Recycling Copper (Cu) from Waste Automotive Printed Circuit Boards (WPCBs) After Characterization and Liberation Study by Mineral Processing Techniques

Waste printed circuit boards (WPCBs) are one of the fastest-growing waste streams and pose a significant environmental challenge while also representing a valuable secondary resource due to their rich metal content, particularly copper (Cu). Since effective recovery of metals requires mechanical pre-treatment and advanced characterization, WPCB boards were subjected to size reduction and then characterized through X-ray fluorescence (XRF), inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscopy (SEM-EDS), and mineral liberation analysis (MLA). Results indicated that copper is predominantly found in coarser particle sizes due to its ductility, while glass fibers and ceramics dominate finer fractions. Liberation studies revealed that Cu is essentially free in fine particles (<100 μm) but tends to remain locked in coarser fractions. Based on these results, gravity separation methods were employed to concentrate the copper: coarse particles (>300 μm) were treated on a shaking table, achieving a Cu recovery of 95%, while fine particles (<300 μm) were processed using a multi-gravity separator (MGS), with recoveries of 94% for 100 × 300 μm and 81.5% for <100 μm size fractions. This study presents a gravity-based separation strategy that combines shaking tables and MGS to optimize Cu recovery from automotive WPCBs. To the authors’ knowledge, the MGS application for WPCBs has received little attention, despite its strong potential for separating this type of waste. The proposed methodology enhances the concentration and purity of the metallic fraction (in this case, Cu), especially in fine particles, which are challenging to work with, while reducing environmental impacts through minimal chemical use, thereby contributing to sustainable e-waste recycling.