Abstract
The recovery of rare earth elements from discarded electronic waste is gaining considerable interest due to the shortage of primary resources. NdFeB permanent magnets were collected from discarded hard disc drives and consist of ~ 28% rare earth values along with 65% Fe in the form of the Nd2Fe14B phase. The magnets were demagnetized, crushed and exposed to microwave irradiation for a predetermined time. It was found that, within 1.2 min of microwave exposure, significant oxidation and a temperature of ~ 600°C was attained. Recovery from the microwave-exposed product was carried out by the leaching and precipitation route. Iron values were recovered in the form of metallic iron and iron oxide in the leach residue. The process adopted is very short and yielded 56% recovery of Nd and Dy oxides with a purity of more than 98%.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
J.W. Darcy, H.M.D. Bandara, B. Mishra, B. Blanplain, D. Apelian, and M.H. Emmert, JOM 65, 1381 (2013).
I.C. Nlebedim and A.H. King, JOM 70, 115 (2018).
A.T. Abrahami, Y. Xiao, and Y. Yang, Miner. Proces. Extr. Met. 124, 106 (2015).
M.A.R. Onal, C.R. Borra, M. Guo, B. Blampain, and T.V. Gerven, J. Rare Earths 35, 574 (2017).
Y. Yang, A. Walton, R. Sheridan, K. Guth, R. Gaub, O. Gutfleisch, and K. Binnemans, J. Sustain. Metall. 3, 122 (2017).
M. Sagawa, S. Fujimura, H. Yamamoto, Y. Matsuura, and K. Hiraga, IEEE Trans. Mag. 20, 1584 (1984).
M. Firdaus, M.A. Rhamdhani, Y. Durandet, W.J. Rankin, and K. McGregor, J. Sustain. Metall. 2, 276 (2016).
F. Habashi, Can. Metall. Q. 52, 224 (2013).
C.K. Gupta and N. Krishnamurthy, Extractive Metallurgy of Rare Earths (Boca Raton: CRC Press, 2005).
IBM, Indian Minerals Yearbook 2017 (Part- III: Mineral Reviews) 56th edition: Rare Earths.
T.H. Okabe, O. Takeda, K. Fukuda, and Y. Umetsu, Mater. Trans., 44:4, 798 (2003).
C.H. Lee, Y.J. Chen, C.H. Liao, S.R. Popuri, S.L. Tsai, and C.E. Hung, Metall. Mater. Trans. A 44, 5825 (2013).
V. Hoogerstraete, B. Blanpain, T.V. Gerven, and K. Binnemans, RSC Adv. 4, 64099 (2014).
S.S. Behera and P.K. Parhi, Sep. Purif. Technol. 160, 59 (2016).
A. Kumari, M.K. Sinha, S. Pramanik, and S.K. Sahu, Waste Manag 75, 486 (2018).
D. Dupont and K. Binnemans, Green Chem. 17, 2150 (2015).
T. Horikawa, K. Miura, M. Itoh, and K.I. Machida, J. Alloy. Compd. 408, 1386 (2006).
Y. Bian, S. Guo, L. Jiang, K. Tang, and W. Ding, J. Sustain. Met. 1, 151 (2015).
M.A.R. Onal, C.R. Borra, M. Guo, B. Blampain, and T.V. Gerven, J. Sustain. Met. 1, 199 (2015).
M.A.R. Onal, E. Aktan, C.R. Borra, B. Blanpain, T.V. Gerven, and M. Guo, Hydrometallurgy 167, 115 (2017).
Y. Bian, S. Guo, L. Jiang, J. Liu, K. Tang, and W. Ding, ACS Sustainable Chem. Eng. 4, 810 (2016).
M. Nakamoto, K. Kubo, Y. Katayama, T. Tanaka, and T. Yamamoto, Metall. Mater. Trans. B 43, 468 (2012).
Y. Li, H.E. Evans, I.R. Harris, and I.P. Jones, Oxid. Met. 59, 167 (2003).
M. Zakotnik, I.R. Harris, and A.J. Williams, J. Alloys Compd. 450, 525 (2008).
S. Agrawal, V. Rayapudi, and N. Dhawan, Miner. Eng. 132, 202 (2019).
P.M. Eduafo and B. Mishra, J. Sustain. Metall. 4, 437 (2018).
R. Chi and Z. Xu, Metall. Mater. Trans. B 30, 189 (1999).
Acknowledgement
The authors would like to acknowledge the funding received from the Indian Institute of Technology, Roorkee (Faculty Initiation Grant; FIG-100714).
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Tanvar, H., Kumar, S. & Dhawan, N. Microwave Exposure of Discarded Hard Disc Drive Magnets for Recovery of Rare Earth Values. JOM 71, 2345–2352 (2019). https://doi.org/10.1007/s11837-019-03523-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11837-019-03523-7