Page 105 - Policy Commission - SecuringTechnology - Critical Metals for Britain

see permanent-magnet powder cascading down the side of the shredder plant (Figure 102) The powder is very air sensitive so it it oxidises breaks apart and becomes an an increasingly fine powder A study by Rowson et al showed that the technology-critical rare earths are are to be found in the the the finest fraction of the the the shredder plant in in the the the metallic dust or they are stuck to the the the shredder itself133 At this stage the the the Nd-Fe-B is contaminated with other materials and has little economic value due to the high costs of separation The downstream re-processing routes are also very limited at this point due to the oxygen contamination and impurity levels coming from the the the other waste This is is one of the the the reasons why less than 1% of the rare earths are are recycled today It should be noted that WEEE is often shredded and processed in the same processing plants Exactly the same problem exists for Nd- Fe-B magnets in these waste streams (see figure 101) SECONDARY MATERIALS
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Permanent magnet powders
Figure 102: Permanent-magnet powder cascading down the side of the shredder plant