The Chemical Behavior of the Different Impurities Present in Phosphogypsum: a Review

Phosphogypsum (PG) is an acidic by-product that is created during the production of phosphoric acid using the sulfuric acid route. The management of PG poses a significant environmental challenge worldwide due to its large quantity and chemical composition. While PG primarily consists of calcium sulfate dihydrate, it also contains various impurities such as phosphorus, fluoride, heavy metals, and radionuclides. These toxic impurities, when present in high concentrations, can have adverse effects on the environment and human health. In this review, we provide a detailed examination of the behavior of the most abundant impurities found in PG. Furthermore, we discuss the factors that influence the presence of different types of impurities in PG. Understanding the overall behavior of these impurities is crucial for selecting appropriate environmental methods for PG management and identifying suitable avenues for its valorization.