ADU转化为U_3O_8粉末的脱氟研究及机制分析  

Defluorination and Mechanism Analysis During Preparing U_3O_8 Using ADU

作　　者：唐向阳[1] 刘保金[1] 刘锦洪[1] 

机构地区：[1]中国核动力研究设计院反应堆燃料及材料重点实验室,四川成都610041

出　　处：《湿法冶金》2015年第3期233-237,共5页Hydrometallurgy of China

摘　　要：研究了ADU转化为U3O8粉末过程中的脱氟及动力学。结果表明:脱氟温度和脱氟气氛对U3O8粉末中氟质量分数影响很大,温度越高、水蒸气流量越大,对脱氟越有利;ADU中的氟主要以挥发性气体NH4F和铀氟化合物UO2F2形式存在,易除去,而残留的少量氟与铀氧化物结合成固溶体,很难去除;脱氟动力学行为验证了Lindman提出的氟在铀氧化物中以固溶体形式存在的观点;在850℃、70%H2O-30%N2气氛中脱氟150min以上,U3O8粉末中氟、氯质量分数均低于2μg/gU;工艺稳定可靠,满足生产医用同位素溶液堆的要求。T he paper describes the defluorination and mechanism during preparing U3 O8 using ADU . The results show that the defluorination temperature and atmosphere affect great fluorine content in U3O8 powder .The higher the temperature and the greater the water vapor flow ,the better defluoriation .The fluoride in ADU mainly exists as volatile gas NH4 F and UO2 F2 and is removed easily .But ,a small amount of residual fluorine combined with uranium oxides into solid‐solution is removed difficultly .The defluorination kinetics holds up Lindman’s view piont that residual fluorine exists in the form of solid‐solution .At 850 ℃ ,in 70% H2 O‐30% N2 atmosphere ,more than 150 min , fluorine and chlorine content in U3 O8 is less than 2 μg/gU .This process is steady and meets the requiements of the fluorine and chlorine content of medical isotopes solution reactor .

关 键 词：ADU 脱氟 U3O8 动力学 

分 类 号：TQ174.43[化学工程—陶瓷工业]