Leaching recovery of rare earth elements from the calcination product of a coal coarse refuse using organic acids

Due to the increasing criticality of rare earth elements (REEs), it has become essential recover REEs from alternative resources. In this study, systematic leaching tests were performed on calcination product a coal coarse refuse using hydrochloric acid and different types organic as lixiviants. Experimental results show that recovery REEs, especially heavy (HREEs) scandium (Sc), is improved by selected acids. Citric dl-malic afford best performances; whereas, malonic acid, oxalic dl-tartaric are inferior acid. Results zeta potential measurements solution chemical equilibrium calculations more likely adsorbed surface calcined material compared with citric The adsorption may reduce effective concentration species in and/or increase amount surface, thereby impairing recovery. Compared light (LREEs), stronger HREEs observed electro-kinetic test results. This finding explains why acids impose positive impact HREEs. By complexing HREEs, can keep metal ions improve Sc3+ lowest other REEs. Therefore, rather than complexing, anionic play function solubilizing Sc solid, which similar hydrogen ions.