RECYCLING OF NEODYMIUM FROM PERMANENT MAGNETS

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-28-7 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 43, 189-196 pp; DOI: 10.5593/sgem2017H/43/S18.024

ABSTRACT

Due to the increased demand and supply shortage, neodymium is listed as critical raw material of the strategic importance in many countries in the world. From this point of view the researches for the development of recycling technologies for this metal are strongly justified. The paper presents the results of laboratory research on the hydrometallurgical recycling of neodymium from hard disk drivers (HDDs). Neodymium magnets are the elements of a positioner which drives the head of the HDD. The study material- sintered magnets- was obtained from the dismantling of HDDs from personal computers. In the hydrometallurgical method, the removed magnets were demagnetized by heating above the Curie point. Then, magnets were crushed and ground for an XRD analysis, which showed the Nd2F14B as the dominant phase in the sample. An XRF analysis was also carried out, which showed 22% of neodymium in the sample. The material was then leached in solutions with different concentrations of sulfuric acid. The neodymium fluoride, which was the final product, was precipitated with ammonium fluoride.

Keywords: neodymium, permanent magnets, recycling of neodymium