Upgrading Phosphogypsum for Uses as Construction Materials

Over 70% of the world’s phosphate rock product is consumed by the “wet” process for production of phosphoric acid, which is mainly used for fertilizer manufacturing. In this process, roughly 5 tons of phosphogypsum (PG) are generated per ton of P2O5 produced. On that basis, at least 150 million tons of PG are being added annually to the world stockpile of billions of tons. Although the Florida style stacking with lining is the state-of- art PG disposal practice and may stay dominant in the phosphate industry for years to come, this practice is neither cost effective nor environmentally sound. The phosphate companies, particularly those in China, are under great pressure to find uses for PG quickly. Use of PG as construction materials could ease the problem significantly. However, due to its high content of P and other gangue materials such as fluorides and silica, this line of PG use is severely limited. Under this research program, a combination of gravity separation with flotation produced an upgraded PG acceptable for many construction uses. The results summarized in Table 1 indicates this.Please click Additional Files below to see the full abstract.