CN-122013191-A - Environment-friendly recycling method for extracting copper, tin and lead from retired photovoltaic solder strip

Abstract

The invention discloses a deplating liquid and a green recycling method for extracting copper, tin and lead from a retired photovoltaic solder strip, wherein the deplating liquid comprises leaching liquid and a micro-nano bubble stabilizer; wherein the leaching solution comprises an organic acid solution, an acidic copper salt and an acidic ferric salt. The stripping solution has rich raw material sources, is more green and safer, and simultaneously is used for recycling copper, tin and lead from the retired photovoltaic solder strip, and has high recycling efficiency, low recycling cost and good economic benefit.

Inventors

• HAN WENSHENG
• WANG PENGCHENG
• DENG MEILING
• HU JIAQI
• YOU SHALI
• WAN CHAO
• Xie Manqian

Assignees

• 中国电器科学研究院股份有限公司

Dates

Publication Date

20260512

Application Date

20251215

Claims (10)

1. 1. A deplating solution for extracting copper, tin and lead from retired photovoltaic solder strips is characterized by comprising leaching solution and micro-nano bubble stabilizer, wherein the leaching solution comprises organic acid solution, acidic copper salt and acidic ferric salt.
2. 2. The stripping solution for extracting copper, tin and lead from retired photovoltaic solder strip according to claim 1, wherein the organic acid solution comprises at least one of methylsulfonic acid solution, sulfamic acid solution and acetic acid solution; optionally, in the deplating solution, the mass concentration of the organic acid solution is 20-100 g/L.
3. 3. The deplating solution for extracting copper, tin and lead from retired photovoltaic solder strip according to claim 1, wherein the acidic copper salt comprises at least one of copper acetate, copper methylsulfonate and copper sulfamate; Optionally, in the deplating solution, the mass concentration of the acidic copper salt is 15-150 g/L.
4. 4. The deplating solution for extracting copper, tin and lead from retired photovoltaic solder strip according to claim 1, wherein the acidic ferric salt comprises at least one of ferric sulfate, ferric citrate, ferric ammonium sulfate and ferric trichloride; optionally, in the stripping solution, the mass concentration of the acidic ferric salt is 20-200 g/L.
5. 5. The stripping solution for extracting copper, tin and lead from retired photovoltaic solder strip according to claim 1, wherein the micro-nano bubble stabilizer comprises at least one of octadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium chloride and dodecyl sodium sulfate; Optionally, in the stripping solution, the mass concentration of the micro-nano bubble stabilizer is 0.5-1 g/L.
6. 6. A green recycling method for extracting copper, tin and lead from retired photovoltaic solder strip by using the deplating solution according to any one of claims 1-5, comprising the following steps: (1) Pyrolyzing, physically crushing, sorting and cleaning the retired photovoltaic modules to obtain photovoltaic solder strips; (2) Immersing the photovoltaic solder strip in leaching solution for tin and lead removal to obtain copper wires and tin and lead removing solution, and cleaning the copper wires to obtain clean copper wires, wherein the leaching solution is the leaching solution in claim 1; (3) Adding sulfuric acid into the tin-lead removing solution obtained in the step (2) to generate lead sulfate precipitate, and carrying out solid-liquid separation to obtain lead sulfate precipitate and tin-containing solution; (4) Adjusting the pH value of the tin-containing solution obtained in the step (3) to 3-4, simultaneously adding a micro-nano bubble stabilizer into the tin-containing solution, performing heating treatment, then injecting micro-nano bubbles into the tin-containing solution to catalyze and oxidize Sn 2+ in the tin-containing solution into Sn 4+ , obtaining Sn (OH) 4 precipitate and filtrate after hydrolysis and filtration, and drying the precipitate to obtain SnO 2 powder; (5) Adding organic acid into the filtrate obtained in the step (4), injecting micro-nano bubbles to catalyze and oxidize Fe 2+ in the filtrate into Fe 3+ , realizing ferric iron regeneration, and finally adjusting the acidity of the filtrate to enable the filtrate to be circularly used for preparing the leaching solution.
7. 7. The green recycling method for extracting copper, tin and lead from retired photovoltaic solder strips according to claim 6, wherein in the step (1), the content of the tin-lead solderability coating on the surface of the photovoltaic solder strips is 3-5wt%, the tin-lead alloy component is Sn60/Pb40, and the thickness of the tin-lead coating is 2-5 μm.
8. 8. The green recycling method for extracting copper, tin and lead from retired photovoltaic solder strips according to claim 6, wherein in the step (2), the soaking temperature is room temperature, and the soaking time is 10-40 min.
9. 9. The green recycling method for extracting copper, tin and lead from retired photovoltaic solder strip according to claim 6, wherein in step (4), the temperature of the heating treatment is 50-90 ℃; And/or the time for catalytic oxidation of Sn 2+ to Sn 4+ is 10-60 min.
10. 10. The green recycling method for extracting copper, tin and lead from retired photovoltaic solder strips according to claim 6, wherein in the step (5), the time for catalytic oxidation of Fe 2+ to Fe 3+ is 10-30 min.

