From e-waste to resource: Identifying the optimal pre-treatment for copper recovery from waste PCBs

The effective recovery of copper from waste printed circuit boards (WPCBs) is crucial for promoting circularity in the electronic sector and mitigating resource loss. This study identifies and evaluates thirteen pre-treatment methods—classified as mechanical, thermal, chemical, and innovative—using 23 technical, environmental, and economic indicators. A multi-criteria decision analysis (based on the Technique for Order of Preference by Similarity to Ideal Solutions, TOPSIS) was applied under four weighting scenarios to reflect different prioritisation strategies. Results show that automated disassembly consistently ranks highest when technical and environmental performance is prioritised, while manual dismantling prevails under cost-sensitive conditions. Sensitivity analysis confirms the robustness of these rankings, highlighting trade-offs between efficiency, environmental impact, and economic feasibility. Although still mostly at the laboratory scale, automated disassembly shows strong potential for efficient, low-impact copper recovery, and scaling with artificial intelligence (AI) and robotics could drive sustainable e-waste management and ease copper supply constraints.