SILVER RECOVERY FROM END-OF-LIFE PHOTOVOLTAIC PANELS

Abstract

The growth of the photovoltaic sector has stood out among renewable sources of energy, due to technological innovations that have brought about cost reductions. Thus, this paper aimed to analyze the technical feasibility of silver recovery from photovoltaic cells using acid leaching, followed by an evaluation of the chemical and electrochemical precipitation processes to analyze their efficiencies. As a primary objective of this work, the gravimetric composition and the metal concentration (Ag, Al, Pb, Cu, and Fe) in the photovoltaic cells were first determined, developing the basis for future research on photovoltaic panels recycling Subsequently, the influence of HNO3 concentration (1-10 mol/L), temperature (25-60ºC), and reaction time were evaluated. A new research application used a statistical tool, the Central Composite Rotational Design (CCRD), as well as samples of different brands and models of photovoltaic panels, in order to ensure the experimental validity. As a highlight, the analysis of the composition of the photovoltaic cells, applying the HNO2CO3, as well as electroprecipitation, made it possible to extract more than 99% of silver in solution, being a primary novelty of this study. Therefore, the studied pathway allowed for the recovery of 99.98% of the silver present in the photovoltaic cells.