Phosphogypsum-based building materials: Resource utilization, development, and limitation

Phosphogypsum (PG) is a major industrial waste emitted during phosphate production. Facing the environmentally risky challenges posed by PG emissions and stockpiles, a review of the state of PG resource utilization in civil engineering and searching for new ways to utilize PG to improve the utilization rate are necessary. Therefore, this paper compared the chemical composition and pretreatment methods of PG from different sources and outlined the application of PG-based building materials, including gypsum products, cement-based materials, and road materials. It was found that there are differences in the chemical composition and physical properties of PG due to differences in phosphate mines and production processes, which affected the way it was pretreated and applied. Currently, thermal treatment and synergistic treatment by various means are effective methods for cleaning PG, and future treatment processes should be developed to highly efficient, and low cost. PG-based building materials positively contribute to recovering PG and promoting resource recycling, but environmental safety and long-term stability need to be explored. In addition, the importance, limitations, and development trends of applying PG-based building materials were discussed. Future research focuses on solid waste-based cementitious and mineralized materials to inform harmless, high-value and large-scale utilization of PG.