Extraction of Some Rare Earth Elements Using an Environmental Friendly Method

Rare earth elements extraction has been becoming one of the topics interests to researchers recently. Rare earth elements extraction by an environmental method using natural clinoptilolite and treatment clinoptilolite in an HCl medium. The equilibrium, kinetic properties and the optimized parameters of sorption studied in detail for extraction include pH, stirring time, primary concentration, temperature, and eluting agents. After adapting the optimal conditions, the treated clinoptilolite's practical sorption capacity for rare earth elements reaches 50 mg/g, which is near to the Langmuir isotherm value of 53.4 mg/g. The adsorption behavior of rare earth elements on natural clinoptilolite was examined using a variety of adsorption kinetics and isotherm models; the results demonstrated alignment with the Langmuir isotherm and the pseudo-second-order reaction model. Clinoptilolite elution achieved 93.4% effectiveness using 0.5 M HCl. The ore used was monazite, processed through a hydrothermal digestion method. The extraction process was carried out for rare earth elements on natural clinoptilolite under optimal conditions pH 1.0, a contact time of 120 minutes, and at room temperature. Elution was performed in two stages: initially with 0.2 M EDTA and subsequently with 0.5 M HCl for complete elution, followed by precipitation using sodium hydroxide.