Silver Recovery From End-of-Life Photovoltaic Panels

Abstract

<jats:p xml:lang="en">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.</jats:p>

A Comprehensive and Sustainable Recycling Process for Different Types of Blended End-of-Life Solar Panels: Leaching and Recovery of Valuable Base and Precious Metals and/or Elements

“…The goal of this step is the selective extraction of silver over other metals. Many researchers have found that HNO 3 shows good performance in the selective dissolution of silver over tin and lead [29,[76][77][78]. After leaching, the samples were filtered and dried; subsequently, leaching experiments were conducted with glycine.…”

Synthesis of Sulfur-Grafted Chitosan Biopolymers and Improvement to Their Sorption of Silver Ions from Different Aqueous Solutions

“…Some of its alloys, i.e., silver-copper, are used in computer manufacturing. Silver is used in high-tech industries (i.e., electrical connectors), electronics, products for health care, photovoltaics cell production [1,2], button cells [3], and several nanomaterial industries [4][5][6][7]. Silver is used in light reflection industries for mirrors and photographic films (and X-ray films) because of its sensitivity to light and in photochromic lens manufacturing [8].…”

“…It is noteworthy that there is a serious need to find a low-cost, effective and sustainable method for recovering silver (with a high efficiency) from leachates, wastewater, effluents, waste materials or other secondary resources. Several techniques have been used for reducing the silver concentration; i.e., electrodeposition methods have been used [1,17,18] and solvent extraction techniques have been used for recovering silver from highly concentrated solutions [19][20][21]. Extraction from low-grade solutions is performed through chelating composites [16,22], ion-exchange resins [23][24][25][26] and biosorbents [27][28][29].…”