Recovery of Critical Elements (Dysprosium and Ytterbium) from Alkaline Process of Indonesian Zircon Tailings: Selective Leaching and Kinetics Study

Rare earth metals are important today, especially for heavy rare elements (HREEs). Dy and Yb, included in the HREE group, widely used permanent magnets sensors. On other hand, accumulated solid waste of zircon tailings is an environmental issue mineral processing. Valuable minerals such as (REEs) also remain tailings. This study aims to determine optimum conditions experimental parameters obtain appropriate kinetic model. The leaching process was carried out a flat bottom three-neck flask equipped with thermometer reflux condenser. Observation effect on recovery kinetics analysis obtained satisfactory results. In this study, Yb from REE-hydroxide using HCl solution afforded total 61.71% 74.55% respectively, at operating 1 M HCl, 60°C, 10 g/100 mL (solid-to-liquid ratio), 60 min (leaching duration), 150 rpm (stirring speed). It found that controlled by chemical reactions apparent activation energies 31.68 kJ/mol 11.95 leaching, respectively.