Short-process recycling of Nd-Fe-B sintered magnet sludge wastes: Challenges and approaches

Nd-Fe-B sintered magnet sludge wastes are one kind of typical commodity of recyclable rare-earth permanent magnet resources, and recycling such kind of wastes with economical and environmentally friendly techniques is crucial to the sustainable rare-earth industry. However, the current multi-stage wet process recycling technique for the sludge wastes involves high fabrication cost, excessive energy consumption, and heavy environmental burden. Therefore, short-process recycling techniques for Nd-Fe-B sintered magnet wastes have drawn increasing attention in the past decades. In this paper, we review recent efforts into short-process recycling Nd-Fe-B sintered magnet sludge wastes with emphasis on in-situ recycling techniques.