Magnetic projection: A novel separation method and its first application on separating mixed plastics

Abstract

A novel magnetic separation method, denoted as “magnetic projection”, was proposed. The method is based on a simple configuration: a container full of paramagnetic medium is placed beside a permanent magnet. Particles of different densities that submerge in the medium are driven by the magnetic force, moving in accordance with different trajectories, and are finally landed in different collection regions. We applied this method to separate mixed plastics, because most of the extant plastic separation processes can only deal with binary mixture. In the experiment, four common plastics such as polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate (PC), and polymethyl methacrylate (PMMA) were used to simulate the plastic mixture. The experimental results showed that the proposed method can effectively separate the plastic mixture, as the purity of each type of recovered plastics was over 95 wt%. This approach demonstrates its tremendous potential in solid waste management and worth further investigation.