Study on the fluorination of dysprosium oxide by ammonium bifluoride for the preparation of dysprosium fluoride

In this report, dysprosium fluoride (DyF3) - a material for the preparation of dysprosium (Dy) metal was prepared by the fluorination of dysprosium oxide (Dy2O3) by ammonium bifluoride (NH4HF2) reagent. The effect of reaction time and temperature on the formation of dysprosium fluoride salt has been studied. The phase composition and crystal structure of the obtained products were analysed by X-ray diffraction (XRD). Thermal analysis techniques were applied to determine the temperature range of the fluorination. Scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS) was used for external morphology observation and chemical elemental composition analysis. The results showed that the high purity phase of DyF3 was formed at the conditions: reaction time and temperature of >1 h and >350oC, respectively. The product is available for the preparation of Dy metal by metallothermic reduction.