The recovery of neodymium from post-consumer products is gaining significant interest. To study the recycling feasibility of neodymium in end-of-life (EOL) computer hard disc drives (HDDs), NdFeB magnets were collected using a steel grate during commercial shredding, followed by thermal demagnetisation, grinding and screening to yield an upgraded scrap. Two metallurgical extraction routes were investigated. The first is a high temperature molten slag extraction followed by H2SO4 leaching at room temperature. Both CaO-SiO2-Al2O3 and CaO-CaF2 slag systems were tested with more than 99% rare earths recovery, but with incomplete leaching. In the second route, the upgraded scrap was directly leached to dissolve 97% rare earth content. In both cases, 98% of the rare earths in the leach solution were subsequently converted into a high purity (98.4%) rare earths double salt (NaNd(SO4)2·H2O) that can be converted to either RF3 or R2O3, the two common raw materials in the production of rare earth metals.

Original languageEnglish
Pages (from-to)106-115
Number of pages10
JournalTransactions of the Institutions of Mining and Metallurgy: Section C
Issue number2
Publication statusPublished - 1 Jun 2015

    Research areas

  • Hydrometallurgy, NdFeB magnets, Physical separation, Pyrometallurgy, Rare earth elements, Recycling

ID: 34917759