Y(III) Ion Migration in AlF₃–(Li,Na)F–Y₂O₃ Molten Salt

Abstract

In this study, three slots containing an anode chamber, a cathode chamber, and a middle pole chamber were designed by applying the Hittorf method, and a two-way coupling model of the flow field and electric field was established using the COMSOL system. The electric field distribution in the constructed model was simulated, and the model reliability, boundary conditions, and related parameters were verified. A three-chamber tank was utilized to investigate the migration numbers change rule and migration mechanism of Y(III) ions in the AlF3–(Li,Na)F system. The migration number of Y(III) ions in the AlF3–(Li,Na)F–Y2O3 molten salt linearly increased from 0.70 to 0.80 with an increase in temperature from 900 to 1000 °C. When the (Li,Na)F/AlF3 molar ratio was between 2.0 and 2.5, the migration number of Y(III) ions was relatively constant, and its average value was approximately 0.75. Meanwhile, at (Li,Na)F/AlF3 molar ratios higher than 2.5, the migration number of Y(III) ions linearly decreased from 0.75 to 0.45. Finally, in the current density range of 1.0–2.0 A/cm2, the migration number of Y(III) ions increased almost linearly from 0.65 to 0.85.

Keywords

• molten salt
• Y(III) ion
• Hittorf method
• migration number
• three-chamber tank