Copper/silver recovery from photovoltaic panel sheet by electrical dismantling method

The volume of spent photovoltaic (PV) panels is expected to grow exponentially in future decades. Substantial material resources such as silver (Ag), copper (Cu), aluminum (Al), silicon (Si), and glass can potentially be recovered from silicon-based PV panels. In this paper, we targeted the recovery of Cu and Ag from a cell sheet separated to a glass panel from a spent PV panel. The technical feasibility of a novel electrical dismantling method was experimentally studied. This method employed a pulsed power technology that re-leases high energy in a short time. It allowed a selective separation of the Cu/Ag wires from the sheet once per discharge in water. The experimental results indicated that 95.6% of the total Cu and 17.2% of the total Ag in the sample were successfully separated from the cell sheet using a 3.5-kJ capacitor bank circuit. More-over, 3.66% of the total Si in the sample was contaminated by the separated Cu/Ag particles from the cell sheet, mainly by shockwaves generated by plasma expansion, and some of them formed a compound with Cu and Ag by eutectic melting, resulting in low liberation. At the lower energy of 3.5 kJ, eutectic melting of Cu and Ag with Si was more suppressed than 4.6 kJ, and 94.3% of Cu and 77.5% of Ag in the separated particles were liberated, which would be acceptable for further wet gravity and/or shape separation of Cu and Ag.