In the present study the amount of permanent magnets (PM) present in waste of electrical and electronic equipment (WEEE) has been quantified. The PM was subsequently characterised by – among other techniques – scanning electron microscopy (SEM) using the TESCAN FEG-SEM MIRA3. The SEM results show that the magnets containing rare earth elements (REE) present in WEEE consist of Nd- Fe-B alloy in a tetrahedral form with an inter-granular space rich in REEs (Nd, Dy and Pr). About 20 μm thick coating layer consisting of Ni, Zn or an alloy of Cu/Ni is detected at the surface of the magnets. Properties of the PM at high temperatures are further investigated.
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- SE image of a HDD magnet sample and EDS spectra at the pointed locations.