P. Zhang, H. Liang, A. Medley, T. Levitskaia, R. Riman, C. Tsouris, Y. Katsenovich
FIPR Institute, Florida Poly,
United States
Keywords: rare earth elements (REE), phosphogypsum, leaching, cement, ammonium sulfate
Summary:
In collaboration with PNNL, Rutgers, ORNL and FIU, the FIPR Institute, Florida Poly secured a multi-year project through the Critical Materials Innovation (CMI) Hub (formerly Critical Materials Institute), funded by the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Advanced Materials and Manufacturing Technologies Office. The project is designed to integrate recovery of critical elements into total utilization of phosphogypsum (PG) through complete recovery of the REE and P values, reduction of radionuclides, purification of calcium sulfate, production of an alternative fertilizer with CO2 sequestration, generation of inexpensive cement components, and manufacturing of low-carbon footprint cement. This paper presents some of the results from the first two years of the CMI project with a focus on REE leaching and production of byproducts. Detailed analysis of different size fractions indicated possible radioactivity reduction, REE recovery and PG upgrading by physical separation methods. REE leaching recovery of >90% was achieved by two different approaches. Calcium carbonate was successfully synthesized hydrothermally using untreated, leached and purified PG forms.