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Advanced Technology Development for Production of Individually Separated, High Purity, (ISHP) Rare Earth Oxides/Rare Earth Salts (REO/RES)


a.      Advanced Technology Development for Production of Individually Separated, High Purity, (ISHP) Rare Earth Oxides/Rare Earth Salts (REO/RES)

Commercial sources of rare earth elements include bastnaesite (La, Ce)FCO3, monazite, (Ce, La, Y, Th)PO4, and xenotime, YPO4. Processing of these materials to extract and recover REE typically begins with physical beneficiation (mineral processing as crushing, grinding, density separation, magnetic separation, etc.), and is typically followed by chemical separation (i.e., hydrometallurgy: the technique or process of extracting metals at ordinary temperatures by leaching ores with liquid solvents), leading to the production of a mixed rare earth concentrate. Separation of the individual rare earths from each other was considered to be difficult, due to similar physical and chemical properties of the elements. Ion-exchange and solvent extraction techniques were developed in order to produce high purity single rare earth solutions or compounds. Alternate methods to concentrate, recover and separate rare earths include precipitation and coprecipitation, electrochemical and membrane processes, adsorption as well as oxidation and reduction processes.


Solvent extraction is generally accepted as the primary commercial technology for separating rare earths. Rare earth solvent extraction processes are generally classified as primary separations, which focus on separating rare earth elements from other elements, and secondary separations, which produce single or mixed (typically 2 or 3) rare earth products from mixed rare earth streams that are produced by primary separations. Commercially, D2EHPA, HEHEHP, Versatic 10, TBP, and Aliquat 336 have been widely used in rare earth solvent extraction processes. Up to hundreds of stages of mixers and settlers may need to be assembled in order to achieve the necessary extent of separation and product purity [1,2].


Applicants shall focus their proposals on:

·         Providing a summary review of (1) the literature with respect to the state-of-the-art techniques and (2) utilization of these techniques for the separation of mixed rare earth oxides (MREO) and rare earth salts (MRES) into individually separated, high purity (ISHP) materials. These techniques shall include, but not be limited to solvent extraction, ion chromatography, electrowinning, sublimation/condensation, etc.

·         Concept development for advanced processes/methodologies that address production of individually separated, high purity (i.e., ~90-99.99%) (ISHP), rare earth oxides (REO) and/or rare earth salts (RES) at a cost that is ~20% lower than the cost of producing these materials using currently available conventional separations technologies as solvent extraction, or alternate proven or commercially utilized separation techniques. Provide a detailed description of proposed advanced ISHP, reduced cost, separation processes.

·         Laboratory-scale proof-of-concept testing demonstrating

o   Separation of mixed light rare earth oxides/rare earth salts (MLREO/MLRES) from heavy rare earth oxides/rare earth salts (HREO/HRES)

o   Separation of the MLREO/MLRES into ISHP LREO/LRES

o   Separation of the MHREO/MHRES into ISHP HREO/HRES at a cost that is ~20% lower than that of conventional, commercially used, technologies.

·         Conduct of a preliminary techno-economic assessment (TEA) to address/validate the ~20% reduction of processing costs for each advanced separation concept.

·         Preliminary systems design for process scale-up for production 100-1000gm of ISHP REO/RES materials.

·         Final Report addressing each of the bulleted items identified above.


Questions – Contact: Mark Render,


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