Prior electro-mechanical separation to improve metal recovery from ceramic-rich electronic waste using bioleaching

PCBs, as one of the most valuable streams of e-waste, are a considerable source of precious metals, but also contain considerable amounts of plastic and ceramic. These non-metallic fractions interfere with and can inhibit the efficiency of metal recovery, particularly for precious and rare earth metals, which are present in e-waste in very low concentrations. In this work, electro-mechanical pre-treatment was applied in order to remove ceramic and plastic fractions from e-waste prior to the application of the bioleaching process. Metal content with and without mechanical separation, as well as metal dissolution and behaviour in the bioleaching process were compared. The results obtained illustrate the beneficial effects of separating the metallic from the non-metallic fraction prior the bioleaching process for the recovery of precious, rare earth and base metals from e-waste.