Separation of Cu, Sn, Pb from photovoltaic ribbon by hydrochloric acid leaching with stannic ion followed by solvent extraction

Abstract

A recycling process consisting of HCl leaching with Sn4+ followed by solvent extraction is proposed to recover Cu, Sn and Pb from photovoltaic (PV) ribbon. During HCl leaching with Sn4+, Sn and Pb were removed from PV ribbon whereas Cu remained as plate. The leaching efficiency of Sn increased with increasing temperature, initial Sn4+ concentration or decreasing pulp density. In the case of leaching test performed in the 1M HCl solution at 400rpm and 70°C with 5% pulp density and 5000mg/L Sn4+, the leaching efficiency of Sn increased to >99% within 60min, whereas 71.9% of Pb was recovered as PbCl2 powder after settling the leach solution for 24h at room temperature. A solvent extraction with tri-butyl phosphate (TBP) was performed to extract selectively Sn from leach solution. The extraction efficiency of Sn increased with increasing the contents of TBP in kerosene, and <1% of Pb was extracted. Therefore, the separation of Sn, Cu, Pb was achieved successfully by the recycling process.