Recovery of high-grade copper from metal-rich particles of waste printed circuit boards by ball milling and sieving

ABSTRACT

In this paper, a method of ball milling and sieving is proposed for recovery of high-grade copper from waste printed circuit boards (WPCBs). The effects of the milling time on the metals grade and recovery of the Cu, Sn and Pb during mechanical treatment were investigated. The results showed that, after 3 cycles of ball milling and sieving, the content of Cu was enriched to 94.72 wt.% from the initial 74.22 wt.% with a high recovery rate of 86.78%. Moreover, the contents of Sn and Pb were enriched to 28.27 wt.% and 18.86 wt.% from 10.13 wt.% and 6.63 wt.% in the by-products, respectively. However, excessive grinding occurred when the milling time was longer than 3 h and led to a sharp decrease in Cu recovery. The X-ray diffraction (XRD) patterns indicated that the metal phases mainly comprised pure Cu, Sn, Pb in the WPCB particles, while a Cu-Sn alloy was formed during the milling process, and the Cu-Sn alloy was also enriched in the tailings. The results presented here establish that ball milling and sieving is an alternative approach to recovering high-grade copper from WPCBs.

GRAPHICAL ABSTRACT

KEYWORDS:

• Recovery
• Cu
• waste printed circuit boards
• ball milling
• sieving

Acknowledgement

The authors would like to acknowledge the financial support given by the Scientific Research Project of Guangdong University of Science and Technology (No. GKY-2019KYZD-1), Major Scientific Research Program of Higher Education of Guangdong (No. 2019KTSCX254), and Guangdong Basic and Applied Basic Research Foundation (No. 2019A1515110726).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors would like to acknowledge the financial support given by the Scientific Research Project of Guangdong University of Science and Technology [grant number GKY-2019KYZD-1], Major Scientific Research Program of Higher Education of Guangdong [grant number 2019KTSCX254], and Guangdong Basic and Applied Basic Research Foundation [grant number 2019A1515110726].