P. Zhang, H. Liang, A. Medley, T. Levitskaia, R. Riman, C. Tsouris, Y. Katsenovich
FIPR Institute, Florida Poly,
United States
Keywords: phosphogypsum, rare earths, solvent extraction, cement. hydrothermal synthesis
Summary:
In collaboration with PNNL, ORNL, Rutgers, and FIU, the FIPR Institute is leading a multiyear project aimed at achieving total utilization of Florida phosphogypsum (PG). The project focuses on fully recovering rare earth elements (REEs) and phosphorus (P), reducing radionuclide content, purifying calcium sulfate, converting purified PG into a fertilizer with CO₂ sequestration potential and high-purity calcium carbonate, and developing low-energy cement using the PG-converted calcium carbonate. This research is supported by the Critical Materials Innovation Hub, funded by the U.S. Department of Energy’s Office of Energy Efficiency and Renew able Energy, Advanced Materials and Manufacturing Technologies Office. Preliminary results include: 1) ~90% REE leaching recovery from PG, 2) Design of a membrane system for REE extraction, 3) Development of a physical separation process capable of lowering radioactivity in a substantial fraction (>80% by weight) of PG, enabling extraction of critical elements, recovery of phosphate value, and large-scale commercial applications of PG, 4) 95% REE extraction from PG leachate, with stepwise stripping to separate LREEs from HREEs, and 5) Low-temperature (<500 °C) cement production via hydrothermal synthesis.