A1 Journal article (refereed), original research (Journal article, original research)

Selective Acid Leaching of Rare Earth Elements from Roasted NdFeB Magnets


Open Access hybrid publication


Publication Details

Authors: Laatikainen Markku, Makarova Irina, Sainio Tuomo, Repo Eveliina

Publisher: Elsevier

Publication year: 2021

Language: English

Related journal or series: Separation and Purification Technology

Volume number: 278

ISSN: 1383-5866

eISSN: 1873-3794

JUFO level of this publication: 2

Digital Object Identifier (DOI): http://dx.doi.org/10.1016/j.seppur.2021.119571

Open Access: Open Access hybrid publication


Abstract

Acid leaching of Nd and Fe from roasted NdFeB magnet powders was studied in stirred-tank and packed-bed reactors. The experimental data at sulfuric acid concentrations of 0.02–1.0 mol/L and at 80 °C were correlated using a diffusion–reaction model assuming homogeneous distribution of the constituents in the magnet. The results show that the experimental data can be correlated well when formation of NdFeO3 during roasting is taken into account. Decomposition of NdFeO3 to Nd3+(aq) and Fe3+(aq) is the main route in neodymium dissolution from roasted NdFeB. The model parameters derived from stirred-tank data predict reasonable well leaching in packed-bed reactor. In both systems, re-precipitaion of iron due to acid depletion allows selective dissolution of Nd and other rare earth elements.


Last updated on 2021-09-12 at 09:13