Recovery of valuable metal from Photovoltaic solar cells through extraction

Abstract

The installation of PV modules was 97.9GW and the accumulation volume of PV device was 500GW in 2018 According to the research, the accumulation of waste modules will reach to 8600 tons in 2030 as the result of the life expectancy of PV modules. Moreover, Crystalline-Silicon solar panels account for 90% of the waste. This study recycles photovoltaic solar cells by leaching and extraction. According to the analyst, Silicon cells content 90% of Si, 0.7% of Ag, and 9.3% of Al. Silicon cells were leached by 4M nitric acid at 80°C for 4 hours then 3M sodium hydroxide at 70°C for 3 hours, and the leaching efficiency were 99.7% of Ag, and 99.9% of Al, respectively. Leaching process separated Silicon from others metal. Na-Cyanex 272 in kerosene was employed to separate Al from Ag. The efficiency of extraction is 96%. After the process of extraction, 1M hydrochloride acid was employed to strip Al from the organic solvent. The efficiency of stripping is 99.9%. After extraction process, Ag was remained in the aqueous phase and precipitated to AgCl. In conclusion, this study shows the optimal parameters of the leaching steps, extraction steps, precipitation and vaccum concentration to get the product. The recovery of Si and Ag were 99.5% and 98% respectively.