Recovery of Some Rare-Earth Elements by Sorption Technique onto Graphene Oxide

Abstract

In this work, graphene oxide (GO), prepared using the Hummers method, is physically characterized and used for rare-earth metals recovery from monazite ores. Batch study for sorption of 152+154Eu radionuclide onto GO carried out to assess the optimum reaction parameters for recovery process. The optimum pH is 2.09, the equilibrium time achieved after 5 h, humic acid enhances the sorption efficiency but if its concentration increases it opposes the sorption process. The kinetic reaction mechanism is regulated by pseudo-2nd order and the sorption isotherms show Langmuir applicability. The maximum sorption capacity for 152+154Eu at 20 °C is 59.81 mg g−1. Desorption studies were performed to determine a proper eluent with a suitable concentration for the recovery process and 0.1 M HCl was selected as an efficient eluent. The sorption process is favorable and endothermic. Finally, GO is used as a sorbent for rare-earth elements accumulated in monazite ore. The sorption efficiency of REE is 69.03% with initial concentration 1149.57 mg L−1 at monazite leachate and the recovery percentage is 20.32%. These results promised the use of GO for REE recovery from monazite ore. Graphical Abstract: [Figure not available: see fulltext.]