There is currently a strong economic and technical drive for research on rare earth elements (REEs), and the problems to be addressed are numerous and extremely wide in scope. This dissertation presents novel research on four topics along the journey of REEs from their initial unprocessed state in the Earth to a finished application. First, a novel detection method for lanthanides in coal fly ash is proposed based on their strong luminescence in fluoride hosts. These studies demonstrated the ability to spectrally discriminate between these lanthanide elements and indicate that it should be possible to detect them within these complex matrices when starting at leachate concentrations well below 1 part per million. Second, a thermodynamic model has been developed for calculating solubilities and speciation in aqueous Nd–Na–F–H2O systems based on new measurements of the solubility of both NdF3 and NaNdF4 as a function of pH at room temperature. Third, a new method for fabricating bonded permanent magnets with a ceramic binder was developed. From initial powder to densified pellet, remanence of melt-spun Neodymium Iron Boride (NdFeB) decreased by ~1.8%, and coercivity decreased by ~2%, resulting in a magnet with maximum energy product of 6.6 MGOe. Fourth, the particle packing of melt-spun NdFeB powders and the ceramic binder was modeled extensively. A combined experimental and theoretical approach was used to understand the packing structure of several commercial NdFeB powders by comparison of measured packing to four different packing models. The maximum packing fraction of the magnetic phase was predicted to be 0.765.
Paul J. Antonick (2026) studied this question.