Article

On the pre-treatment for recycling spent NdFeB permanent magnets: from disassembling, characterisation to de-coating

Camila Pucci CoutoMetals Production Refining and Recycling, Department of Materials Science and Engineering, Faculty of Mechanical Engineering, Delft University of Technology, Mekelweg 2, 2628, CD, Delft, the NetherlandsJohannes J. M. M. van de VenMetals Production Refining and Recycling, Department of Materials Science and Engineering, Faculty of Mechanical Engineering, Delft University of Technology, Mekelweg 2, 2628, CD, Delft, the NetherlandsYongxiang YangMetals Production Refining and Recycling, Department of Materials Science and Engineering, Faculty of Mechanical Engineering, Delft University of Technology, Mekelweg 2, 2628, CD, Delft, the NetherlandsShoshan T. AbrahamiMetals Production Refining and Recycling, Department of Materials Science and Engineering, Faculty of Mechanical Engineering, Delft University of Technology, Mekelweg 2, 2628, CD, Delft, the Netherlands

2024en

ABI

Abstract

An evaluation of neodymium‑iron‑boron permanent magnets (NdFeB PMs) from different end-of-life products, as a secondary resource of rare-earth elements (REEs), is presented. De-coating of PM was investigate as pre-treatment to facilitate efficient direct magnet recycling. Thus, critical aspects from disassembling to the de-coating of the magnets were addressed. A challenge for the de-coating process is that the magnets have different sizes, weights, and their coating compositions are not known beforehand. It was shown that ammonia-based solutions was thermodynamically suitable to dissolve nickel and zinc coatings selectively, while keeping the bulk magnet stable. Nevertheless, the dissolution of Zn was much faster than the Ni one, and more efficient.

Identifiers

DOI: 10.1016/j.susmat.2024.e01041

Citations and references

Cited by 20 references

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