Operational conditions of an electrostatic separator for concentrate copper from electronic waste

Abstract

Interest in recycling for the recovery of valuable substances, such as precious metals from electric and electronic waste has been increasing year after year due to the large amount present in such waste compared to primary sources. There is environmental concern, since the amount of this kind of waste is increasing due to rapid technological advances. This study aimed to test the different operating conditions of an electrostatic separator for the concentration of copper from printer circuit boards (PCB). The PCBs were milled in knife mills and separated according to the difference of granule sizes into two fractions: A (<0.5 mm); B (0.5<B<1 mm), followed by scaling. Then, the samples were subjected to a magnetic separator for removing the magnetic materials to obtain a concentrate with a higher content of copper. After the magnetic separator, an electrostatic separator was used, where different conditions were employed for each sample: roller rotation (100 and 175 rpm) and tension (20 and 35 kV). Iron concentrations were observed after the magnetic separator, between 12 and 14.1% for the A fractions and 10.3–11.4% for the B fractions. After the electrostatic separator, the results for the A samples showed that the concentration of copper varies between 17.5 and 51.1%, with the highest concentration obtained through the use of 100 rpm (roller rotation) and 35 kV (voltage). For the B samples, the variation was between 6.4 and 40.5 %. For both particle sizes, the best applied condition was a voltage of 35 kV and a roller rotation of 100 rpm.