Mineralogical characterization of Indonesian rare earth elements from secondary resource (zircon tailings)

Abstract

The increase in demand for products based on rare earth metals has increased because of their recent surge in usage. Additionally, primary sources of rare earth metals, such as bastnaesite, are scarce. Therefore, it is necessary to characterize secondary sources to explore the potential of other rare earth metal sources to overcome their scarcity. This study utilizes zircon tailings from zircon processing in Indonesia, which are the result of magnetic separation of zircon sand (magnetic particles). An analysis of the elemental and mineral composition, as well as the particle size distribution of the tailings, was conducted. The results revealed a significant ZrO₂ composition of 10.3%, with 14.11% CeO₂ and 11.47% Y₂O₃ as the major oxides. Additionally, ThO₂ was present at 2%, which could be considered for the processing of zircon tailings for rare earth metal refinement because of its radioactive properties. The mineral phases indicate that the tailings consist mainly of xenotime, monazite, and zircon. Additionally, a rare earth metal-bearing mineral, cerianite, is present. The concentration of rare earth metals is greater for larger particles, whereas that of zircon is greater for smaller particles. These findings can be used to determine the next steps in the rare earth metal purification or extraction process.