Exploring the Chemical Kinetics of Rare Earth Element Separation under Thermal Conditions

Rare earth elements (REEs) are essential materials comprising 17 elements with broad applications in advanced technologies, especially in nuclear and industrial sectors. Dysprosium (Dy), for example, is used as a dopant in thermoluminescent dosimeter (TLD) crystals for radiation monitoring. REEs naturally occur in minerals such as monazite and xenotime, generally forming complex compounds. Previous research has emphasized purification, with precipitation considered an important preliminary step for element separation. This study investigates the precipitation of Praseodymium (Pr), Dysprosium (Dy), Neodymium (Nd), Cerium (Ce), and Lanthanum (La) at varying temperatures and times to determine rate constants and activation energies. The results showed that optimal conditions for Pr, Dy, and Nd precipitation were 60°C for 60 minutes, while Ce and La reached optimal precipitation at 40°C and 30°C, respectively, at 60 minutes. Kinetic analysis indicated that Pr, Ce, Nd, and La followed zero-order kinetics, whereas Dy followed first-order kinetics. Activation energies varied considerably, with Ce exhibiting the highest at 72.010 kJ/mol and Nd the lowest at 6.474 kJ/mol. This research presents a comparative kinetic analysis of multiple REEs under controlled temperature variation, offering valuable data for developing scalable and efficient REE recovery systems aligned with industrial innovation efforts.