摘要
本研究讨论了2,6-bis（5,6-dibutyl-1,2,4-triazin-3-yl）pyridine （isoBu-BTP）作为萃取剂在一种常见的疏水性咪唑类离子液体1-乙基-3-甲基咪唑双三氟甲磺酰亚胺盐（[C2mim][NTf2-]）中对硝酸溶液中几种稀土元素（Y、Nd、Eu、Dy）的萃取行为,其中重点考察对Dy的萃取.研究结果表明：与传统有机溶剂体系相比,离子液体萃取体系在低酸度（0.01～0.1mol/L）下对稀土元素有良好萃取效果,特别是对Dy显示了良好的选择性,另一方面,利用高酸（＞3 mol/L）可以进行反萃;本研究以对Dy的萃取为例,通过双对数法,推算出Dy3＋与isoBu-BTP的化学当量比为1∶2.4.由此推测Dy3＋的萃取机理可能分为两方面,一方面是多数Dy3＋与isoBu-BTP形成摩尔比为1∶3的配合物,另一方面是小部分Dy3＋与[C2mim]＋进行阳离子交换被离子液体本身萃取,从而证明了该体系中离子液体具有协同萃取的效应.
Hydrophobic ionic liquids are promising extractio separation of metal ions. In current research, the extraction n media in solvent extraction behavior of several rare-earth metals（Y, Nd, Eu, Dy） from nitric acid solution was studied using a novel extracting system based on hydrophobic ionic liquid. The novel extracting system is made up of 2,6-bis（5,6- dibutyl-l,2,4-triazin-3-yl） pyridine（isoBu-BTP）, which acted as extractant, can separate lanthanides and minor actinides effectively in nitric acid solution. 1-ethyl-3-methylimidazolium bis（trifluoromethylsulfonyl）imide （[C2mim-][NTf2]）, which acted as extraction medium, shows a great solubility against isoBu-BTP. The influence of the concentration of nitric acid, the concentration of extractant and the stripping condition was investigated in detail. It was found that the isoBu-BTP/[-C2mim~ ENTf2~ extracting system is favorable to extract rare- earth metals at low acidity condition （d0.1 tool/L）, and back-extract at high acidity condition （）3 mol/L）. In addition, Dy was found to be selectively extracted in current extracting system. The extraction mechanism for the extraction of Dya＋ was also discussed. A lg-lg plot of the D（Dy） values versus isoBu-BTP concentration gave a straight line with a slope of 2.4. It is suggested that most Dy from aqueous phase was extracted by BTP, which can form a 3 ： 1 molar complex with Dy3＋ ; while a small quantity of Dy was extracted by ionic liquid itself. The cation exchange and co-extraction, which induced from ionic liquid, functioned to extraction and resulted into such stoichiometry mentioned above.
出处
《核化学与放射化学》
CAS
CSCD
北大核心
2014年第4期193-199,共7页
Journal of Nuclear and Radiochemistry
基金
国家自然科学基金资助项目(91126006)
上海高校特聘教授(东方学者)岗位计划资助项目
