is used to mix the first solution and the alkaline solution to prepare a tin-rich solid and a second solution; a second precipitation reaction tank, which is connected to the filtrate outlet of the first precipitation reaction tank and the alkaline solution storage tank, and is used to mix the second solution and the alkaline solution to prepare a copper-rich solid and a third solution; a third precipitation reaction tank, which is connected to the filtrate outlet of the second precipitation reaction tank and the alkaline solution storage tank, and is used to mix the third solution and the alkaline solution to prepare a lead-rich solid and a fourth solution; a chloride ion solution storage tank, which is used to store a chloride ion solution; a fourth precipitation reaction tank, which is connected to the filtrate outlet of the third precipitation reaction tank and the chloride ion solution storage tank, and is used to mix the fourth solution and the chloride ion solution to prepare a silver-rich silver chloride solid.

[0102] A method for recovering copper, tin, lead and silver from photovoltaic module welding strips comprises the following steps:

[0103] (1) Disassemble the waste photovoltaic modules by physical method (mechanical separation), obtain the photovoltaic module welding strips, and clean the photovoltaic module welding strips with deionized water;

[0104] (2) treating the photovoltaic module welding strip with acid in a nitric acid solution, wherein the concentration of the nitric acid solution is 5%, the temperature of the acid leaching treatment is room temperature, and the reaction time is 4 hours; filtering to prepare copper-rich leaching residue and a first solution; washing and drying the copper-rich leaching residue to obtain high-purity copper;

[0105] (3) adding a 5% sodium hydroxide solution to the first solution and adjusting the pH value to 1-2, thereby generating a white precipitate Sn(OH)4. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a tin-rich solid and a second solution;

[0106] (4) adding a 5% sodium hydroxide solution to the second solution and adjusting the pH value to 5-6.5, thereby generating a blue precipitate of Cu(OH)2. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a copper-rich solid and a third solution;

[0107] (5) adding a 5% sodium hydroxide solution to the third solution and adjusting the pH value to 8-10, thereby generating a white precipitate of Pb(OH)2. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a lead-rich solid and a fourth solution;

[0108] (6) adding a sodium chloride solution with a mass volume ratio of 0.02 g / mL to the fourth solution, allowing the solution to stand to obtain a white precipitate of AgCl, and after the precipitate is no longer produced, separating the precipitate from the solution to prepare a silver chloride solid and a fifth solution;

[0109] (7) The fifth solution is processed centrally.

[0110] Example 2

[0111] Recovery device and connection method: same as Example 1.

[0112] A method for recovering copper, tin, lead and silver from photovoltaic module welding strips comprises the following steps:

[0113] (1) Disassemble the waste photovoltaic modules by physical method (mechanical separation), obtain the photovoltaic module welding strips, and clean the photovoltaic module welding strips with deionized water;

[0114] (2) subjecting the photovoltaic module welding strip to acid leaching treatment in a nitric acid solution, wherein the concentration of the nitric acid solution is 5%, the temperature of the acid leaching treatment is room temperature, the reaction time is 2.5 hours, wherein an ultrasonic treatment is performed for 0.5 hours, and the ultrasonic treatment power is 500W; filtering to prepare copper-rich leaching residue and a first solution; washing and drying the copper-rich leaching residue to obtain high-purity copper;

[0115] (3) adding a 5% sodium hydroxide solution to the first solution and adjusting the pH value to 1-2, thereby generating a white precipitate Sn(OH)4. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a tin-rich solid and a second solution;

[0116] (4) adding a 5% sodium hydroxide solution to the second solution and adjusting the pH value to 5-6.5, thereby generating a blue precipitate of Cu(OH)2. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a copper-rich solid and a third solution;

[0117] (5) adding a 5% sodium hydroxide solution to the third solution and adjusting the pH value to 8-10, thereby generating a white precipitate of Pb(OH)2. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a lead-rich solid and a fourth solution;

[0118] (6) adding a sodium chloride solution with a mass volume ratio of 0.02 g / mL to the fourth solution, allowing the solution to stand to obtain a white precipitate of AgCl, and after the precipitate is no longer produced, separating the precipitate from the solution to prepare a silver chloride solid and a fifth solution;

[0119] (7) The fifth solution is processed centrally.

[0120] Example 3

[0121] Recovery device and connection method: same as Example 1.

