Extraction of Some Rare Earth Elements Using an Environmental Friendly Method

Document Type : Original research papers

Authors

Nuclear Materials Authority

Abstract

In this study, the equilibrium and kinetic characteristics of natural clinoptilolite in the HCl medium were determined. Optimized adsorption parameters were studied in detail, including pH, contact time, concentration, temperature, and eluting agents. Under optimal conditions, the practical adsorption capacity of rare earth elements on treated clinoptilolite reaches 50 mg/g, closely matching the Langmuir isotherm value of 53.4 mg/g. Adsorption kinetics and isotherm models were analyzed to describe the adsorption behavior of rare earth elements on natural clinoptilolite. The adsorption behavior aligns with both the pseudo-second-order reaction model and the Langmuir isotherm. Clinoptilolite regeneration reached 93.4% effectiveness using 0.5 M HCl. The applied ore was a monazite mineral, which was digested by a hydrothermal process. Under suitable extraction conditions of pH 1.0 and a contact time of 120 minutes, the extraction process was carried out at room temperature. Subsequently, elution was conducted in two stages: first, using 0.2 M EDTA, and second, using 0.5 M HCl for complete elution, followed by precipitation using sodium hydroxide.

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