REE behavior and sorption on weak acid resins from buffered media

Rare Earth Elements (REEs) are of great importance to modern day societies. Although abundant, concentration of REE minerals in ores are generally quite low, with high concentration of impurities. To counteract this, selective extraction processes must be undertaken. Selective adsorption of REE from buffered media solutions on Purolite S910 and Amberlite IRC86 weak acid resins has been studied. Batch experiments have been carried out on solutions containing a selection of REEs, Y3+, Fe3+ and Al3+ in unbuffered media, malic acid, formic acid, acetic acid, alanine and lactic acid to determine the best extracting media. Isotherm behavior and extraction kinetics of IRC86 were determined for acetic acid media, at the most effective pH that was determined to be 4.38. The isotherms were conducted for La3+, Sm3+, Er3+ and Y3+ determining extraction maxima of 0.29, 0.34, 0.49 and 0.60 mmol L−1, respectively, with adsorption energies increasing with the same trend. Kinetic experiments determined that mid REEs were the fastest adsorption, with light REEs and heavy REEs displaying similar half-lives and Y3+ measuring the smallest half-life out of the studied ions.