Recovery of valuable materials from the waste crystalline-silicon photovoltaic cell and ribbon

Abstract

With the dramatic increase of photovoltaic (PV) module installation in solar energy-based industries, the methods for recovering waste solar generators should be emphasized as the backup of the PV market for environmental protection. Crystalline-silicon accounts for most of the worldwide PV market and it contains valuable materials such as high purity of silicon (Si), silver (Ag), copper (Cu), tin (Sn), and lead (Pb). This study can provide an efficient recycling process for valuable materials resourced from waste crystalline-silicon PV module, including Si in the PV cell, and Ag, Cu, Pb, Sn, in PV ribbon. As tempered glass and Ethylene Vinyl Acetate (EVA) resin were removed, the module was separated into two materials, PV ribbon and PV cell. For PV cell purification, Si with purity at 99.84% was recovered by removing impurities such as aluminum (Al) and Ag by two-step leaching and dissolving the impurities. For PV ribbon recovering, purified metal or metal oxide was obtained through the processes of leaching/polishing, extraction, and chemical precipitation. In the polishing process, 99.5% of copper wire was collected. The purities of final products are 99.7% for CuO, 99.47% for PbO, 99.68% for SnO2, and 98.85% for Ag respectively.