Recovery of complete crystalline silicon cells from waste crystalline silicon photovoltaic modules

Firstly, the EVA adhesive film is dissolved with preheating treatment and ultrasonic-assisted toluene, and the backsheet are peeled off. The EVA film is then removed by thermal degradation. Finally, the high value but low reactivity silver (Ag) and aluminum (Al) are leached out with nitric acid (HNO₃). The hydrochloric acid (HCl) precipitation-ammonia (NH₃·H₂O) solubilization-hydrazine hydrate reduction process route was used to recover Ag. Addition of NH₃·H₂O to a leach solution containing only Al produces an aluminum hydroxide (Al(OH)₃) precipitate, which is then heat treated to produce aluminum trioxide (Al₂O₃). After the above process method, the recovery rate of complete crystalline silicon cells reaches more than 50%, the recovery rate of Ag reaches 95%, and the recovery rate of Al reaches 91%. The most important feature of this study is that the recovered intact crystalline silicon cells can be directly used in the reproduction of crystalline silicon PV module components. Implications: In this study "Recovery of complete crystalline silicon cells from waste crystalline silicon photovoltaic modules," a new process combining organic solvent method and thermal treatment method is provided with the main objective of efficient recovery of intact crystalline silicon cells. Finally, Ag and Al were efficiently recovered from crystalline silicon cells by chemical methods. The optimized process has the advantages of high integrity rate of recycled crystalline silicon cells, low recycling cost and low environmental pollution.<i>Implications</i>: In this study "Recovery of complete crystalline silicon cells from waste crystalline silicon photovoltaic modules," a new process combining organic solvent method and thermal treatment method is provided with the main objective of efficient recovery of intact crystalline silicon cells. Finally, Ag and Al were efficiently recovered from crystalline silicon cells by chemical methods. The optimized process has the advantages of high integrity rate of recycled crystalline silicon cells, low recycling cost and low environmental pollution.