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

Frost, Kali; Sousa, Inês Pereira de; Larson, Joanne; Jin, Hongyue; Hua, Inez

doi:10.1016/j.resconrec.2021.105694

Cited by 9 publications

(6 citation statements)

References 25 publications

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“…The target product or “functional unit” for this study is a set of REE magnet assemblies (VCMA from a 16TB enterprise HDD, described by Frost et al [ 2021 ]). The REE magnet assembly examined in this study was considered a reasonable proxy for other HDD magnet assemblies currently in production.…”

Section: Methodsmentioning

confidence: 99%

“…To construct the detailed unit process (UP) data required for a spatially explicit assessment, UP inventory data from Bailey et al ( 2020 ) were used to build the life cycle inventory for the mining, beneficiation, acid roasting, leaching, and solvent extraction processes. Inventory data from Arshi et al ( 2018 ) were used for the conversion of REE oxides into REE metal processing steps, and finally, data from Jin et al ( 2020 ) and Frost et al ( 2021 ) were used to construct processes for neodymium, iron, and boron (NdFeB) magnet production and VCMA manufacturing (i.e., final product assembly where the magnet is epoxied into the steel bracket). In total, 95 unit production processes were used to create the UP inventory (Step 1 of Figure 2 ).…”

Section: Methodsmentioning

confidence: 99%

“…Manufacturing materials. Manufacturing locations along the REE magnet life cycle were taken from the literature (Bailey et al, 2020;Frost et al, 2021). Manufacturing occurs in more than one location for some of the UPs, and emissions were allocated based on approximate production volumes for each site where locations were known.…”

Section: Quantification Of Emissionsmentioning

confidence: 99%

“…Steel manufacturing emissions. One of the major contributors to ecotoxicity impacts is from the engineered steel bracket ("iron yoke"), which houses the REE magnet (Frost et al, 2021). This is the largest component in the assembly, with a mass of 72.6 g (combined mass of upper and lower yokes), compared to 31.2 g for the REE magnets.…”

Section: Quantification Of Emissionsmentioning

confidence: 99%

“… Process flow diagram for HDD REE magnets with locations assumed for this study (adapted from Bailey et al, 2020 ; Frost et al, 2021 ). HDD, hard disk drive; REE, rare‐earth element …”

Section: Introductionmentioning

confidence: 99%

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Regionalized chemical footprint method to identify aquatic ecotoxicity hotspots of hard disk drive rare‐earth magnets

Hua

2022

Integr Envir Assess & Manag

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The chemical footprint (ChF), which combines life cycle assessment (LCA) and quantitative risk assessment principles, shows promise for exploring localized toxicity impacts of manufacturing processes, which is not achievable with LCA alone. An updated ChF method was applied to the global annual production of a hard disk drive (HDD) rare-earth element (REE) magnet assembly, assuming a supply chain in East and Southeast Asia. Existing REE magnet assembly LCA inventories were combined with supplier manufacturing locations to create a cradle-to-gate spatial unit process inventory. Emissions from the electricity grid for each manufacturing site were downscaled to hydrobasins of interest using the Global Power Plant Database. The predicted no effect concentration (PNEC) was chosen as the ecotoxicity pollution boundary to determine the threshold for dilution of each chemical of concern (CoC) and to calculate the ChF. Finally, a high-resolution hydrological database provided volumes of the freshwater river reach draining each hydrobasin and was used to calculate the dilution capacity (DC), that is, the volume required to remain at or below the PNEC for each CoC. The total ChF of annual REE magnet assembly production was 6.91E12 m 3 , with hotspots in watersheds in China and Thailand where REEs are processed and steel metalworking takes place. Metals were the primary CoCs, with cadmium and chromium(VI) comprising 77% of total ChF. Dilution factors ranged from 5E−09 to 9E + 03 of the DC of the waterbody, reflecting the spatial variability in both emissions and DC. An advanced ChF method was demonstrated for HDD REE magnets. Scoping is a key step required to reduce model complexity. The use of regionalized fate factors and standardized hydrological data sets improves the comparability of ChFs across hydrobasins. Additional work to combine data sets into readily available tools is needed to increase usability and standardization of the ChF method and promote wider adoption.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Quantification Of Emissionsmentioning

confidence: 99%

Section: Quantification Of Emissionsmentioning

confidence: 99%

“… Process flow diagram for HDD REE magnets with locations assumed for this study (adapted from Bailey et al, 2020 ; Frost et al, 2021 ). HDD, hard disk drive; REE, rare‐earth element …”

Section: Introductionmentioning

confidence: 99%

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