New and facile recovery strategy for silver, copper, and nickel from waste silver contacts using polyiodide ionic liquids

Abstract

This work proposed a novel strategy for recovering Ag, Cu, and Ni from waste silver contacts (WSCs) using polyiodide ionic liquids (ILs). Our method exhibited exceptional leaching efficiency (Ag: 98.7%, Cu: 99.1%) and remarkable reusability (over 6 cycles). In contrast to a traditional three‐step leaching‐extraction‐striping process, our polyiodide ILs present a significant simplification. This approach is ideal for practical applications due to its low viscosity (49.6 cP) and gentle (55°C) leaching conditions of polyiodide ILs. Additionally, the redox leaching mechanism was successfully elucidated by XPS, XRD, and UV‐vis spectra. Based on our findings, a closed‐loop route for the recovery and separation of Ag, Cu, and Ni was suggested. Moreover, economic analysis revealed that the recovery of 1.0 kg WSCs could generate a considerable profit of 58 ± 7 USD. Overall, this new method provides a rapid, high profit, and sustainable recovery strategy with significant potential for industrial applications.