影响CaCl2-NaCl熔盐电脱氧法制备金属Zr的工艺条件

将氧化物转化为金属是熔盐电解精炼干法后处理氧化物乏燃料流程的关键步骤之一。在等摩尔CaCl₂-NaCl混合熔盐体系中，以石墨棒为阳极，采用高温烧结后的ZrO₂模拟UO₂开展了电脱氧制备金属Zr的FFC剑桥工艺条件优化。研究了工艺条件（槽电压、电解时间、烧结温度和电解温度等）对电脱氧制备Zr的影响。采用场发射扫描电子显微镜(SEM)和X射线衍射(XRD)分别分析了电解前后ZrO₂阴极的微观结构和物相组成。优化后的工艺条件为：电压3.4 V、电解时间12 h、烧结温度900 ℃和电解温度722 ℃。同时，研究结果表明, ZrO₂电脱氧还原为Zr时，存在中间产物CaZrO₃和ZrO。

Effects of Technological Conditions on Preparation of Metal Zr Using Electro-Deoxidation Method in CaCl2-NaCl Molten Salt

The conversion of oxides into metals is one of the key steps in the dry reprocessing of spent oxide fuel using the molten salt electrorefining method.In this study,in the CaCl₂-NaCl molten salt system,graphite rods were used as anodes,and the high-temperature sintered ZrO₂ flakes were simulated UO₂ cathode.Besides,the FFC Cambridge process conditions of electro-deoxidation to prepare metal zirconium in CaCl₂-NaCl molten salt were optimized.The effects of electrolysis process conditions(cell voltage,electrolysis time,sintering temperature,and electrolysis temperature,etc.)on the preparation of Zr by electro-deoxidation was studied systematically.SEM and XRD were utilized to analyze the microstructure and phase composition of the ZrO₂ cathode before and after electrolysis,respectively.The optimized process conditions are voltage of 3.4 V,electrolysis time of 12 h,sintering temperature of 900℃,and electrolysis temperature of 722℃.At the same time,the intermediate products CaZrO₃ and ZrO are found in the conversion of ZrO₂ into Zr.