Advancing Selective Extraction: A Novel Approach for Scandium, Thorium, and Uranium Ion Capture.

The potential use of thorium (Th) and uranium (U) as nuclear fuels underscores the importance of developing materials for their sustainable recovery. The production of Th and U requires the separation of these elements from rare-earth elements (REEs) as they often coexist in various feedstocks. Equally crucial is efficiently isolating scandium (Sc) from REEs, considering its high-value status and pivotal role in advanced alloy technologies. This study introduces a new selective ligand-functionalized silica sorbent for extracting Sc, other REEs, Th, and U from solutions with varying pH and elemental compositions. The functionalized sorbent exhibits exceptional selectivity for Sc ions at pH 4 across solutions containing 3-20 elements. It also shows excellent selectivity for Th at pH 2 in 18- and 20-element solutions and substantial selectivity for U in 18- and 20-element solutions at pH 4. Additionally, it efficiently adsorbs neodymium (Nd), dysprosium (Dy), and lanthanum (La) in Sc-free solutions with a given preference for Nd. The ligand-functionalized sorbent successfully undergoes ten cycles of reuse which along with its enhanced recovery performance toward targeted elements highlights its industrial application potential.