Highlights Impurity Removal Metallurgical Tests Yield Allanite Rare Earths Processing Breakthrough: Impurity removal is one of the last steps in the hydrometallurgical processing of rare earths elements (“REE”) and is performed to remove non-REE minerals from the leach liquor prior to solvent extraction and separation (i.e. the final steps before producing rare earths oxide). Historically, this has been a challenging step for processing allanite-based REEs, like Halleck Creek’s ore, as the mineral typically ...