Influence of high-voltage electrode shape on granular metal particle trajectories in a roll-type electrostatic separator

Electrostatic separation is widely recognized as an efficient and reliable WEEE recycling method, offering several advantages such as low energy consumption, reduced operational cost, and relatively simple implementation. Nevertheless, this process remains inherently complex due to its strong dependence on multiple operational parameters. Therefore, careful selection of electrical and geometrical configurations is essential to ensure effective treatment of material mixtures and achieve optimal separation performance. In this context, the present study investigates the influence of the direct current high voltage (HVDC) applied to the high-voltage (HV) electrode, along with the electrode’s geometric shape, on the trajectories of metallic particles in a roll-type electrostatic separator. To this end, the particle trajectories were analyzed using an ultra-high-speed camera. This visualization method proved to be both relevant and innovative for optimizing electrode design. The results indicate that both the geometric profile of the HV electrode and the applied voltage significantly affect the particle trajectories. Notably, the use of an inverted S-shaped electrode allowed for better trajectory control compared to elliptical and flat electrode configurations.