Rare-Earth Elements Recovery from Electronic Waste: Techno-Economic and Life Cycle Analysis

Rare-earth elements (REE) possess unique magnetic, luminescent, and catalytic properties, making them key resources for diverse applications. They are critical components in electronic devices, industrial components, military defense equipment, and various clean energy technologies. Electronic waste (e-waste) constitutes a rich source of REE. E-waste REE recovery can lower the dependence on mining, stabilize REE market prices, and reduce the environmental impact of landfilling. Thus, researchers have been focused on developing technologies to recover REE from e-waste. This article presents a technoeconomic (TEA) and environmental (LCA) assessment of didymium oxide recovery from hard drive shreds through acid-free dissolution recycling. The goal of this study is to assess the economic feasibility and the environmental impacts of the process. Results show that a facility with an annual processing capacity of 342.42 tonnes of hard drive shreds per year collects 2.53 tonnes of didymium oxide. The estimated minimum selling price (MSP) for didymium oxide is $130/kg. Sensitivity analysis suggests that further optimization of the recycling technology could potentially reduce the MSP to approximately $73/kg. The greenhouse gas (GHG) footprint is estimated at 4.91 kg CO2/kg REE. Sensitivity analysis shows that REE and CuSO4 recovery efficiency and HDD content are the primary factors impacting the MSP. A comparison of the hydrometallurgical and electrometallurgical processes showed that acid-free dissolution is an attractive e-waste strategy.