As a typical uranium oxide, the electrochemical behaviors of U₃O₈ in molten salt have attracted many research endeavors, but its dissolution behavior and related mechanism in molten salt has been less well understood. In this work, we reported the dissolution of U₃O₈ in LiCl-KCl eutectic with the assistance of NH₄Cl, which has potential significance for the pyrochemical reprocessing of spent oxide fuels. The spectroscopic techniques such as fluorescence emission spectroscopy, UV-Vis absorption spectroscopy, and X-ray Absorption Fine Structure (XAFS) were used to determine the chemical species during the dissolution process of U₃O₈. The results show that U₃O₈ can be completely dissolved in molten salt under the air atmosphere, and it exists in the form of [UO₂Cl₄]²⁻. In contrast, under an argon atmosphere, the soluble [UO₂Cl₄]³⁻ and insoluble UO₂ were detected as the main products.

作为一种典型的铀氧化物，U ₃ O ₈在熔融盐中的电化学行为吸引了许多研究努力，但其在熔融盐中的溶解行为及其相关机理尚未得到很好的了解。在这项工作中，我们报道了借助NH ₄ Cl可以将U ₃ O ₈溶解在LiCl-KCl共晶中，这对于废氧化物燃料的热化学后处理具有潜在的意义。光谱技术，例如荧光发射光谱，紫外-可见吸收光谱和X射线吸收精细结构（XAFS）被用来确定U ₃ O ₈溶解过程中的化学种类。结果表明，U₃ O ₈可以在大气中完全溶解在熔融盐中，并且以[UO ₂ Cl ₄ ] ^2-的形式存在。相反，在氩气氛下，可溶的[UO ₂ Cl ₄ ] ^3-和不溶的UO ₂被检测为主要产物。