【作者】 范树娟；

【导师】 贾琼；

【作者基本信息】 吉林大学 ， 分析化学， 2012， 硕士

【摘要】 本论文围绕协同萃取技术在稀土元素及稀有元素（镓、铟）萃取分离中的应用进行了一系列的研究。近年来，稀土元素及稀有元素（镓、铟）在高科技领域的应用受到了越来越多的关注。例如，现在镓和铟越来越多的应用于半导体材料如InP和GaAs中。而稀土元素的研究领域更加广泛，包括荧光材料、玻璃制品、激光以及陶瓷材料等领域。但是，由于稀土元素之间有着相似的化学性质和物理性能，而镓铟处于同一主族，化学性质也非常相似，所以它们之间的分离都比较困难。随着高纯化稀土元素和镓铟的需求越来越大，金属元素之间的分离和纯化受到了更大的关注。协同萃取是溶剂萃取的一个分支，已经广泛的用于金属元素的萃取和分离中。协同萃取不仅能提高萃取效率，增加萃取络合物的稳定性，而且能增强萃取的选择性。本工作将CA100作为主要的萃取剂，与其他类型的萃取剂组成混合体系萃取稀土元素和镓铟。首先，考察了混合体系CA100和2,2’-联吡啶（bipy）的正庚烷溶液在硝酸介质中对稀土元素的萃取性能。结果显示，CA100和bipy的混合体系对所有的稀土元素均具有协同萃取效应。以重稀土元素钬为例，研究了协同萃取反应的机理。CA100和bipy体系的协同萃取的萃合物为Ho（NO3）2HA2B，而CA100单独萃取时的萃合物为HoH2A5。CA100和bipy的混合体系对稀土元素呈现了不同的协同萃取效应，而且根据分离稀土可知这一混合体系可以用于分离Y和其他稀土元素。其次，考察了盐酸介质中CA100与其他四种有机萃取剂三烷基胺（N235）、二甲庚基乙酰胺（N503）、二甲庚基乙酰胺（N503）、三烷基氧化膦（Cyanex923）对镓铟的萃取分离。这四种混合体系对镓铟呈现出不同萃取反应性能。相对于CA100的单独萃取，只有CA100＋C923的混合体系对镓和铟有更高的萃取分离能力。因此，在萃取分离条件合适的情况下，CA100+C923的混合体系可以用于镓铟的实际分离中。另外，在所有混合体系中只有CA100+N235的混合体系对铟具有协同萃取效应。实验中进一步利用斜率法和恒摩尔法探讨了萃取反应的机理。并且测定了CA100单萃体系和CA100＋N235的混合体系的萃合物分别为InCl₂HA_2（o）和InCl₂H₃A₄B。更多还原

【Abstract】 (Ⅲ) and indium （Ⅲ）. In recent years, rare earth elements （REEs）, gallium （Ⅲ） andindium （Ⅲ） received more and more attention in high-technology. For example,gallium （Ⅲ） and indium （Ⅲ） are used as semiconductor materials such as InP orGaAs. REEs are applied to phosphors, glass, laser, ceramic technology and so on.However, the mutual separation of REEs is widely recognized to be difficult becauseof their similar physical and chemical properties. And also, the two metals of gallium（Ⅲ） and indium （Ⅲ） show similar chemical behaviors.With the increasing demand for high purify REEs gallium （Ⅲ） and indium （Ⅲ）,the separation and purification of these metal ions have gained considered attention.As a branch of solvent extraction, sysnergistic extraction has become a commonmethod for the extraction and separation of metal ions. It can not only enhance theextraction efficiency and the stability of extracted complexs, but also improve theextraction selectivity. In the present work, sec-nonylphenoxy acetic acid （CA100） wasselected as the main extractant.Firstly, the synergistic solvent extraction of REEs with mixtures of CA100and2,2’-bipyridyl （bipy） in n-heptane from nitrate medium have been studied. Themixtures of CA100and bipy have significant synergistic effects on all the REEs.Holmium （Ⅲ） was selected as the example to investigate the extraction mechanism.The extracted compound is determined asHo（NO₃）₂HA₂B with the mixture instead ofHoH2A5, which is extracted by CA100alone. The mixtures exhibit differentextraction effects on different REEs. Furthermore, the mixtures of CA100with bipyare proved to have great potential for the separation of Y from lanthanoids accordingto the separation factors.Secondly, the synergistic extraction of gallium （Ⅲ） and indium （Ⅲ） fromchloride medium with mixtures of CA100and other organic extractans, includingtrialkyl amine （N235）, N,N-di（1-methyl-heptyl） acetamide （N503）, tributyl phosphate（TBP）, and tiralkyl phosphine oxide （Cyanex923） has been investigated. The mixturesexhibit different extraction effects on gallium （Ⅲ） and indium （Ⅲ）. Compared withsingle CA100system, only CA100＋C923mixtures have higher separation ability ofgallium （Ⅲ） and indium （Ⅲ）. Therefore, CA100＋C923can be considered for theseparation of the two metal ions at the appropriate ratio of the extractants. Synergisticeffects are only found when indium （Ⅲ） is extracted with mixtures of CA100andN235. The methods of slope analysis and constant mole are used for the determinationof the reaction. The extracted complexes with CA100and CA100＋N235aredetermined asInCl₂HA_2（o）,andInCl₂H₃A₄B, respectively.更多还原