| Abstract Scope |
Phosphogypsum (PG) is a byproduct of the fertilizer industry. Globally, over 300 mt/year of PG are produced, yet only 15% is currently recycled. The PG recycling is complicated by the presence of impurities (e.g., P2O5, F… etc.). In this study, a straightforward granulometric separation process was developed for PG purification. Impurity-bearing phases were identified and physically isolated. Results revealed that over 98 wt.% of F is enriched in coarse PG fraction, primarily hosted in co-crystallized malladrite (Na2SiF6) and fluorite (CaF2) phases. Apatite (Ca5(PO4)3(F)), enriched in the coarse fraction, was identified as the dominant P-REE-bearing phase. Removal of this PG fraction improved material purity from 96 to 98%, enabling its efficient use in cement formulations. As a result, the compressive and flexural strengths of the mortar containing purified PG increased from 33.4 and 7.8 MPa to 36.3 and 8 MPa, respectively, in comparison with mortars prepared with raw PG. |