Improved leaching of Cu, Sn, Pb, Zn, and Al from waste printed circuit boards by electro-generated Cl2 in HCl solution

Jian Zhao; Zunzhang Liu; Chunlin He; Yingnan Yang; Jie Li; Toyohisa Fujita; Guiwang Wang; Fang Shen

doi:10.1016/j.wasman.2022.09.022

Improved leaching of Cu, Sn, Pb, Zn, and Al from waste printed circuit boards by electro-generated Cl₂ in HCl solution

Waste Manag. 2022 Nov:153:386-396. doi: 10.1016/j.wasman.2022.09.022. Epub 2022 Oct 2.

Authors

Jian Zhao¹, Zunzhang Liu¹, Chunlin He², Yingnan Yang¹, Jie Li¹, Toyohisa Fujita³, Guiwang Wang⁴, Fang Shen⁵

Affiliations

¹ School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
² School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials, Nanning 530004, China. Electronic address: helink1900@126.com.
³ School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials, Nanning 530004, China. Electronic address: fujitatoyohisa@gxu.edu.cn.
⁴ School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials, Nanning 530004, China.
⁵ College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.

PMID: 36198214
DOI: 10.1016/j.wasman.2022.09.022

Abstract

This paper investigated the improved leaching of Cu, Sn, Pb, Zn, and Al from waste printed circuit boards (WPCBs) by electro-generated Cl₂ in HCl solution through multiple leaching cells in series, double intake pipes, and bubble stone for leaching. The leaching agents in the leaching cell include Cl₂(aq), HCl, HClO, and Cl₃^-. The leaching rate and leaching speed of Zn, Sn, Al, and Pb exceeded that of Cu. Leaching time and HCl concentration have a strong impact on the dissolution of Cu, whereas the effect of the electrolytic current and the leaching temperature is comparably weak. The series of leaching cells improved the effective utilization of Cl₂ and increased the treatment capacity of the WPCBs. Bubble stones significantly enhanced the efficiency and rate of leaching. Reduction of the size of the Cl₂ gas bubbles improved the leaching kinetics. The leaching rate of Cu reached 87.22%, whereas the leaching rate of Zn, Sn, Al, and Pb exceeded 90% after 100 min. Our experimental data provide a reference for electrolytic leaching recovery of metals from WPCBs, and our method improves the metal leaching and electrolytic efficiency in practice.

Keywords: Cl(2) gas bubbles; Copper leaching; Electro-generated chlorine; WPCBs.

MeSH terms

Copper
Electronic Waste* / analysis
Kinetics
Lead
Zinc

Substances

Lead
Copper
Zinc