Date of Award
Doctor of Philosophy (PhD)
Rare earth elements (REEs) are strategic materials of extreme importance to both military and civil applications. REEs are mined and processed because of their criticality. End of life rare earth metals are recycled for efficient use of natural resources and also to ensure supply of these critical raw materials. By using hydro- or pyro-metallurgical approaches, REEs can be processed from mined ore or recycled from magnets and other materials as rare earth oxides, fluorides and chlorides. Typically, rare earth oxides are dissolved in a molten halide bath, converted to metal by electrolysis at elevated temperatures, and then recovered as a liquid upon tapping and, later, as a solid upon casting and cooling. This research focuses on advanced separations which differences in physical and chemical properties of the molten bath are taken advantage of to yield effective recovery of neodymium metal. To achieve the neodymium metal recovery, a unique approach using novel potential (E)-pO2- diagrams coupled with cyclic voltammetry (CV) and electrowinning (EW) was employed. Another aspect includes the use of a novel hydrometallurgical method to recycle neodymium magnets to produce neodymium fluoride so it could also become a feedstock to the molten bath considered in this work.
Sarfo, Prince, "RECOVERY OF RARE EARTH ELEMENTS BY ADVANCED PROCESSING TECHNOLOGIES" (2019). Graduate Theses & Non-Theses. 232.