Study on preparation and application of NaCl-KCl-CsCl-Cs₂ZrCl₆ composite electrolyte

Abstract

Preparing zirconium chloride composite salts such as Cs2ZrCl6 can replace highly volatile ZrCl4 for studying molten salt electrolytic refining zirconium. The NaCl-KCl-CsCl-Cs2ZrCl6 composite electrolyte was prepared using ternary molten salt with a molar ratio of NaCl: KCl: CsCl=30: 24.5: 45.5 and ZrCl4 as raw materials. According to thermodynamic analysis, ZrCl4 preferentially reacts with CsCl to form Cs2ZrCl6 with strong stability. X-ray diffraction analysis showed that the main phase of the product was Cs2ZrCl6. ICP-DSC analysis showed that the conversion rate of ZrCl4 to Cs2ZrCl6 reached 99.68%. To verify the properties of this electrolyte, it is applied to molten salt electrolytic refining sponge zirconium. Studies have shown that this electrolyte system obtains dendrite zirconium products with a maximum grain size of 6.29mm, a system with more application prospects.