(151a) Rare Earth Element Recovery from e-Waste: A Techno-Economic Analysis (TEA) and Life Cycle Analysis (LCA) Case Study of Terfenol-D Scrap Recycling

The rapid growth in technological development has led to an exponential increase in the quantity of electrical and electronic equipment (EEE) being sold worldwide. The electronics market is a highly competitive industry with a strong incentive for consumption, causing a shorter life span of devices. Therefore, electronic waste (e-waste) is considered the world’s fastest-growing waste stream. Consequently, there is a strong need to develop cost-efficient technologies for recycling e-waste. In addition to solving the growing environmental risks of landfill disposal, it is a rich source of valuable metals and rare earth elements (REE). The U.S. Department of Energy (DOE) has classified REE as a crucial material for national energy security. There is increasing demand for REE as they are essential in electronics and clean energy technologies. However, China supplies nearly all the REE, which has recently worsened a global supply disruption. This supply issue has motivated countries to develop other ways to recover REE without requiring mining. Recovering REE from e-waste can lower the dependence on REE mining, stabilize global REE market prices, and reduce the environmental impacts of REE landfilling.

This paper presents a technical and environmental assessment of the steps involved in recycling terfenol-D. Terfenol-D is a magnetostrictive material with a wide range of applications ranging from ultrasonic transducers to fuel injectors. We evaluated terfenol-D recovery at a single facility processing about 10 tons per year of hard drive scraps using various solvents to isolate terbium (Tb) oxide and dysprosium (Dy) oxide. Tb and Dy are the primary components of terfenol-D. The recovery process employs various solvent combinations and high-temperature calcination. We employed Biosteam to develop a chemical process model and gather material and energy balances. Techno-economic analysis is based on a multi-year discounted cash flow rate of return analysis focused on estimating the minimum selling price of Tb and Dy oxides. Life cycle analysis was conducted in OpenLCA using the EcoInvent database and Recipe Midpoint (H) method with various allocation methods. Costs and emissions were compared to market prices and environmental impacts of similar REE.

Our preliminary results indicate that recycling 10 tons per year of terfenol-D scrap requires a total capital investment of $391,902. The estimated minimum selling price for Tb oxide is $20,000 to $70,000 per ton. This price is competitive with recent terfenol-D prices of $28,270 per ton. We estimate that the payback period for this process is 1 year. The LCA is on-going. Future work will look at the potential for regional and national-scale terfenol-D recycling programs. We thank DOE STTR for funding this project.