Recent progress in electrochemical recycling of waste NdFeB magnets

Abstract

Neodymium iron boron (NdFeB) magnets are critical components in green energy technologies and have received increasing attention due to the limited availability of the raw materials, specifically rare earth elements (REEs). The supply risks associated with primary mining of RE ores, which have significant environmental impacts, underscore the necessity for recycling RE secondary resources. Waste NdFeB magnets, generated during manufacturing processes and recovered from end-of-life products, represent valuable RE secondary resources. Recycling these materials can ensure a reliable and sustainable supply of REEs. Compared to conventional metallurgical processes, electrochemical strategies offer advantages such as high efficiency, selectivity, ease of operation, and environmental friendliness. This review presents an overview of the current status and future prospects of electrochemical technologies for recovering RE metals, alloys, or compounds from waste NdFeB magnets. Special emphasis is placed on molten salt electrolysis and room-temperature electrolysis, including detailed reaction mechanisms involved in the recycling processes. Additionally, challenges and future strategies for the electrochemical recycling of waste NdFeB magnets, focusing on environmental impact evaluation, efficient recovery, and reduced reagent consumption are proposed.