Description

Environment-friendly recycling method for extracting copper, tin and lead from retired photovoltaic solder strip Technical Field The invention belongs to the technical field of recycling of retired photovoltaic modules, and particularly relates to a deplating solution and a green recycling method for extracting copper, tin and lead from retired photovoltaic solder strips. Background Photovoltaic power generation has become the main body of new energy power generation technology in China, large-scale use of photovoltaic products leads to the generation of a large number of retired waste photovoltaic modules, the service life of the photovoltaic modules is 20-25 years, at present, the first generation of domestic photovoltaic modules enter a scrapping period, and according to the prediction, the photovoltaic modules in 2025 and 2030 reach 105 ten thousand tons and 1000 ten thousand tons respectively, and the photovoltaic modules become the fastest growing electronic waste in the world. If the waste components are improperly disposed, heavy metal harmful substances such as lead, copper, tin solder and the like may infiltrate into soil and water to cause environmental pollution, and meanwhile, high-value metal components are important renewable resources, and the improper disposal also causes resource waste. The photovoltaic solder strip is also called tinned copper strip or tin-coated copper strip, is an important component part of a photovoltaic module (shown in figure 1), is formed by a copper base material and a tin-lead alloy (Sn 60/Pb 40) surface coating, has higher recycling value, and the traditional tin stripping process mainly comprises etching of PCB circuit board pattern electroplated tin, mainly adopts a nitric acid system comprising high-concentration nitric acid and ferric nitrate to strip tin, the concentration of nitric acid is generally 20-25%, the stripping agent is complex in component, the preparation is troublesome, nitric acid is decomposed to generate a large amount of nitrogen oxide gas during stripping, the environmental pollution is serious, and the other mode adopts a sulfuric acid-hydrogen peroxide process to strip tin. The Chinese patent (CN 117385163A) adopts acid-washing tin stripping liquid to remove tin plating on waste circuit boards, the acid-washing tin stripping liquid takes high-concentration sulfuric acid and fluoboric acid as main agents, copper nitrate, copper sulfate, cuprous chloride and the like are added as tin stripping auxiliary agents, and the fluoboric acid contained in the acid-washing tin stripping liquid has strong toxicity, great harm to operators, great environmental pollution and difficult waste liquid treatment, and belongs to chemicals controlled by China my father. The electrolytic solution containing nitric acid, sulfuric acid, methanesulfonic acid and sulfamic acid is adopted in Chinese patent No. (CN 110760922A) to remove tin coating on the substrate, and nitric acid is reduced into nitrogen oxides such as NO 2、NO、NOX during electrolysis to generate a large amount of toxic and harmful gases, and simultaneously generate electrolytic wastewater containing ammonia nitrogen, which has great harm to the environment. Chinese patent (CN 110684904A) provides a method for recovering copper and tin from waste tin-plated copper wires, which comprises the steps of dispersing and immersing the waste tin-plated copper wires into copper sulfate or mixed solution of copper chloride and hydrochloric acid with lower concentration, leaching tin on the copper wires to obtain crude copper wires and tin stripping liquid containing bottom mud, and separating to obtain metal copper wires and tin dioxide powder. The method adopts low-concentration copper sulfate or copper chloride and hydrochloric acid mixed solution to remove tin, and has the defects that tin dissolved by the displacement reaction of metallic tin and soluble copper salt is only a very thin part of a tin plating layer on the surface, the displacement reaction is stopped because the metallic copper generated by displacement is wrapped on the outer surface of the tin plating layer, the tin plating layer with certain process thickness cannot be completely removed in practice, the separation of tin and copper is incomplete, the low-concentration copper salt also causes lower actual removing efficiency, and the method does not particularly show how to completely precipitate tin ions in tin removing liquid, and meanwhile, the tin-lead alloy plating layer is difficult to remove by the process because of the indissolvable lead sulfate and lead chloride. Therefore, development of a retired photovoltaic solder strip recycling process with high copper, tin and lead separation and extraction efficiency and environmental protection is needed, the defects of the existing process are overcome, and the recycling efficiency of metal resources is improved. Disclosure of Invention The present invention aims to solve at least o