Recycling of printed circuit boards by abrasive waterjet cutting

The rapid growth of waste printed circuit boards (PCBs) necessitates development of compatible treatment techniques. In this study, abrasive waterjet (AWJ) cutting technology was utilized to crush waste PCBs for the first time. Cutting experiments were mainly performed on waste mobile mainboard, random access memory (RAM), universal circuit board (UCB), and central processing unit (CPU). The results demonstrated that AWJ cutting was capable of breaking waste UCB (similar to 14 mm thick) into small particles (< 1 mm) in one-step processing, by which metals and nonmetals were well dissociated. SEM images of RAM and mainboard showed PCBs had a multi-layer structure, which would favor component dissociation under the mechanism of abrasive grinding. All the cutting debris of CPU (mainly Cu and Ti particles) were micro-sized (< 150 mu m) and metals were completely dissociated. Mechanical property analysis showed tensile strengths of RAM, UCB, and CPU were 150.0, 72.3 and 74.4 Mpa, respectively, which were apparently lower than that of hard materials. This implied that AWJ cutting has a huge potential in enhancement of material-removal indicator through system improvement and process optimization. Thus, this study offers a promising environmental-friendly method for recovering metal resources from e-waste. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.