New process of recycling rare earth magnets
Researchers from the U.S. Department of Energy’s Critical Materials Institute (CMI) have created a new recycling process that turns old hard disk drive (HDD) magnets into a brand-new magnet material with just a few steps. This new process overcomes economic and environmental problems that have plagued e-waste mining for valuable materials for years.
The CMI researchers thought that it was important to focus on e-waste because one of the most abundant sources of rare earth magnets is hard disk drives that are thrown away all the time. “There are a lot of ways to go about getting the rare-earth elements out of e-waste, and some of them are very effective, but some create unwanted by-products and the recovered elements still need to be incorporated into a new application,” said Ryan Ott, Ames Laboratory scientist and member of the CMI research team. “Here we have eliminated as many processing steps as we can, and go straight from the discarded magnet to an end product, which is a new magnet.”
In this new process, the discarded HDD magnets are collected and any protective coatings are removed. The magnets are then crushed into a powder that is put into a substrate with a plasma spray. This plasma spray synthesizes the coatings to 0.5 to 1 mm thick. The new magnet material can’t retain the same magnetic properties as the original material. Despite this, the new magnet still gives the market an economical choice in an area where a high-performance earth magnet isn’t needed but lower-performance magnets like ferrites won’t work. “This waste reduction aspect of this process is really two-fold; we’re not only reusing end-oflife magnets but we are also reducing the amount of manufacturing waste produced in making thin and small geometry magnets out of larger bulk materials,” added Ott.