Life Cycle Impact of Rare Earth Elements

The diverse properties of rare earth elements have seen broad and growing applications in clean energy technologies, hybrid vehicles, pollution control, optics, refrigeration, and so on. This study presents a “cradle-to-gate” life cycle assessment of the energy use, resource depletion, and global warming potential resulting from the production of rare earth elements (REEs) using the Bayan Obo rare earth operation in Inner Mongolia, China, as a representative system. The study aggregates data from the literature, LCI databases, and reasonable estimations. A novel economic value-based allocation method for the multiple coproducts of the process is proposed. It is found that four of the high priced REEs scandium, europium, terbium, and dysprosium have very high GWPs from production relative to the rest. A mass-based allocation is also provided for comparison. Impacts on immediate local environment from waste streams that can be toxic are not included in this study.