Environmental impacts of a circular recovery process for hard disk drive rare earth magnets

Hard disk drives (HDDs) are prioritized by many stakeholders for implementation of circular economy initiatives due to their value and critical material content. Rare earth (RE) magnets are of particular interest for recovery and reuse (R&R), but the business model has not been demonstrated for feasibility at a large scale. This study assessed a pilot-scale R&R process for RE magnet assemblies and compared the environmental impacts with business as usual (BAU) (i.e. shredding whole HDDs at end-of-life), using life cycle assessment (LCA). The process was implemented by two major stakeholders in the HDD value chain - a large HDD user (i.e., data center) and a HDD manufacturer. Primary data on materials, transportation, and electricity inputs were collected from dismantling 6100 end-of-life HDDs in a data center, transporting the retrieved RE magnet assemblies to a HDD manufacturer, and placing them in new HDDs for reuse. LCA results indicated an 86% reduction in global warming potential: 3.70 kg CO2-eq per set of magnet assemblies from one HDD compared to the BAU system. The environmental benefit was predominantly due to foregoing the RE magnet production, which is the most energy and chemically intensive process within the magnet assembly. This pilot also highlighted the benefits of a collocated R&R process with data centers to address (1) data security concerns, (2) transboundary shipments of e-waste (whole HDDs vs. components), and (3) the need for a qualified manufacturing process for disassembly, which is required to reuse components in new HDDs.