Recovery of valuable and toxic metals from crystalline-Si modules
Valuable and toxic metals including Ag, Pb, Sn and Cu can be recovered from end-of-life Si solar modules. This study presents the recovery of Ag, Pb, Sn and Cu from a simulated leach solution of crystalline-Si modules. 11.4% HNO3 is used as the leach solution. Ag, Pb, Sn and Cu pellets are dissolved in the solution to simulate the metals from front contacts and soldered wires in Si modules. Sn precipitates in the solution as SnO2, which can be separated by filtration or sedimentation. Voltammetry reveals the reduction potentials for Ag and Cu. It is demonstrated that 3-electrode sequential electrowinning can extract Ag and Cu one by one from the solution. The recovery rates of Ag and Cu are 74% and 83%, respectively. Toxic Pb is deposited on the anode as PbO2 during Cu recovery. The purity of the extracted metals is above 99%.
Chemical treatment of crystalline silicon solar cells as a method of recovering pure silicon from photovoltaic modules
Photovoltaic technology is used worldwide to provide reliable and cost-effective electricity for industrial, commercial, residential and community applications. The average lifetime of PV modules can be expected to be more than 25 years. The disposal of PV systems will become a problem in view of the continually increasing production of PV modules. These can be recycled for about the same cost as their disposal.
SR topography of plastically deformed Fe-Si bicrystals - observation in situ and post mortem
SR reflection topography was applied to study the interaction of slip dislocations with the grain boundaries in Fe-4at%Si bicrystals deformed by compression. Three experimental settings with either a white or monochromatic beam were used and the corresponding orientation contrast analysed. Dislocation transmission through the grain boundary was observed in bicrystals with favourable geometry of the slip systems.