Recovery of copper and lead from waste printed circuit boards by supercritical water oxidation combined with electrokinetic process

Abstract

a b s t r a c tAn effective and benign process for copper and lead recovery from waste printed circuit boards (PCBs) was developed. In the process, the PCBs was pre-treated in supercritical water, then subjected to electrokinetic (EK) process. Experimental results showed that supercritical water oxidation (SCWO) process was strong enough to decompose the organic compounds of PCBs, and XRD spectra indicated that copper and lead were oxidized into CuO, Cu 2 O and ␤-PbO 2 in the process. The optimum SCWO treatment conditions were 60 min, 713 K, 30 MPa, and EK treatment time, constant current density were 11 h, 20 mA cm −2 , respectively. The recovery percentages of copper and lead under optimum SCWO + EK treatment conditions were around 84.2% and 89.4%, respectively. In the optimized EK treatment, 74% of Cu was recovered as a deposit on the cathode with a purity of 97.6%, while Pb was recovered as concentrated solutions in either anode (23.1%) or cathode (66.3%) compartments but little was deposited on the electrodes. It is believed that the process is effective and practical for Cu and Pb recovery from waste electric and electronic equipments.

Preparation of nano-Cu2O/TiO2 photocatalyst from waste printed circuit boards by electrokinetic process

“…Experimental conditions were 713 K, 25 MPa and 1 h, respectively. Most of the BFR in the waste PCBs could be removed and Cu could be oxidized completely at such conditions according to previous reports [9,12].…”

“…Metals could be leached and migrate to cathode or anode compartment, then recovered by reducing to form a deposit on the cathode or by other methods. In our previous study [12,13], a process combined SCWO and EK techniques was developed for the treatment of waste PCBs. Cu was recovered as a deposit on the cathode [12] and other heavy metals were recovered as concentrated solutions in anode or cathode compartment of EK system [13].…”

“…However, all of the processes above-mentioned can only recover the metallic material of copper [6][7][8]12]. There will have good prospects for direct preparing high value-added functional materials from waste PCBs.…”

Preparation of BaPbO3 functional ceramics from leaded waste

“…The anode slime from printed circuit boards (PCB) waste recycled by copper electrolysis contains many valuable metals, including a lot of Pb and Sn, and some noble metals (Au, Ag, Pt, Pd, etc.). It is particularly important that the Pb content could be up to 20 wt% in the form of PbSO 4 . Consequently, the leaded waste of anode slime from PCB waste is an important secondary lead resource and can lead to serious environmental pollution without being recycled.…”

“…There are several investigations on recycling Pb from different kinds of leaded waste [4][5][6]. Currently, the main technical process of extracting Pb from PCB waste is pyrometallurgical technology.…”