Rare Earth Elements (REEs) are used in a range of products and manufacturing processes – including permanent magnets, catalysts, fiber optics, and phosphor displays – critical to wind turbines, cell phones, and electric vehicles, among other modern technologies. REEs comprise 17 elements, including scandium, yttrium, and the lanthanide series. REE extraction, separation, and purification from a complex feedstock can be environmentally degrading, energy inefficient, and difficult to permit in the United States.