[0122] The method for recovering copper, tin, lead and silver in the solder strip of a photovoltaic module is basically the same as that in Example 1, the main difference being that the concentration of the nitric acid solution in step (2) of Example 3 is 10% and the reaction time is 2 h.

[0123] Example 4

[0124] Recovery device and connection method: same as Example 1.

[0125] The method for recovering copper, tin, lead and silver in the solder strip of a photovoltaic module is basically the same as that in Example 1, the main difference being that the concentration of the nitric acid solution in step (2) of Example 4 is 20% and the reaction time is 1 h.

[0126] Example 5

[0127] Recovery device and connection method: same as Example 1.

[0128] The method for recovering copper, tin, lead and silver in the solder strip of a photovoltaic module is basically the same as that in Example 1, the main difference is that the concentration of the nitric acid solution in step (2) of Example 5 is 20%, and the reaction time is 1 hour; at the same time, the mass concentration of the sodium hydroxide solution selected in steps (3) to (5) of Example 5 is 10%.

[0129] Example 6

[0130] Recovery device and connection method: same as Example 1.

[0131] The method for recovering copper, tin, lead and silver from the soldering ribbon of a photovoltaic module is basically the same as that in Example 1, except that in step (1) of Example 6, the soldering ribbon of the photovoltaic module separated by physical method (high temperature pyrolysis) is cleaned with deionized water.

[0132] Example 7

[0133] Recovery device and connection method: same as Example 1.

[0134] The method for recovering copper, tin, lead and silver from the soldering ribbon of a photovoltaic module is basically the same as that in Example 2, except that in step (1) of Example 7, the soldering ribbon of the photovoltaic module separated by physical method (high temperature pyrolysis) is cleaned with deionized water.

[0135] Example 8

[0136] Recovery device and connection method: same as Example 1.

[0137] The method for recovering copper, tin, lead and silver in the soldering ribbon of a photovoltaic module is basically the same as that in Example 3, except that in step (1) of Example 8, the soldering ribbon of the photovoltaic module separated by physical method (high temperature pyrolysis) is cleaned with deionized water.

[0138] Example 9

[0139] Recovery device and connection method: same as Example 1.

[0140] The method for recovering copper, tin, lead and silver from the soldering ribbon of a photovoltaic module is basically the same as that in Example 4, except that in step (1) of Example 9, the soldering ribbon of the photovoltaic module separated by physical method (high temperature pyrolysis) is cleaned with deionized water.

[0141] Example 10

[0142] Recovery device and connection method: same as Example 1.

[0143] The method for recovering copper, tin, lead and silver in the soldering ribbon of a photovoltaic module is basically the same as that in Example 5, the main difference being that in step (1) of Example 10, the soldering ribbon of the photovoltaic module separated by a physical method (high temperature pyrolysis) is cleaned with deionized water.

[0144] Comparative Example 1

[0145] Recovery device and connection method: same as Example 1.

[0146] A method for recovering copper, tin, lead and silver from photovoltaic module welding strips comprises the following steps:

[0147] (1) Disassemble the waste photovoltaic modules by physical method (mechanical separation), obtain the photovoltaic module welding strips, and clean the photovoltaic module welding strips with deionized water;

[0148] (2) treating the photovoltaic module solder strip with acid in a nitric acid solution, wherein the concentration of the nitric acid solution is 2%, the pH value is adjusted to be 1-2, the temperature of the acid treatment is room temperature, and the reaction time is 4 hours; filtering to prepare a first leaching residue and a first solution; washing and drying the first leaching residue to obtain high-purity copper and tin-rich solids;

[0149] (3) adding a 5% sodium hydroxide solution to the first solution and adjusting the pH value to 5-6.5, thereby generating a blue precipitate of Cu(OH)2. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a second solid and a second solution;

[0150] (5) adding a 5% sodium hydroxide solution to the second solution and adjusting the pH value to 8-10, thereby generating a white precipitate of Pb(OH)2. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a lead-rich solid and a third solution;

[0151] (6) adding a sodium chloride solution with a mass volume ratio of 0.02 g / mL to the third solution, allowing the solution to stand to obtain a white precipitate of AgCl, and after the precipitate is no longer produced, separating the precipitate from the solution to prepare a silver chloride solid and a fourth solution;

[0152] (7) The fourth solution is processed centrally.

[0153] Comparative Example 2

[0154] Recovery device and connection method: same as Example 1.

