Improving particle separation and recovery of valuable materials from end-of-life solar panels

Massive photovoltaic (PV) modules will be decommissioned and must be properly recycled, but the current methods cannot recycle end-of-life PV panels especially recovering valuable materials like silver and silicon in a feasible way. In this study, a highly efficient recycling method is developed, featuring a novel sieving aids technology for high-efficiency separation of solar cells and glass, connected with the upstream pyrolysis for delamination and downstream chemical leaching for silver recovery. The results indicate that over 96.3 wt.% of the chip-like PV cell particles can be separated from the debris mixture under the optimised sieving conditions using the new sieving aids technology, compared to the separation rate of 31.7% in the conventional sieving methods. The PV cell particles collected by the separation process are further leached by the 4M nitric acid at 40°C for 30 mins in a beaker for silver extraction. The leaching result shows that over 98.9% of the silver contained in the PV modules can be recovered by this integrated method. The study provides a new method for a highly efficient recycling process of end-of-life PV modules.