Forecasting the recycling potential based on waste analysis: A case study for recycling Nd-Fe-B magnets from hard disk drives

Abstract

Recycling of rare earth metals from permanent magnets used in hard disk drives (HDDs) is an intensively investigated scenario. However, the material composition of the waste stream of data storage devices will drastically change over the coming decades because of ongoing replacement of the HDD market by solid state drives (SSD) that do not contain permanent magnets. Limited information is available on the current material composition of data storage devices and even less on how the volume and material composition of these waste streams will evolve. Nonetheless, these data are crucial to evaluate the economic viability and the potential environmental benefits of the envisaged recycling strategies and for the development of well-adjusted recycling technologies that can cope with these evolutions. Therefore, this paper presents an innovative methodology to forecast the recycling potential from both an economic and environmental perspective, while basing the forecasts on waste sampling analysis and taking into consideration the related uncertainties. In the presented case study, this methodology is applied to quantify the potential value recovery and avoided environmental impact in Belgium of recycling Hard Disk Drives (HDDs) and the Neodymium herein contained. For this analysis, a holistic approach is adopted which considers the wide variety of products in which HDDs can be found and the complete recycling chain, including collection, pre- and end-treatment. The results of the presented forecasts indicate that the number of discarded HDDs stagnates after 2013 to approximately 0.145 units per capita per year. In addition, performed analysis demonstrates that automated demanufacturing systems to separate and recycle the neodymium-iron-boron (Nd-Fe-B) voice coil magnet (VCM) are merely profitable today, whereas a sensitivity analysis indicates that the profitability strongly depends on the labor cost, annual capacity and material value.