Electrostatic separators are not commonly used for the selective sorting of different sorts of metals contained in a granular mixture. However, the separation might be possible if their characteristics (density, conductivity, size…) are different enough. The aim of this article is to evaluate the feasibility of sorting tinned and bare copper strands (length: 2 to 5 mm; diameter: 0.8 to 1.6 mm) contained in granular electric cable wastes, using a roll-type electrostatic separator with three different high-voltage electrode configurations: plate, Sshaped and reverse S-shaped. Experimental design methodology is used to investigate the effects of three factors: highvoltage applied to the electrode system, inclination of the highvoltage electrode, inter-electrode distance. The recovery and purity of the bare copper product are evaluated for each experiment. The best results of the electrostatic separation experiments are obtained with the reversed S-shaped electrode configuration (recovery of 55.4% of the bare copper wire, in a product having a copper content of 85.1%). Numerical modelling and experimental visualization of particle trajectories facilitate the interpretation of the electrostatic separation experimental results. |
