Rare earth element extraction from hard disk drive magnets

Hard disks typically have two neodymium (rare earth) magnets. The magnets contain about 30% rare earth elements, mainly Nd.

Magnets from 80 hard disks were investigated in the REEgain project and found to contain up to 4% of the valuable and critical heavy rare-earth element dysprosium, Dy. Dysprosium is used when neodymium magnets are used at higher temperatures such as in the motor of an hybrid or electric car (HEV's). This finding is completely new and is valuable info. In most rare-earth mines in the world, light rare earths are mined since the heavy rare earths such as dysprosium are lacking. So these magnets turn out to be a good source for dysprosium.

In order to reuse these magnets various routes can be used. Either to recycle the magnet as it is. Or crush it into powder.

Another method is to separate the rare-earth elements by chemical routes. This was done successfully during the present work.

Figure: Rare earth product from recycled hard disk drive magnets. Purity: >99%.

Contact: Andreas Peter Vestbø, aspv@teknologisk.dk, +45 7220 2827