A new trend of physical concentration in resources recycling

Physical separation is one of the key technologies in the field of resources recycling for concentrating targeted component(s) and could create an environment friendly recycling process because of their relatively low energy consumption and low cost required. Physical separation process involves two kinds of stages, one is comminution for achieving the liberation of targeted component(s) and the other is real separation of target component(s) from the others. Recently a variety of smart comminution processes, involving mechanical and electrical disintegration as well as the pre-treatment, is developed for aiming selective breakage of phase boundaries of the solid materials to be recycled. The paper indicated several examples of such processes, (1) selective mechanical comminution for effective utilization of aluminum dross, (2) two-stage comminution for recovering minor rare metals from electronic appliances, and (3) concentration of platinum group metals from spent automobile catalyst. The paper also mentioned a sensor based sorting (SBS) process by combining several sensing systems, XRT and XRF, to achieve a horizontal recycling of scrap aluminum.