In recent years, rare earth elements (REEs) such as Nd, Pr, and Dy have drawn tremendous attention due to their substantially increasing use in the form of permanent magnets in hybrid and electric vehicles, wind turbines, mobile phones, tablets, personal computers, and a wide range of devices with electric motors. To address the scarcity of these REEs, we have developed a supported membrane solvent extraction (MSX) process for the recovery of REEs from scrap permanent magnets. Further, the scalability of this MSX system was demonstrated by processing a large quantity of feedstocks from various scrap magnet sources, using larger area membrane modules. The separation results show that the REE recovery of &gt;99% with purity of &gt;99.5% was achieved from several high-volume scrap magnet feedstocks. However, the stability of the organic phase is critical for scaling up the process. We have investigated the organic phase after their long term exposure to the MSX system using gas chromatography coupled with mass spectrometer. The analysis showed potential pathways to the formation of degradation products of diglycolamide based extractant. These degradation products may be derived from the cleavages of the backbone of the extractant molecule through hydrolysis. We will discuss the details of the degradation results, pathways and mechanism, and their final effects on the performance of the MSX system. <br/>

Selective recovery of rare earth elements from e-waste with supported membrane solvent extraction

2019 Spring National Meeting

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