Recovery of Rare Earth Elements from Spent NdFeB-Magnets: Separation of Iron through Reductive Smelting of the Oxidized Material (Second Part)

Hanwen Chung; Srecko Stopic; Elif Emil-Kaya; Sebahattin Gürmen; Bernd Friedrich

doi:10.3390/met12101615

Recovery of Rare Earth Elements from Spent NdFeB-Magnets: Separation of Iron through Reductive Smelting of the Oxidized Material (Second Part)

Hanwen Chung
, Srecko Stopic^*
, Elif Emil-Kaya
, Sebahattin Gürmen
, Bernd Friedrich

^*Corresponding author for this work

Department of Metallurgical and Materials Engineering

Research output: Contribution to journal › Article › peer-review

21 Citations (Scopus)

Abstract

This paper proposes a pyrometallurgical recycling method for end-of-life NdFeB magnets by oxidizing them in air and subsequently smelting them. The smelting process enabled the recovery of rare earth elements (REEs), producing a new reach concentrate separating the iron as a metallic phase. From the products of smelting, the metallic phase showed a maximum Fe content of 92.3 wt.%, while the slag phase showed a maximum total REE (Nd, Pr, and Dy) content of 47.47 wt.%, both at a smelting temperature of 1500 °C. ICE-OES and XRD analysis were conducted on both phases, and results showed that the metal phase consists mainly of Fe and Fe₃C while the slag phase consists of the RE-oxides, leftover Fe₂O_3, and a mixture of Fe₆Nd_4. The obtained slag concentrate based on the oxides of rare earth elements is suitable for further pyrometallurgical or hydrometallurgical treatment in order to obtain rare earth elements.

Original language	English
Article number	1615
Journal	Metals
Volume	12
Issue number	10
DOIs	https://doi.org/10.3390/met12101615
Publication status	Published - Oct 2022

Bibliographical note

Publisher Copyright:
© 2022 by the authors.

Funding

This research was funded by the Federal Ministry for Economic Affairs and Climate Action, grant number 273 EN, and The Scientific of Technological Research Council of Turkey under grant agreement 120N33. The APC was funded by the project “Sustainable recovery of rare earth elements (Nd, Pr, Dy) from spent magnets”.

Funders	Funder number
Federal Ministry for Economic Affairs and Climate Action	273 EN
Türkiye Bilimsel ve Teknolojik Araştırma Kurumu	120N33

Keywords

magnets
oxidation
rare earth elements
recycling
smelting

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10.3390/met12101615

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title = "Recovery of Rare Earth Elements from Spent NdFeB-Magnets: Separation of Iron through Reductive Smelting of the Oxidized Material (Second Part)",

abstract = "This paper proposes a pyrometallurgical recycling method for end-of-life NdFeB magnets by oxidizing them in air and subsequently smelting them. The smelting process enabled the recovery of rare earth elements (REEs), producing a new reach concentrate separating the iron as a metallic phase. From the products of smelting, the metallic phase showed a maximum Fe content of 92.3 wt.\%, while the slag phase showed a maximum total REE (Nd, Pr, and Dy) content of 47.47 wt.\%, both at a smelting temperature of 1500 °C. ICE-OES and XRD analysis were conducted on both phases, and results showed that the metal phase consists mainly of Fe and Fe3C while the slag phase consists of the RE-oxides, leftover Fe2O3, and a mixture of Fe6Nd4. The obtained slag concentrate based on the oxides of rare earth elements is suitable for further pyrometallurgical or hydrometallurgical treatment in order to obtain rare earth elements.",

keywords = "magnets, oxidation, rare earth elements, recycling, smelting",

author = "Hanwen Chung and Srecko Stopic and Elif Emil-Kaya and Sebahattin G{\"u}rmen and Bernd Friedrich",

note = "Publisher Copyright: {\textcopyright} 2022 by the authors.",

year = "2022",

month = oct,

doi = "10.3390/met12101615",

language = "English",

volume = "12",

journal = "Metals",

issn = "2075-4701",

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T1 - Recovery of Rare Earth Elements from Spent NdFeB-Magnets

T2 - Separation of Iron through Reductive Smelting of the Oxidized Material (Second Part)

AU - Chung, Hanwen

AU - Stopic, Srecko

AU - Emil-Kaya, Elif

AU - Gürmen, Sebahattin

AU - Friedrich, Bernd

PY - 2022/10

Y1 - 2022/10

N2 - This paper proposes a pyrometallurgical recycling method for end-of-life NdFeB magnets by oxidizing them in air and subsequently smelting them. The smelting process enabled the recovery of rare earth elements (REEs), producing a new reach concentrate separating the iron as a metallic phase. From the products of smelting, the metallic phase showed a maximum Fe content of 92.3 wt.%, while the slag phase showed a maximum total REE (Nd, Pr, and Dy) content of 47.47 wt.%, both at a smelting temperature of 1500 °C. ICE-OES and XRD analysis were conducted on both phases, and results showed that the metal phase consists mainly of Fe and Fe3C while the slag phase consists of the RE-oxides, leftover Fe2O3, and a mixture of Fe6Nd4. The obtained slag concentrate based on the oxides of rare earth elements is suitable for further pyrometallurgical or hydrometallurgical treatment in order to obtain rare earth elements.

AB - This paper proposes a pyrometallurgical recycling method for end-of-life NdFeB magnets by oxidizing them in air and subsequently smelting them. The smelting process enabled the recovery of rare earth elements (REEs), producing a new reach concentrate separating the iron as a metallic phase. From the products of smelting, the metallic phase showed a maximum Fe content of 92.3 wt.%, while the slag phase showed a maximum total REE (Nd, Pr, and Dy) content of 47.47 wt.%, both at a smelting temperature of 1500 °C. ICE-OES and XRD analysis were conducted on both phases, and results showed that the metal phase consists mainly of Fe and Fe3C while the slag phase consists of the RE-oxides, leftover Fe2O3, and a mixture of Fe6Nd4. The obtained slag concentrate based on the oxides of rare earth elements is suitable for further pyrometallurgical or hydrometallurgical treatment in order to obtain rare earth elements.

KW - magnets

KW - oxidation

KW - rare earth elements

KW - recycling

KW - smelting

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U2 - 10.3390/met12101615

DO - 10.3390/met12101615

M3 - Article

AN - SCOPUS:85140932398

SN - 2075-4701

VL - 12

JO - Metals

JF - Metals

IS - 10

M1 - 1615

ER -

Recovery of Rare Earth Elements from Spent NdFeB-Magnets: Separation of Iron through Reductive Smelting of the Oxidized Material (Second Part)

Abstract

Bibliographical note

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Keywords

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