[0155] A method for recovering copper, tin, lead and silver from photovoltaic module welding strips comprises the following steps:

[0156] (1) Disassemble the waste photovoltaic modules by physical method (mechanical separation), obtain the photovoltaic module welding strips, and clean the photovoltaic module welding strips with deionized water;

[0157] (2) treating the photovoltaic module welding strip with acid in a nitric acid solution, wherein the concentration of the nitric acid solution is 5%, the temperature of the acid leaching treatment is room temperature, and the reaction time is 4 hours; filtering to prepare copper-rich leaching residue and a first solution; washing and drying the copper-rich leaching residue to obtain high-purity copper;

[0158] (3) adding a 5% by mass sodium hydroxide solution to the first solution and adjusting the pH value to 5-6.5, thereby generating a bluish-white precipitate. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a third solid and a third solution;

[0159] (4) adding a 5% sodium hydroxide solution to the third solution and adjusting the pH value to 8-10, thereby generating a white precipitate of Pb(OH)2. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a lead-rich solid and a fourth solution;

[0160] (5) adding a sodium chloride solution with a mass volume ratio of 0.02 g / mL to the fourth solution, allowing the solution to stand to obtain a white precipitate of AgCl, and after the precipitate is no longer produced, separating the precipitate from the solution to prepare a silver chloride solid and a fifth solution;

[0161] (6) The fifth solution is processed centrally.

[0162] Comparative Example 3

[0163] Recovery device and connection method: same as Example 1.

[0164] A method for recovering copper, tin, lead and silver from photovoltaic module welding strips comprises the following steps:

[0165] (1) Disassemble the waste photovoltaic modules by physical method (mechanical separation), obtain the photovoltaic module welding strips, and clean the photovoltaic module welding strips with deionized water;

[0166] (2) treating the photovoltaic module welding strip with acid in a nitric acid solution, wherein the concentration of the nitric acid solution is 5%, the temperature of the acid leaching treatment is room temperature, and the reaction time is 4 hours; filtering to prepare copper-rich leaching residue and a first solution; washing and drying the copper-rich leaching residue to obtain high-purity copper;

[0167] (3) adding a 5% by mass sodium hydroxide solution to the first solution and adjusting the pH value to 8-10, thereby generating a precipitate. After the precipitate is no longer generated, separating the precipitate from the solution to prepare a fourth solid and a fourth solution;

[0168] (4) adding a sodium chloride solution with a mass volume ratio of 0.02 g / mL to the fourth solution, allowing the solution to stand to obtain a white precipitate of AgCl, and after the precipitate is no longer produced, separating the precipitate from the solution to prepare a silver chloride solid and a fifth solution;

[0169] (5) The fifth solution is processed centrally.

[0170] The purity of the copper-rich leaching residue, tin-rich solid, copper-rich solid, lead-rich solid and silver chloride solid prepared in each embodiment was tested. Among them, the purity of the copper-rich leaching residue = the mass of copper / the mass of the total copper-rich leaching residue × 100%, the purity of the tin-rich solid = the mass of Sn(OH)4 / the mass of the total tin-rich solid × 100%; the purity of the copper-rich solid = the mass of Cu(OH)2 / the mass of the total copper-rich solid × 100%; the purity of the lead-rich solid = the mass of Pb(OH)2 / the mass of the total lead-rich solid × 100%; the purity of the silver chloride solid = the mass of AgCl / the mass of the total silver-rich solid × 100%. The recovery rate of tin = (mass of solid Sn(OH)4 / 186.74×118.71) / (mass of tin in the initial photovoltaic module welding strip) × 100%, where "mass of solid Sn(OH)4 / 186.74×118.71" is the mass of Sn element in solid Sn(OH)4; the recovery rate of copper = (mass of solid Cu(OH)2 / 97.51×63.5+mass of copper in copper-rich leaching slag) / mass of copper in the initial photovoltaic module welding strip × 100%, where "mass of solid Cu(OH)2 / 97.51×63.5" is the mass of Cu element in solid Cu(OH)2 The mass of lead in the solder strip of the initial photovoltaic module is 241.21 × 207.2, and the recovery rate of lead = (mass of solid Pb(OH)2 / 241.21 × 207.2) / mass of lead in the initial photovoltaic module solder strip × 100%, where "mass of solid Pb(OH)2 / 241.21 × 207.2" is the mass of Pb element in solid Pb(OH)2; the recovery rate of silver = (mass of solid AgCl / 143.32 × 107.87) / (mass of silver in the initial photovoltaic module solder strip) × 100%, where "mass of solid AgCl / 143.32 × 107.87" is the mass of Ag element in solid AgCl; the test results are shown in Table 1.

