Recovery of copper and valuable metals from E-waste via hydrometallurgical method

Abstract

Hydrometallurgical processes such as sulphuric acid leaching for recovering metal from waste from electrical and electronic equipment (WEEE), especially metal-rich printed circuit board (PCB), have provided a route for WEEE recycling. This study investigated the effect of the rate of oxidants (hydrogen peroxide) addition in volume per hour and temperature on the extraction of copper and other valuable metals from waste printed circuit board (WPCB). The optimum condition for the extraction of copper and valuable metal in sulphuric acid leaching were determined. The crushed and ground WPSB were leached in the sulphuric acid solution using hydrogen peroxide as an oxidant. The influence of two parameters; temperature (30 °C and 75 °C) and rate of oxidant addition (20 ml/hr and 60 ml/hr) were investigated against the extraction of copper (Cu, 30 wt%), aluminium (Al, 10.5 wt%), iron (Fe, 2.4 wt%), and zinc (Zn, 0.2 wt%). Scanning electron microscope-backscattered electron (SEM-BSE) image shows that shredding PCB into sizes smaller than 2.00 mm is sufficient to expose laminated copper components for an efficient sulphuric acid leaching process. The optimal condition for high extraction of copper was 1.5 M sulphuric acid, with 30 % hydrogen peroxide at rate 60 ml/hr, for ∼ 10 g of PCBs powder with a solid–liquid ratio of 1:10 for 1 h at temperature 75 °C.High percentage of extraction has been achieved in sulphuric acid media within 1 h (Cu (98 %), Al (52 %), Fe (52 %), Zn (92 %).