US researchers develop recycling process for turning HDD magnets into new magnet material
August 14, 2018
Plasma torch depositing recycled magnet material (Courtesy Ames Laboratory)
A research team led by the U.S. Department of Energy’s Critical Materials Institute (CMI) at Ames Laboratory, Iowa State University, USA, has developed a new recycling process which turns the rare earth magnets in discarded hard disk drives (HDDs) into new magnetic material, in what is reported to be an economical and environmentally friendly manner.
In this new process, scrapped HDD magnets are collected and any protective coatings removed. The magnets are then crushed into a powder which is deposited onto a substrate using plasma spray to synthesise coatings of 0.5-1 mm thick. The properties of the end product are said to be customisable depending on processing controls.
Ryan Ott, a member of the CMI research team operating out of Ames Laboratory, explained that the new process was developed to take advantage of the increasing quantities of discarded electronics globally, and in particular the very high quantity of discarded HDDs, a which have a relatively centralised scrap source and offer a valuable supply of rare earth magnets.
While some methods for extracting the rare earth elements from electronic waste can create unwanted byproducts with a negative environmental impact, Ott stated, “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. […] The waste reduction aspect of this process is really two-fold; we’re not only reusing end-of-life magnets, we are also reducing the amount of manufacturing waste produced in making thin and small geometry magnets out of larger bulk materials.”
While the new magnetic material produced from HDD magnets cannot retain the exceptional magnetic properties of the original material, it is thought to have the potential to meet the market need for an economical solution in applications where high-strength rare-earth magnets are not required, but lower performance magnets like ferrites are not sufficient. The method could offer an efficient solution for the production of small, strong magnets for applications such as hand-held electronics.
Ames Laboratory is a U.S. Department of Energy Office of Science national laboratory. It creates innovative materials, technologies and energy solutions with the goal of solving pressing global challenges. CMI is a Department of Energy Innovation Hub led by Ames Laboratory and supported by the Office of Energy Efficiency and Renewable Energy’s Advanced Manufacturing Office, which supports early-stage research to advance innovation in US manufacturing and promote the country’s economic growth and energy security.
