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

Xuechun Zhang; Fu Gu; Jun Xie; Chengqian Zhang; Jianzhong Fu; Peng Zhao

doi:10.1016/j.wasman.2019.03.008

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

Waste Manag. 2019 Mar 15:87:805-813. doi: 10.1016/j.wasman.2019.03.008. Epub 2019 Mar 16.

Authors

Xuechun Zhang¹, Fu Gu², Jun Xie¹, Chengqian Zhang¹, Jianzhong Fu¹, Peng Zhao³

Affiliations

¹ State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China.
² State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Department of Industrial and System Engineering, Zhejiang University, Hangzhou, China; National Institute of Innovation Management, Zhejiang University, Hangzhou, China.
³ State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou, China; Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China. Electronic address: pengzhao@zju.edu.cn.

PMID: 31109585
DOI: 10.1016/j.wasman.2019.03.008

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.

Keywords: Density; Magnetic projection; Mechanical recycling; Multiple mixture; Particle separation; Waste plastics.

MeSH terms

Plastics
Recycling
Refuse Disposal*
Solid Waste
Waste Management*

Substances

Plastics
Solid Waste