Recycling of waste NdFeB magnets for recovery of rare earth elements by combining Pyro- and Hydrometallurgy

Autori

• Elif Emil Kaya

Parametri

• Tecnologia e Ingegneria

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Rare earth elements (REEs) and permanent magnets are essential for modern technology, yet their increasing demand has led to supply risks, prompting their classification as critical metals. The European Union Commission identified REEs as having the highest supply risk among these elements in reports from 2011 and 2020. This critical importance has spurred efforts to ensure sustainable raw material sourcing, particularly through the recycling of NdFeB magnets that have reached the end of their service life or are scrapped due to errors. While various studies have explored hydrometallurgical and pyrometallurgical methods, challenges remain, including the need for multi-stage processes to achieve high purity, excessive chemical use in conventional precipitation and oxidation, and significant REE losses during extraction. Current methods for producing RE oxides, such as oxalate and double salt precipitation, face economic and purity issues, as iron often precipitates alongside REEs, and the agents used introduce impurities. This dissertation proposes three innovative flowsheets aimed at addressing these processing challenges to enhance the recovery and purity of REEs from recycled sources.

Lingua: Inglese

Pubblicato: 2023