叔胺N_(235)萃取盐酸时酸度对产生第三相的影响  

Effect of HCl Concentration on Formation of Third-phase in N_(235)-C_(12)H_(26)-HCl Solvent Extraction System

作　　者：谢琦莹[1] 陈景[1] 杨项军[1] 

机构地区：[1]云南大学化学科学与工程学院,昆明650091

出　　处：《无机化学学报》2008年第6期897-901,共5页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.50374060;50764008)资助项目

摘　　要：本文研究了三烷基胺N235-C12H26-HCl萃取体系,在无改性剂TBP(磷酸三丁酯)和含20%TBP两种情况下,初始HCl浓度对HCl萃取率、第三相体积和第三相电导率的影响。发现无TBP时,萃取入有机相的HCl按两阶段形式进入第三相。在nHCl(o)/nN235(o)≤1时,形成的第三相萃合物为R3N·(H2O)m·HCl(m<3)。在nHCl(o)/nN235(o)>1时,萃合物组成接近R3N·(H2O)m·2HCl。第三相的体积及电导率变化均在nHCl(o)/nN235(o)=1附近出现拐点。有机相含20%TBP后,在cHCl(init)≤4.0mol·L-1范围不出现第三相,cHCl(init)≥5.0mol·L-1则再次出现第三相,此第三相的组成推测为R3N·(H2O)m·HCl及TBP·(H2O)m·HCl两种离子溶液的混合物。The formation of the third-phase in N235-C12H26-HCl extraction system was investigated. The influence of the initial HCl concentrations on HCl percentage extractions, and on the variations of the third phase volumes and its conductivities were discussed by comparing systems with or without the addition of tri-n-butyl phosphate（TBP） as modifier. It is demonstrated that, without the addition of TBP, the HCl molecules extracted into the organic phase enter the third phase according to two different stages： （1） when nHCl（o） / n≤1, the chemical composition of the third phase is R3N·（H2O）m·HCl （m〈3）; whereas （2） when nHCl（o） / n〉1, the third phase is R3N·（H2O）m·2HCl. The variati-ons of the phase volumes and those of the conductivities of the third phases appear an inflexion around nHCl（o） / n of 1∶1. With the addition of 20% TBP into the organic phase, the third-phase disappears when cHCl（init）≤4.0 mol·L^-1, while appearing again when cHCl（init）≥5.0 mol·L^-1. It is assumed that the third phases in systems is a mixture of two ionic liquids R3N·（H2O）m·HCl and TBP·（H2O）m·HCl.

关 键 词：溶剂萃取 叔胺(N235) 盐酸 第三相 

分 类 号：O611.662[理学—无机化学]