A comprehensive review of the mechanical separation of waste printed circuit boards

Abstract

The rapid proliferation of electronic devices has led to the accumulation of substantial Electronic waste (Ewaste), comprising valuable metals and hazardous components. Therefore, e-waste recycling through mechanical separation combining several physical and physio-chemical separation processes has emerged as a pivotal approach to address the escalating challenge of electronic waste management. The present article overviews the mechanical separation techniques employed in recycling waste Printed Circuit Boards (PCBs), a significant component of all electronic devices, to recover valuable metals. Various separation methods such as comminution, air classification, froth flotation, gravity separation, magnetic separation, and electrostatic separation are discussed in the context of their application for e-waste processing. The efficiency of these processes in segregating metallic components, including critical, precious, and base metals, from non-metallic fractions is reviewed. Overall, the article shows the importance of the mechanical separation processes as a viable route for extracting valuable resources from e-waste while minimizing the environmental impact of improper disposal.