The Effect of Grinding and Roasting Conditions on the Selective Leaching of Nd and Dy from NdFeB Magnet Scraps

Metals

Ho-Sung Yoon²  Chul-Joo Kim²  Kyung Woo Chung²  Sanghee Jeon¹  Ilhwan Park¹  Kyoungkeun Yoo¹  Manis Kumar Jha³ 

[1] Department of Energy & Resources Engineering, Korea Maritime and Ocean University (KMOU), Busan 606-791, Korea; E-Mails:;Minerals Resource Research Division, Korea Institute of Geoscienece & Mineral Resources (KIGAM), Daejeon 305-350, Korea; E-Mails:;Metal Extraction & Forming Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831007, India; E-Mail:

关键词: NdFeB magnet scraps;    selective leaching;    acetic acid leaching;    roasting;    planetary ball milling;   

DOI  :  10.3390/met5031306

来源: mdpi

【 摘 要 】

The pretreatment processes consisting of grinding followed by roasting were investigated to improve the selective leaching of Nd and Dy from neodymium-iron-boron (NdFeB) magnet scraps. The peaks of Nd(OH)₃ and Fe were observed in XRD results after grinding with NaOH as the amount of water addition increased to 5 cm³. These results indicate that the components of Nd and Fe in NdFeB magnet could be changed successfully into Nd(OH)₃ and Fe, respectively. In the roasting tests using the ground product, with increasing roasting temperature to 500 °C, the peaks of Nd(OH)₃ and Fe disappeared while those of Nd₂O₃ and Fe₂O₃ were shown. The peaks of NdFeO₃ in the sample roasted at 600 °C were observed in the XRD pattern. Consequently, 94.2%, 93.1%, 1.0% of Nd, Dy, Fe were leached at 400 rpm and 90 °C in 1 kmol·m⁻³ acetic acid solution with 1% pulp density using a sample prepared under the following conditions: 15 in stoichiometric molar ratio of NaOH:Nd, 550 rpm in rotational grinding speed, 5 cm³ in water addition, 30 min in grinding time, 400 °C and 2 h in roasting temperature and time. The results indicate that the selective leaching of Nd and Dy from NdFeB magnet could be achieved successfully by grinding and then roasting treatments.

【 授权许可】

CC BY   
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