Synthesis of thorium tetrafluoride (ThF4) by ammonium hydrogen difluoride (NH4HF2)

• Main Authors: Che Nor Aniza Che Zainul Bahri, Aznan Fazli Ismail, Amran Ab. Majid
• Format: Article
• Language: English
• Published: Elsevier 2019-06-01
• Series: Nuclear Engineering and Technology
• Online Access: http://www.sciencedirect.com/science/article/pii/S1738573318304819

The present study aims to investigate the fluorination of thorium oxide (ThO2) by ammonium hydrogen difluoride (NH4HF2). Fluorination was performed at room temperature by mixing ThO2 and NH4HF2 at different molar ratios, which was then left to react for 20 days. Next, the mixtures were analyzed using X-ray diffraction (XRD) at the intervals of 5, 10, 15, and 20 days, followed by the heating of the mixtures at 450–750 °C with argon gas flow. The characterization of ThF4 was established using X-ray diffraction (XRD) and scanning electron microscopy–dispersion X-ray spectroscopy (SEM–EDX). In this study, ammonium thorium fluoride was synthesized through the fluorination of ThO2 at room temperature. The optimum molar ratio in synthesizing ammonium thorium fluoride was 1.0:5.5 (ThO2:NH4HF2) with 5 days reaction time. In addition, the heating of ammonium thorium fluoride at 450 °C was sufficient to produce ThF4. Overall, this study proved that NH4HF2 is one of the fluorination agents that is capable of synthesizing ThF4. Keywords: Thorium tetrafluoride, Thorium oxide, Ammonium hydrogen difluoride, Ammonium thorium fluoride