Permanent magnets in the material life cycle

Motor recycling project MORE aims to prevent supply shortfalls

Prof. Dr. Jörg Franke and his team from the Institute for Automated Manufacturing and Production Engineering (FAPS) at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) are involved in the MORE (Motor recycling) project – a project which devotes special attention to the recycling of permanent magnets and, in particular, to the rare earth metals they contain. Siemens is leading a consortium made up of partners from industry and figures from research institutions which will carefully examine the entire value added chain – from the design and production of motors to their reverse logistics and reuse in vehicles. This research and development project, which aims to conserve resources within the framework of “key technologies for electromobility” (STROM) is supported by the German Federal Ministry of Research.

The magnets used in the motors of electric and hybrid vehicles weigh approx. one kilogram, almost a third of which can be attributed to rare earth metals. These metals ensure that magnetised iron permanently retains its magnetic field without the additional supply of an electric current. Rare earth metals owe their rather misleading name to the story behind their discovery. They are, in fact, relatively abundant in the Earth’s crust, however, extensive mineral deposits that can be profitably exploited are less easy to find. The largest deposits can be found in Inner Mongolia.

In recent years, this has secured market dominance for China which the People’s Republic exploits to implement its extremely restrictive export policy – and export quotas which have been massively tightened on many occasions. Despite the ongoing search for other sources and the emergence of alternative solutions, the recycling of electric motors remains an important option. The demand for rare earth metals is set to increase significantly over the coming years – in part, due to the fact that demand for electric and hybrid vehicles is forecast to rise in the future. Over and above this, there are environmental issues to be considered: the already partially toxic metals are leached using acid – however, the result of this separation process is the accumulation of radioactive slurry.

The researchers involved in the MORE project are therefore pursuing various approaches to enable the recycling of electric motors, such as the removal of magnets from old motors, the repair and subsequent reuse of the motor or its components, as well as the mechanical and feedstock recycling of magnetic materials and rare earth metals by recovering pre-sorted and shredded material. In addition to this, they intend to create concepts for a recyclable motor design, analyse the relationship between economic value and the consequences of production on the environment, as well as devise models for material life cycles.

The research findings from MORE will be published in 2014. The project is being conducted by experts from Siemens, Daimler, Umicore and Vacuumschmelze, Universität Erlangen-Nürnberg, Technische Universität Clausthal, the Institute for Applied Ecology Darmstadt and the Frauenhofer Institute for System and Innovation Research. Newly developed technologies can also be of possible future benefit to other areas of research where rare earth metals play a key role, for example in wind power stations.

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uni | media service | research No. 1/2012 on 10.1.2012