[0171] Table 1

[0172]

[0173] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0174] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A method for recovering metal from photovoltaic module welding strips, characterized in that: The following steps are involved: Disassemble and process the waste photovoltaic modules to obtain the photovoltaic module welding strips; The photovoltaic module welding strip is subjected to acid leaching treatment using a nitric acid solution to prepare copper-rich leaching residue and a first solution; Adding a first alkaline solution to the first solution to adjust the pH value of the first solution to 1-2, thereby preparing a tin-rich solid and a second solution; Adding a second alkaline solution to the second solution to adjust the pH value of the second solution to 5-6.5, to prepare a copper-rich solid and a third solution; Adding a third alkaline solution to the third solution to adjust the pH value of the third solution to 8-10, thereby preparing a lead-rich solid and a fourth solution; Wherein, the mass concentration of the nitric acid solution is 5%~10%.

2. The method for recovering metal from photovoltaic module welding strip according to claim 1, characterized in that: The recovery method has one or more of the following characteristics: (1) The mass concentration of the first alkaline solution is 5% to 10%; (2) The mass concentration of the second alkaline solution is 5% to 10%; (3) The mass concentration of the third alkaline solution is 5% to 10%.

3. The method for recovering metal from photovoltaic module welding strip according to claim 1, characterized in that: The first alkaline solution, the second alkaline solution and the third alkaline solution are each independently selected from one or more of a NaOH solution and a KOH solution.

4. The method for recovering metal from photovoltaic module welding strip according to any one of claims 1 to 3, characterized in that: The process parameters of the acid leaching treatment have one or more of the following characteristics: (1) The acid leaching temperature is 15°C to 35°C, (2) The acid leaching treatment time is 1h~4h; (3) Applying an ultrasonic power of 400 W to 600 W during the acid leaching treatment.

5. The method for recovering metal from photovoltaic module welding strip according to any one of claims 1 to 3, characterized in that: The recovery method further comprises the step of treating the fourth solution, specifically comprising: A chloride ion solution is added to the fourth solution to prepare silver chloride solid.

6. The method for recovering metal from photovoltaic module welding strips according to claim 5, characterized in that: The chloride ion-containing solution includes one or more of a sodium chloride solution, a potassium chloride solution and a hydrochloric acid solution.

7. The method for recovering metal from photovoltaic module welding strip according to any one of claims 1 to 3, characterized in that: The photovoltaic module welding strip comprises a copper substrate and a coating layer stacked on the surface of the copper substrate, wherein the coating layer comprises tin, lead and silver elements.

8. The method for recovering metal from photovoltaic module welding strips according to claim 7, characterized in that: The separation process includes one or more of mechanical separation, pyrolysis separation and pulverization.

9. A recovery device, characterized in that: include: An acid leaching tank, used to store nitric acid solution and perform acid leaching on the solder strips of photovoltaic modules to obtain copper-rich leaching residue and a first solution; A first alkaline solution storage tank, used for storing a first alkaline solution; a first precipitation reaction tank, connected to the filtrate outlet of the acid leaching tank and the first alkaline solution storage tank, and used to mix the first solution with the first alkaline solution to prepare a tin-rich solid and a second solution; A second alkaline solution storage tank, used for storing a second alkaline solution; a second precipitation reaction tank, connected to the filtrate outlet of the first precipitation reaction tank and the second alkaline solution storage tank, and used to mix the second solution with the second alkaline solution to prepare copper-rich solids and a third solution; A third alkaline solution storage tank, used for storing a third alkaline solution; and, The third precipitation reaction tank is connected to the filtrate outlet of the second precipitation reaction tank and the third alkaline solution storage tank, and is used to mix the third solution and the third alkaline solution to prepare lead-rich solid and a fourth solution.

10. The recovery device according to claim 9, characterized in that: The recovery device also includes: a chloride ion solution storage tank, used for storing the chloride ion solution; and, The fourth precipitation reaction tank is connected with the filtrate outlet of the third precipitation reaction tank and the chloride ion-containing solution storage tank, and is used to mix the fourth solution with the chloride ion-containing solution to prepare silver chloride solid.

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