Electrostatic Separation Methods for Metal Removal from ABS Wastes

The electrostatic separation techniques have been widely used in the recycling industry. The aim of the present work is to assess the possibility of employing them for the beneficiation of the newest and fastest growing category of wastes: the "end-of-life" information technology equipment. The study was performed on samples extracted from a granular ABS product obtained after disassembling and shredding of IT wastes. The samples, that typically contained less than 0.1% metals in weight, were processed in a laboratory electrostatic separator that enabled the reproduction of the two most important electrode configurations employed in industry. The design of experiments methodology was employed for evaluating the effects of the various electrical and mechanical control variables on the outcome of the separation process. The reported data demonstrate that by appropriate adjustment of the input variables of either a plate-type electrostatic separator or a roll- type corona-electrostatic installation, it is possible to remove all the metallic particles from the ABS product, while keeping at a minimum the quantity of plastics lost in the rejected conductive fraction.