Abstract: Coal material contains low-grade rare earth elements (REEs) that can be extracted using hydrometallurgical processes. This seminar discusses the findings and investigation on the leaching and precipitation behavior of rare earth elements covering different hydrometallurgical processes all the way from the mode of occurrence of REEs in coal to the production of marketable RE products. The leaching kinetics and reaction rate will be discussed including the activation energy for light and heavy rare earth elements extraction, the rate controlling mechanism occurred on the solid-liquid interface, and the solution stability of the leachate solution. The downstream process including multistage precipitation and redissolution, solvent extraction, and selective precipitation will be discussed. The purification of REEs using oxalate precipitation will be discussed including the solution speciation analysis and the effect of contamination ions on the REEs extraction efficiency and purity. The presentation will also give an overview of the status of the critical materials industry, the opportunities associated with the strategic vulnerabilities, and the prospective of critical material sourcing, mining, and recycling.
Bio: Xinbo Yang is an assistant research professor in department of Mining Engineering at the University of Kentucky. She received her Ph.D. in Mining Engineering from the University of Kentucky in 2019. Her expertise is in mineral processing and extractive metallurgy with specific research interests in rare earth element extraction and purification, solution chemistry and speciation, advanced fine particle separation, and mine waste treatment and reclamation. She has over 5 years of experience in the extraction and purification of rare earth elements from low grade sources and complex aqueous system and managed a rare earth pilot plant facility for two years. She has authored over 20 peer-reviewed journal publications and conference proceedings.