Resource recycling of industrial waste phosphogypsum in cementitious materials: Pretreatment, properties, and applications

Each year, the global phosphate fertilizer industry produces an estimated 300 million tons of phosphogypsum (PG), of which only 15% is repurposed and the remaining 85% is stored near production sites, often in coastal areas that are prone to environmental degradation and natural disasters. Such accumulation poses severe risks to ecosystems and public health, exacerbating pollution and harming aquatic and terrestrial life. Addressing these challenges has become increasingly urgent, necessitating innovative and sustainable waste management strategies. The use of PG in producing eco-efficient cementitious materials offers a viable and environmentally sound strategy for its treatment and disposal. This study offers a detailed comparative analysis of various PG variants over the past decade (2014-2024), examining their chemical, physical, and radiological properties. We critically evaluate the pretreatment methods for PG and their incorporation into supplementary cementitious materials, assessing its impact on the workability, mechanical properties, shrinkage, and transport characteristics of PGbased cementitious composites (PBCMs). Additionally, we identify major knowledge gaps and recommend future research directions to improve the durability of PBCMs and develop novel PG-based materials that align with sustainable construction goals. This work aims to drive the evolution of sustainable construction practices, emphasizing the critical role and potential of PG in advancing green building technologies.