Magnetic density separation project grant

University of Twente’s research chair EMS receives 1 million euro funding for the application of superconducting magnets in recycling high-value materials.

The research chair Energy, Materials and Systems (EMS) at the University of Twente (UT) receives 1 million euro funding for a 5-year research project within the “Perspectief”- program of the Dutch technology foundation STW. In a national consortium with the universities of Delft, Eindhoven, Utrecht and Nijmegen as well as a series of companies, a new type of magnetic density separation (MDS) will be developed further into a widely-applicable recycling process to be employed on an industrial scale.

MDS uses a liquid such as water with magnetic nano-particles suspended in it. The materials that need to be separated (e.g. a mixture of plastics or shredded electronics) are injected into the liquid, which carries them through a magnetic field that is strong at the bottom of the fluid bed and weak at the top. Because of this field gradient, the materials not only experience the usual Archimedes-type of buoyance, but also an additional upward force caused by the displacement of the magnetic fluid away from the magnet. At a height determined by the mass density of the added material, these upward forces exactly balance gravity and the material particles neither sink nor rise any further. Physically separating the thus stratified stream into separate channels, various density fractions are straightforwardly sieved out for further processing.

In multi-disciplinary cooperation with the universities and companies mentioned above EMS will contribute towards important savings of energy and material resources, by recycling high-value materials instead of producing them from ore or oil.

The task of EMS within this program concerns the development of superconducting magnets that enable considerably higher field gradients and deeper flow channels than those achievable with permanent magnets or conventional electromagnets. These conventional techniques can realize field gradients of the order of 5 T/m and fluid beds of 10 cm height, whereas the present project aims to achieve at least 50 T/m and 30 cm. These improvements directly increase the separation resolution as well as the method’s throughput.

The consortium will appoint six PhD students in total, two of which at UT/EMS. The first EMS student starts in the beginning of 2016 with the development of a demonstrator system, that will be placed at the Delft University of Technology. A second student starts one year later and will aim at the realization of a more user-friendly industrial prototype, that will be installed at the company Umincorp.


Dr. M.M.J. Dhallé H.J.M. ter Brake