四氟化铀和四氟化钍的高温水解
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摘要
为适应钍基熔盐堆核燃料水法后处理的需求,需将乏燃料中难溶的氟化物转化为相应的氧化物形式,因此提出了高温水解的方法来实现这一目的。研究了UF4、ThF4在不同反应温度和反应时间下的高温水解行为,对其水解产物进行了结构表征和溶解实验的研究。结果表明,UF4、ThF4分别在300℃和350℃即可全部转化为相应的氧化物UO2.25和ThO2。溶解实验结果表明,二者的高温水解产物较易溶解在3mol/L HNO3和Thorex试剂中。
To meet the needs of the aqueous-reprocessing of used fuel from thorium molten salt reactor,the insoluble fluorides need to be converted into their corresponding oxides form.To realize this,apyrohydrolysis method was proposed.The pyrohydrolysis behavior of UF4 and ThF4 under different temperature and time was studied,and the structural characterization of the pyrohydrolysis products and the dissolution tests of the products were performed.The results show that,UF4 and ThF4 are entirely converted into their corresponding oxides UO2.25 and ThO2 at 300℃ and 350℃.The results of the dissolution tests show that the pyrohydrolysis products of both UF4 and ThF4 can easily dissolved in 3mol/L HNO3 and Thorex solution,respectively.
To meet the needs of the aqueous-reprocessing of used fuel from thorium molten salt reactor,the insoluble fluorides need to be converted into their corresponding oxides form.To realize this,apyrohydrolysis method was proposed.The pyrohydrolysis behavior of UF4 and ThF4 under different temperature and time was studied,and the structural characterization of the pyrohydrolysis products and the dissolution tests of the products were performed.The results show that,UF4 and ThF4 are entirely converted into their corresponding oxides UO2.25 and ThO2 at 300℃ and 350℃.The results of the dissolution tests show that the pyrohydrolysis products of both UF4 and ThF4 can easily dissolved in 3mol/L HNO3 and Thorex solution,respectively.
引文
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[5]Warf J C,Cline W D,Tevebaugh R D.Pyrohydrolysis in determination of fluoride and other halides[J].Anal Chem,1954,26(2):342-346.
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[7]张黎辉,陈贵福.高温水解-离子色谱法测定核电级二氧化铀中氟、氯、溴、硫[J].湿法冶金,2000,19(1):51-56.
[8]刘雪峰,刘晶,宋党育,等.用高温水解-离子色谱法研究贵州煤中氟质量分数[J].华中科技大学学报(自然科学版),2008,36(4):84-87.
[9]卢鸿琏.GB 11844—89二氧化铀粉末和芯块中氟的测定:高温水解-离子选择性电极法[S].北京:中国标准出版社,1990:9-12.
[10]Iwasaki M,Ishikawa N.Pyrohydrolysis reactions of UF4and UO2F2effect of oxygen on reactions[J].J Nucl Sci Technol,1983,20(5):400-404.
[11]康仕芳,赵君.UF4水解反应动力学研究[J].核化学与放射化学,1998,20(4):202-206.
[12]Bulko J B,Nachtrab W T.Method for producing uranium oxide and a non-radioactive fluorine compound from uranium tetrafluoride and a solid oxide compound:the United States,5,918,106[P].1999-06-29.
[2]秋穗正,张大林,苏光辉,等.新概念熔盐堆的固有安全性及相关关键问题研究[J].原子能科学技术,2009,43(增刊):64-75.
[3]Amano O,Yasui K,Sasahira A,et al.FLUOREX reprocessing technology with uranium removal from spent fuel by fluorination-volatilization reaction of uranium[J].J Nucl Sci Technol,2002(Suppl 3):890-893.
[4]Kani Y,Sasahira A,Hoshino K,et al.New reprocessing system for spent nuclear reactor fuel using fluoride volatility method[J].J Fluorine Chem,2009,130(1):74-82.
[5]Warf J C,Cline W D,Tevebaugh R D.Pyrohydrolysis in determination of fluoride and other halides[J].Anal Chem,1954,26(2):342-346.
[6]张耀玲,牛励珺,许君政,等.三氧化铀中微量氟、氯、溴的测定[J].核化学与放射化学,2007,29(4):220-225.
[7]张黎辉,陈贵福.高温水解-离子色谱法测定核电级二氧化铀中氟、氯、溴、硫[J].湿法冶金,2000,19(1):51-56.
[8]刘雪峰,刘晶,宋党育,等.用高温水解-离子色谱法研究贵州煤中氟质量分数[J].华中科技大学学报(自然科学版),2008,36(4):84-87.
[9]卢鸿琏.GB 11844—89二氧化铀粉末和芯块中氟的测定:高温水解-离子选择性电极法[S].北京:中国标准出版社,1990:9-12.
[10]Iwasaki M,Ishikawa N.Pyrohydrolysis reactions of UF4and UO2F2effect of oxygen on reactions[J].J Nucl Sci Technol,1983,20(5):400-404.
[11]康仕芳,赵君.UF4水解反应动力学研究[J].核化学与放射化学,1998,20(4):202-206.
[12]Bulko J B,Nachtrab W T.Method for producing uranium oxide and a non-radioactive fluorine compound from uranium tetrafluoride and a solid oxide compound:the United States,5,918,106[P].1999-06-29.