Optimisation of belt-type electrostatic separation of tribo-aerodynamically charged granular plastic mixtures

摘要

The electrostatic separation is frequently employed for the selective sorting of conducting and insulating materials for waste electric and electronic equipments (WEEE). In a series of recent papers, the authors have presented several novel tribo-electrostatic separation installations for the recycling of the main categories of plastics contained in information technology wastes. The aim of the present work is to optimize the design and the operation of such an installation, composed of a belt-type electrostatic separator associated to a propeller-type tribo-charging device. The experimental design method is employed for modeling and optimizing the separation of a mixture of high-impact- polystyrene (HIPS) and acryl-butyl-styrene (ABS) granules originating from shredded out-of-use computer cases. A distinct experiment is carried out on three synthetic mixtures of virgin plastic granules: 75% polyamide (PA) + 25% polycarbonate (PC); 50% PA + 50% PC; 25% PA + 75% PC. The best results are obtained for the mixtures containing equal quantities of the two constituents.