(381i) Separation of NdFeB Scrap Powder from Hard Disk Drive By HD Process

Rare earth magnets based on NdFeB have been used in many clean energy and advanced applications, including Hard Disk Drive (HDD), electric vehicles, and electric generators in wind turbines. However, the rare earth elements such as neodymium and dysprosium are at highest supply risk of all metals for clean technologies. Therefore, the recycling of NdFeB magnets based on these materials can provide additional and securing supply. Hard Disk Drive (HDD) have been identified as one of the most abundant and readily available forms of Waste Electronics and Electrical Equipment (WEEE) scrap. However the separation of magnet is difficult because the magnet is glued into its functional position, fully magnetized, and coated with e.g. Ni for corrosion protection. It is well known that NdFeB material is hydrogenated by hydrogen gas during the Hydrogen Decrepitation (HD) process and subsequently crushed and pulverized due to a stress generated by volume expansion of the hydrogenated phases. Lately, a few studies have reported the possibility of HD process being an alternative method to effectively separate NdFeB magnets from waste HDD as anti-oxidant powders. However, the mechanistic and systematic study is still required to evaluate the several process factors and establish the optimal condition for selective and efficient extraction of NdFeB magnets from waste HDD. In this study, the effects of temperature, hydrogen pressure and magnet size on the pulverization of waste NdFeB magnets in HD process were investigated, and the separation process of magnets from HDD was established. More details will be discussed in the presentation.