Copper Extraction from Flue Dust of Electronic Waste by Electrowinning and Ion Exchange Process

Abstract

The recovery of valuable metals from electronic waste has attracted a great deal of attention recently in the field of recycling. The recovery process for metal resources present within flue dust from e-waste to obtain valuable metals, such as Cu, by both physiochemical and electrical processes has been investigated. The flue dust was generated during the smelting process of e-waste and contained metals such as Cu, Al, and Fe. When considering the acid leaching efficiency and pulp density of Cu, 50 g/L pulp density and 1 M H2SO4 at 60°C for 4 h were selected for Cu recovery. Electrowinning and ion exchange methods were also applied to extract Cu from a leachate. In the electrowinning experiment, about 94% of Cu was obtained at current density of 15 mA/cm2 for 3 h. Two methods were applied for ion exchange experiments: a static method using a chromatography column, and a dynamic method using a magnetic stirrer and impeller. The amount of Cu that can be recovered by 1 g of resin, namely the adsorption capacity qt, was also measured. However, since ion exchange by cation resin in the leachate recovered not only Cu but also Fe and Al, the extraction efficiency of Cu was less than that obtained when using pure CuSO4 solution. Based on these results, a study was conducted to combine electrowinning and ion exchange for recovery of valuable metals, purification of the acid solution, and ultimately, reuse.