Enabling the recycling of rare earth elements through product design and trend analyses of hard disk drives

Hard disk drives consist of a complex mix of various materials. While Aluminum, Copper and Steel are easy to separate, actual recycling processes dilute containing rare earth elements to non-recoverable grades in other material streams. To enable future recycling of these materials an in-depth analysis of hard disk drives from Desktop PCs and Notebooks was carried out. Furthermore, possible recycling strategies for rare earth elements were derived and the recycling potential was assessed. The results show high concentrations of Neodymium (22.9 ± 2.8 %), Praseodymium (2.7 ± 2.2 %) and Dysprosium (1.4 ± 1.5 %) in the magnets. Various types of alloys are applied for different technical or economic reasons. Also a dependency from manufacturing dates was evidenced. Furthermore, Cerium (0.5 %) and Neodymium (0.2 %) were determined in printed circuit boards. Test disassemblies of hard disk drives showed a complicated structure and thereby a difficult access to the NdFeB magnets. This applies explicitly for the spindle motor magnets, which hold the main share of applied Dysprosium. A WEEE collection analysis shows an amount of about 12.7t magnets from hard disk drives from PCs in Germany in 1 year. Put-on-market data predict decreasing shares of hard disk drives from Desktop PCs and significantly increasing amounts of Notebook components in WEEE.