Co-recovery of Ag and Si from PV cell panels: Directional solidification assisted by PV glass

• Published in: Separation and purification technology Vol. 353; p. 128428
• Main Authors: Li, Jiayan, Li, Yaoyao, Yu, Fengyun, Hu, Zhiqiang, Gao, Qihe, Li, Pengting, Tan, Yi, Jiang, Dachuan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 19.01.2025
• Subjects: Co-recovery of Ag and Si; Directional solidification; Photovoltaic waste; Slag refining; Slag refining; Co-recovery of Ag and Si; Directional solidification; Photovoltaic waste
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2024.128428

•An approach that enable recycling PV Cell panels was proposed.•Photovoltaic waste glass successfully used as slagging agent.•Effectively inhibit the early precipitation of high value metals.•High-value element enriched areas narrowed to 2.9 %.•Ingot purity up to 4N after purification. In the current context, a significant accumulation of photovoltaic (PV) waste poses a challenge without an efficient method for recovering high-value metal materials, such as silver (Ag). This study aimed at to solve the problem of low yield caused by premature precipitation of high-value elements in the traditional pyrometallurgical recovery processes. By using PV waste glass as an additive, the migration of elements and crystal growth process during directional solidification are optimized. Then, through the slag effect, the Al element in the PV cells was separated, effectively suppressing the grain instability caused by Al element enrichment. Furthermore, the addition of PV glass can effectively improve the thermal field distribution at the front of the Solid-Liquid (S/L) interface during the solidification process, promote the stable advancement of the interface, and further promote the enrichment of Ag towards to the top. Ultimately, nearly all the Ag is concentrated in the top area of the obtained ingot, reducing the zone proportion to 2.9%, and at this point, the purity of primary silicon reached 99.99%, significantly enhancing the recovery rate. This study establishes that the addition of PV glass has a noteworthy positive effect on the separation and recovery of Ag and Si, offering a promising approach for recycling within the PV industry.