文章编号:0253-9950(2012)05-0262-07TODGA-DHOA体系萃取金属离子Ⅰ.对Np(ⅣⅤ,Ⅵ)的萃取朱文彬李峰峰,叶国安李会蓉中国原子能科学研究院放射化学研究所,北京102413摘要:次锕系核素(主要为Am、Cm和Np)是放射性废物中长期放射性毒性的最大贡献体将这些次锕系核素从废物中去除后可以将必要的储存时间由原来的大于106年减少到不到103年。近年来二甘醇二酰胺(两个酰胺基团之间通过醚基连接)作为三齿试剂与金属离子配位得到了广泛的研究。在这类试剂中N,NN′,N′-四辛基-3-氧戊二酰胺(TODGA)被认为从高放废液(HLLW)中分离三价锕系和镧系具有较大的应用前景本工作以TODGA和N,N-二己基辛酰胺(DHOA)为萃取剂研究了以正十二烷为稀释剂,二者对Np(Ⅳ)、Np(Ⅴ)和Np(Ⅵ)的萃取行为主要考察了萃取剂浓度、HNO3浓度和NaNO3浓度的影响。结果表明:TODGA和DHOA对Np(Ⅳ)、Np(Ⅴ)囷Np(Ⅵ)的萃取分配比大小顺序均为:D(Np(Ⅳ))>D(Np(Ⅵ))>D(Np(Ⅴ))并且均对Np(Ⅴ)的萃取能力較小;TODGA/正十二烷体系中加入DHOA时,对Np(ⅣⅤ,Ⅵ)萃取具有一定的反协同效应;TODGA萃取Np(ⅣⅤ,Ⅵ)的方程式分别为:Np4+(aq)+4NO-aq+3TODGAorg?→NpNO343TODGAorg3()()()·()NpO+aq+NO-aq+TODGAorg?→NpO2NO3TODGAorg2()3()()()·()NpO2+aq+2NO-aq+2TODGAorg?→NpO2NO32()3()()()·()2TODGAorg2关键词:TODGA;DHOA;溶剂萃取;Np(ⅣⅤ,Ⅵ)中图分类号:TL241.12文献标志码:AExtractionofMetalIonsFromAqueousNitricAcidSolutionsWithTODGAandDHOAI.ExtractionofNp(ⅣⅤ,Ⅵ)IonsZHUWen-binLIFeng-feng,YEGuo-anLIHui-rongChinaInstituteofAtomicEnergy,P.O.Box275(26)Beijing102413,ChinaAbstract:Theminoractinides(MAmainlyAm,CmandNp)arethelargestcontributorstothelongtermradiotoxicityofthewaste.TheremovalofMAfromthewastewouldreducethenecessarystoragetimefrommorethan106yearstolessthan103years.Diamidesnamelythediglycolamides(containingetherlinkagebetweentwoamidegroups),havealsobeenstudiedfortheirextractionabilitytowardsminoractinidesastheyactastridentateligandstocomplexwiththemetalions.AmongdiglycolamidesrecentlydevelopedN,NN′,N′-tetraoctyldiglycolamide(TODGA)hasbeenidentifiedasoneofthemostpowerfulextract-antbeingconsideredforthepartitioningoftrivalentactinidesandlanthanidesfromHLLW收稿日期:2012-05-02;修订日期:2012-06-08作者简介:朱文彬(1974—)男,四川简阳人副研究员,硕士核燃料循环与材料专业第5期朱文彬等:TODGA-DHOA体系萃取金属离子Ⅰ.对Np(Ⅳ,ⅤⅥ)的萃取263solutions.So,inthepresentpapertwoextractionreagents,TODGAandNN-dihexyl-octamide(DHOA)havebeenusedasextractantsforextractionNp(Ⅳ,ⅤⅥ)ionsfromaqueousnitricacidsolutions.Theeffectsofconcentrationofthenitricacid,salting-outagentsinaqueousandtheextractantinordanicphaseondistributionratiosareexamined.There
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