(658i) Membrane and Sorbent Based Recovery of Rare-Earth-Elements (REE) from Acid Mine Drainage Sludge

This project presents results from a staged membrane-based and sorbent based, bench-scale system to extract rare earth elements (REEs) from acid mine drainage (AMD) sludge generated as part of coal mining activities in the United States. The treatment approach includes a review of feedstock characterization and results from separation, concentration, and ultimate recovery of REEs from AMD. Sludge samples from four AMD site(s) were characterized for REE concentration, dissolved metals concentration, and key water-quality characteristics. Each individual process component were tested with water samples to optimize performance. The work demonstrates proof-of-concept experiments at the bench scale with respect process parameters such as water chemistry, nanofiltration membrane performance in monovalent/multivalent separation, affinity media chemistry on the final recovery of REE.