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

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...

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Bibliographic Details
Main Authors: Hanwen Chung, Srecko Stopic, Elif Emil-Kaya, Sebahattin Gürmen, Bernd Friedrich
Format: Article
Language:English
Published: MDPI AG 2022-09-01
Series:Metals
Subjects:
Online Access:https://www.mdpi.com/2075-4701/12/10/1615
Description
Summary: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 Fe<sub>3</sub>C while the slag phase consists of the RE-oxides, leftover Fe<sub>2</sub>O<sub>3,</sub> and a mixture of Fe<sub>6</sub>Nd<sub>4.</sub> 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.
ISSN:2075-4701