Silver Recovery from e-Waste Printed Circuit Board Using Biner and Terner Deep Eutectic Solvent
Soja Siti Fatimah (a*), Omay Sumarna(a), Abraham Mora(a), Arrizal Abdul Aziz(a)

a)Chemistry Studi Program, Faculty of Matethematic and Science Education

Abstract

This research aims to optimize the extraction of silver metal from Printed Circuit Board (PCB) waste using Deep Eutectic Solvent (DES) based on choline chloride and glycerol (glycerin DES), and compare it with DES based on choline chloride, glycerol, and citric acid (ternary DES). This research method adopts a solvometallurgical approach with leaching process as the main focus to obtain maximum silver metal extracts. Instruments used in this research include Fourier Transform Infrared Spectroscopy (FTIR) to analyze the bond interactions formed in DES and X-Ray Fluorescence spectrometry (XRF) to determine the percentage of metals before and after leaching. The characterization results reveal that the silver metal content in PCB is 2.32%, and there is broadening and shifting of the peak spectrum in DES indicating the formation of new intermolecular interactions, namely C-OH···Cl interaction. The leaching process of silver metal from PCB using glycerin DES is optimized by considering the effects of leaching time and solid-liquid (S/L) ratio. The optimization results indicate the optimal leaching time is 16 hours with a silver metal extract of 56.80%. The optimal S/L ratio is 1/20 resulting in a silver extract of 86.77%. The use of DES terner yields a silver extract of 93.65%, surpassing glycerin DES. The more acidic DES terner enhances proton activity and accelerates chemical reaction kinetics, making it more effective in leaching silver metal from PCB waste. The use of DES terner demonstrates potential as an effective method for leaching silver metal from PCB waste samples, offering a sustainable solution for electronic waste processing.

Keywords: electronic waste, PCB, silver metal, DES, leaching, optimization

Topic: Chemistry