A Comprehensive Review on Occurrence and Processing of Phosphate Rock Based Resources- Focus on REEs

ABSTRACTABSTRACTIn general, the phosphatic rock contains around 0.05 wt% rare earth elements (REEs). The global commercial phosphatic rock output is anticipated to obtain 250 million tons per year, making phosphate rocks a significant source of REEs. The review discusses the geological aspects of phosphate rocks, their availability, and methodologies to convert them to phosphoric acid and ultimately to phosphogypsum. Phosphogypsum (PG) is a high-volume by-product of phosphate-based chemical industries that produce phosphoric acid. Because of the low radioactivity of radionuclide contaminants, roughly 85% of PG is stored in open fields. These PG stacks require enormous land areas, cause substantial upkeep expenses, and may create major environmental damage. Apart from the detailed analysis of metal worth in phosphogypsum, the efforts put forth by researchers in recovering valuable rare earth elements from PG have been discussed. Additionally, the processes for metal separation and purification are also discussed in vogue.KEYWORDS: Phosphate rockphosphoric acidphosphogypsumREE distributionextraction AcknowledgementsThe authors acknowledge the support from Science and Engineering Research Board (SERB) via Grant No. CRG/2019/005849Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThe work was supported by the Science and Engineering Research Board [CRG/2019/005849].