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CN-121988585-A - Method for recycling metal and silicon in waste crystalline silicon photovoltaic module

CN121988585ACN 121988585 ACN121988585 ACN 121988585ACN-121988585-A

Abstract

The invention discloses a method for recycling metal and silicon in a waste crystalline silicon photovoltaic module, which comprises the steps of disassembling the waste crystalline silicon photovoltaic module to obtain a frameless module, pyrolyzing, washing and drying the frameless module to obtain a dry crystalline silicon battery piece, carrying out mechanochemical activation treatment on the dry crystalline silicon battery piece to obtain activated crystalline silicon battery powder, carrying out acid leaching treatment on the activated crystalline silicon battery powder, filtering to obtain leaching solution containing Ag and Al and silicon slag, carrying out separation and purification treatment on the leaching solution to obtain Ag and Al metal, adding carbon black into the silicon slag, carrying out carbon thermal shock treatment, and crushing and grinding the obtained reaction product to obtain a SiC sample. According to the invention, through a synergistic strategy of mechanical activation enhanced leaching-high-value conversion of carbon thermal shock, the full component recovery of Ag, al and Si resources in the waste crystalline silicon photovoltaic module is realized, and the recovery process flow is simple, safe and environment-friendly.

Inventors

  • LI JINHUI
  • WANG LANBIN
  • ZHANG BEIKAI
  • YU JIADONG
  • LIU LILI

Assignees

  • 清华大学

Dates

Publication Date
20260508
Application Date
20251230

Claims (10)

  1. 1. The method for recycling the metal and the silicon in the waste crystalline silicon photovoltaic module is characterized by comprising the following steps of: (1) Disassembling the waste crystalline silicon photovoltaic module, and removing the aluminum alloy frame and the junction box to obtain a frameless module; (2) Carrying out pyrolysis treatment on the frameless component to obtain a crystalline silicon battery piece, and washing and drying the crystalline silicon battery piece to obtain a dry crystalline silicon battery piece; (3) Mechanically activating the dry crystalline silicon battery piece to obtain activated crystalline silicon battery powder; (4) Carrying out acid leaching treatment on the activated crystalline silicon battery powder, and filtering to obtain leaching liquid and silicon slag, wherein the leaching liquid contains Ag metal and Al metal; (5) Separating and purifying the leaching solution obtained in the step (4), and respectively recovering Ag metal and Al metal; (6) Adding carbon black into the silicon slag obtained in the step (4), and mixing and grinding to obtain a mixed material; (7) And (3) after carrying out carbon thermal shock treatment on the mixed material, crushing and grinding the obtained reaction product to obtain a SiC sample.
  2. 2. The method for recycling metal and silicon in a waste crystalline silicon photovoltaic module according to claim 1, wherein in the step (2), the pyrolysis treatment is performed in an air atmosphere, and the flow rate of the air is 100-150mL/min; and/or the heating rate of the pyrolysis treatment is 5-20 ℃ per minute, the pyrolysis temperature is 450-550 ℃, and the pyrolysis time is 1-1.5h.
  3. 3. The method for recycling metal and silicon in a waste crystalline silicon photovoltaic module according to claim 1, wherein in the step (2), the drying mode is vacuum drying, the drying temperature is 50-70 ℃, and the drying time is 1.5-2.5h.
  4. 4. The method for recycling metal and silicon in the discarded crystalline silicon photovoltaic module according to claim 1, wherein in the step (3), the mechanochemical activation treatment is performed in a planetary ball mill, the ball milling speed is 400-800rpm, the ball milling time is 60-120min, and the ball-to-material ratio is 10:1.
  5. 5. The method for recycling metal and silicon in a waste crystalline silicon photovoltaic module according to claim 1, wherein in the step (4), the acid solution used in the acid leaching treatment is a nitric acid solution, and the concentration of the nitric acid solution is 0.5-2.5M.
  6. 6. The method for recycling metal and silicon in a waste crystalline silicon photovoltaic module according to claim 1, wherein in the step (4), the liquid-solid ratio of the acid leaching treatment is 20:1, the temperature of the acid leaching treatment is 40-60 ℃, and the time is 60-120min.
  7. 7. The method for recycling metal and silicon in a waste crystalline silicon photovoltaic module according to claim 1, wherein in the step (6), the mass ratio of the silicon slag to the carbon black is 1:1-1:3.
  8. 8. The method for recycling metal and silicon in a waste crystalline silicon photovoltaic module according to claim 1, wherein in the step (7), the carbon thermal shock treatment is performed in an argon atmosphere, and the flow rate of the argon is 80-120mL/min.
  9. 9. The method for recycling metal and silicon in a waste crystalline silicon photovoltaic module according to claim 1, wherein in the step (7), the heating rate of the carbon thermal shock treatment is 1000-2000 ℃ per minute, the heat preservation temperature is 1800-2000 ℃ and the heat preservation time is 10-30s.
  10. 10. The method for recycling metal and silicon in a waste crystalline silicon photovoltaic module according to claim 1, wherein in the step (7), the particle size of the SiC sample is 50-100nm.

