|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||REWAS 2022: Recovering the Unrecoverable
||Leaching of Rare Earth Elements from Phosphogypsum Using Mineral Acids
||Sicheng Li, Monu Malik, Gisele Azimi
|On-Site Speaker (Planned)
Rare earth elements (REEs) are critical metals for modern and emerging green technologies. The increasing demand and limited supply of them have sparked the research on the recovery from secondary resources. The current study is focused on developing a hydrometallurgical process for the extraction of critical REEs from waste product from fertilizer manufacture (phosphogypsum, PG), and on elucidating the mechanism of the process. Three types of mineral acids are used for the leaching, and systematic study is utilized to assess the effect of operating parameters and to determine the optimum operating conditions. The thermodynamic modeling and solubility investigation show the strong correlation between phosphogypsum solubility and leaching efficiency, and the mechanism behind the leaching process is explored. Characterization results indicate that the REEs can exist as isomorphous substitutions and/or separate phases inside PG crystal. Based on these results, destruction of PG lattice and dissolution is required to achieve improved extraction.