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 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 degrees 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.

Automated summary

This paper proposes a pyrometallurgical recycling method for end-of-life NdFeB magnets, achieving the recovery of rare earth elements (REEs) and producing a new concentrate. The metal phase obtained from the smelting process has a high Fe content, while the slag phase contains a mixture of RE-oxides and Fe2O3. The obtained slag concentrate can be further treated to obtain rare earth elements.