Description

Method for recycling metal and silicon in waste crystalline silicon photovoltaic module Technical Field The invention belongs to the field of hydrometallurgy and recycling of waste crystalline silicon photovoltaic modules, and particularly relates to a method for recycling metal and silicon in a waste crystalline silicon photovoltaic module. Background The explosive growth of the global photovoltaic industry promotes the popularization of clean energy, but the subsequent proliferation of waste crystalline silicon photovoltaic modules has become a double challenge of resource recycling and environmental management. According to the predictions of International Energy Agency (IEA) and International renewable energy agency (IRENA), the waste amount of the global retired photovoltaic component in 2030 is 1.7-8 million tons, and the waste amount is more rapidly increased to 60-78 million tons in 2050, wherein the crystalline silicon photovoltaic component accounts for more than 90 percent. The high-value battery sheet materials (Si accounting for 4.4 percent, ag accounting for 0.03 percent and Al accounting for 0.3 percent) and harmful components (Pb) contained in the components are mishandled, so that serious resource waste and environmental risks are caused. Among them, ag is a scarce metal with crust abundance of only 0.07ppm, and conventional landfill treatment can lead to annual loss of potential resources of over 3 ten thousand tons. Although crystalline silicon component recycling can reduce 74% terrestrial ecotoxicity and 26% Global Warming Potential (GWP), current battery sheet metal and Si recycling technologies are still limited by the contradiction between efficiency and economy, and full component high value utilization is difficult to achieve. In the existing hydrometallurgical recovery method, although higher metal leaching rate can be realized by single acid leaching, the problems of high reagent consumption, serious silicon loss and the like exist, for example, leaching of more than 99% of Ag by 60% nitric acid at 50 ℃ for 1 hour can be realized, but Si loss is more than 20% due to high concentration of HF required by SiN X etching, the recovery efficiency of Ag is lower due to easiness in forming precipitation with silver although the leaching rate of 99% of Al is realized by a hydrochloric acid and sulfuric acid system, the recovery efficiency of metal can be improved by a green leaching agent, the reagent can be recycled, the cost is higher, the time consumption is long due to biological leaching, and the defects of insufficient Ag leaching rate and the like exist. In addition, in the subsequent silicon purification process, glass phase/solid solution of Ag-Si interface can prevent leaching reagent from penetrating, even if ultrasonic assistance is adopted, ag is still leached completely for more than 6 hours and the efficiency is lower than 70%, the purity of Si after purification can only reach 85% -95%, and the high-value requirement is difficult to meet. Therefore, development of a new recovery technology for waste crystalline silicon photovoltaic modules is needed, which can not only efficiently recover metal resources, but also realize high-value reuse of silicon, and simultaneously reduce process energy consumption and environmental impact. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, the embodiment of the invention provides a method for recycling metal and silicon in a waste crystalline silicon photovoltaic module, which breaks material interface barriers through mechanochemical activation, strengthens metal leaching, combines an electric pulse driven carbon thermal shock process to realize rapid high-value conversion of silicon, and finally realizes low-loss and high-efficiency recycling and high-value reutilization of all components of metal and silicon resources in the waste crystalline silicon photovoltaic module. In order to achieve the aim of the invention, the invention adopts the following technical scheme: The embodiment of the invention provides a method for recycling metal and silicon in a waste crystalline silicon photovoltaic module, which comprises the following steps: (1) Disassembling the waste crystalline silicon photovoltaic module, and removing the aluminum alloy frame and the junction box to obtain a frameless module; (2) Carrying out pyrolysis treatment on the frameless component to obtain a crystalline silicon battery piece, and washing and drying the crystalline silicon battery piece to obtain a dry crystalline silicon battery piece; (3) Mechanically activating the dry crystalline silicon battery piece to obtain activated crystalline silicon battery powder; (4) Carrying out acid leaching treatment on the activated crystalline silicon battery powder, and filtering to obtain leaching liquid and silicon slag, wherein the leaching liquid contains Ag metal and Al metal