Environmental impacts of rare earth production.

Rare earth elements (REEs) are important raw materials for green technologies. However, REE mining and production uses techniques that are often not environmentally sustainable. Life cycle assessment (LCA) is a well-recognized method for evaluating the environmental impacts of products and technologies. This article provides an overview of the environmental impacts based on published LCA results of primary REE production. Existing major REE deposits (Bayan Obo in China, Mountain Pass in the United States, Mount Weld in Australia, ion-adsorption deposits in several Chinese southern provinces) and currently possible production routes are compared. Alternative minerals, such as eudialyte, are also discussed. The article shows which environmental effects can be minimized by technology optimization and environmental safety strategies. Additionally, some of the environmental impacts discussed, may be difficult to mitigate, as they depend on the mineral type. Activities along the complex process chain of REEs production that have particularly high environmental impacts are identified.