稀释剂对N,N-二丁基十二酰胺萃取硝酸平衡的影响

本文研究了新萃取剂Ｎ，Ｎ二丁基十二酰胺（ＤＢＤＯＡ）萃取硝酸的机理。考察了不同稀释剂如：二甲苯、甲苯、四氯化碳、正辛烷、苯、环己烷、氯仿等对萃取平衡的影响，分析了萃取有机相的红外光谱。得到在不同稀释剂中萃取反应均为：ＨＮＯ３＋ＤＢＤＯＡ（０）＝ＨＮＯ３·ＤＢＤＯＡ（０）利用不同的稀释剂参数与萃取平衡常数进行了关联，发现任一参数都难以定量描述稀释剂的影响。     

HEH[EHP]萃取铬的研究

本文用分配法研究了以正己烷、环己烷、苯和氯仿作稀释剂时HEH[EHP]对Cr(Ⅲ)的萃取,提出了萃取反应平衡式及平衡常数;对在不同稀释剂中HEH[EHP]萃取能力发生变化的现象作于讨论。     

在不同稀释剂中二(2－乙基己基)磷酸萃取Ni(Ⅱ)的热力学

研究了在不同稀释剂如苯、甲苯、正己烷、环己烷、四氯化碳、氯仿中萃取剂浓度、水相酸度以及温度对二(2-乙基己基)磷酸萃取Ni(Ⅱ)的平衡的影响,借助萃合物红外光谱,确定了萃合物组成和萃取反应机理。讨论了稀释剂的影响,利用多参数方程将萃取平衡常数以及分配比与稀释剂的物理常数和经验参数进行了定量关联。     

不同稀释剂中N,N,N′,N′-四丁基-3-氧戊二酰胺从硝酸介质中萃取Gd(Ⅲ)离子的研究

在不同稀释剂体系中研究了N,N,N′,N′-四丁基-3-氧戊二酰胺(TBDGA)从硝酸介质中萃取Gd髥离子的性能及反应机理。考察了水相硝酸浓度、萃取剂浓度及温度对其萃取性能的影响。实验表明在不同稀释剂中TBDGA对Gd髥的萃取能力为:二甲苯四氯化碳甲苯氯仿,分配比在所研究酸度范围内都随硝酸浓度的增加而增大。在不同稀释剂中萃取机理是相同的,萃合物的组成为Gd(NO3)3·3TBDGA;萃取Gd(Ⅲ)离子的反应为放热反应,低温有利于萃取。萃合物的IR光谱表明羰基氧与Gd(Ⅲ)发生配位。     

在不同稀释剂中二（2—乙基己基）磷酸萃取Ni（Ⅱ）原热力学

研究了在不同稀释剂如苯，甲苯，正己烷，环己烷，四氧化碳，氯仿中萃取剂浓度，水相酸度以及温度对二（２－乙基己基）磷酸萃取Ｎｉ（Ⅱ）的平衡的影响，借助萃合物红外光谱，确定了萃合物组成和萃取反应机理。     

伯胺N1923在不同稀释剂中萃取盐酸平衡

用两相滴定法考察了伯胺Ｎ１９２３在煤油、氯仿、四氯化碳、甲苯、１，２－二氯乙烷和甲基异丁基酮等稀释剂中对盐酸的萃取，提出了处理萃取平衡的数学方法，观察到伯胺Ｎ１９２３与ＨＣｌ形成的铵盐萃合物在不同稀释剂中存在不同程度的聚合，并确定了聚合度，讨论了稀释剂极性铵盐聚合度的影响，认为铵盐的这种聚合实际上是它在有机溶剂中形成了反相胶团，其间的作用力可认为是“范德华力”。     

杯冠衍生物BEHBCalixC6对铯离子萃取性能的研究

本文以杯冠BEHBCalixC6为萃取剂,二氯甲烷为稀释剂,通过液液萃取,研究了BEHBCalixC6对苦味酸铯的萃取性能.研究表明,随着主、客体摩尔比的增加,萃取率增大.在摩尔比50:1时,萃取率可以达到77%以上.考察了测量参比溶液、预饱和两相稀释剂、稀释剂种类和溶液中Na+浓度等因素对萃取率的影响.     

稀释剂对二（2—乙基己基）磷酸萃取镧（Ⅲ）的影响

二（２－乙基己基）磷酸从硝酸介质中对Ｌａ（Ⅲ）的萃取对不同稀释剂其平衡常数为；正己烷＞环己烷＞四氯化碳＞甲苯＞氯仿＞甲异丁酮，萃取平衡常数与稀释剂的极性参数Ｓ间呈线性关系。     

磷酰胺类化合物萃取醋酸

以６种磷酰胺类化合物为络合剂，正辛醇和加氢煤油为稀释剂，研究了混合溶剂对醋酸稀溶液的萃取相平衡，讨论了磷酰胺类化合物的不同结构对萃取特性的影响．利用红外谱图和３１ＰＮＭＲ谱图分析了磷酰胺类化合物萃取醋酸的机理．     

不同稀释剂中HDEHP的界面性质研究

用滴体积法研究了HDEHP在不同稀释剂-0.05mol.dm^-^3(N2, Na2)SO4(pH=2.40)体系中的界面性质, 认为吸附于液-液界面的是单体HDEHP分子, 得到了各体系中HDEHP的Cmin, Tmax, Ai以及△Gad等界面吸附参数。HDEHP在不同稀释剂体系中的界面活性顺序为: 脂肪烃>芳香烃>氯仿>甲基异丁基酮, 这种变化主要是在体相中和界面上稀释剂与萃取剂、界面上的萃取剂及稀释剂与界面层水之间分子间相互作用的结果。同时讨论了HDEHP在不同稀释剂中的萃取动力学机理。     

Effect of binary extractants and modifier–diluents systems on equilbria of propionic acid extraction

Propionic acid is an important carboxylic acid widely used in chemical industries. The recovery from aqueous waste streams and fermentation broth is of research interest. Extraction of carboxylic acids by reactive extraction using extractant-diluent, mixed extractants in diluents and extractants in mixed diluents etc. are emerging areas of study. With this aim reactive extraction of propionic acid was carried out to study: (i) effect of binary extractants (tri-n-octylamine(TOA):tri-n-butylphosphate (TBP), TOA:Aliquat 336 and TBP:Aliquat 336), (ii) effect of modifier (1-decanol) in different diluents (kerosene, n-octane, n-heptane, petroleum ether, butyl acetate, MIBK, 2-octanol, dodecanol, hexane) and (iii) effect of phase volume. Improved extractions using binary extractants and binary diluents were observed. Since liquid–liquid extraction is dependent on effect of modifier concentration, effect of phase volume, presence of single or binary extractants and binary diluents, the study will be useful in the design of reactive extraction process for propionic acid recovery.     

Dependence of primary and secondary emulsion formation on the concentration of TBP,HNO3 and additives

Model studies on TBP—diluent—aqueous HNO₃ extraction systems were performed to establish the mechanism of emulsyfying during the reprocessing of spent reactor fuel with mixtures of TBP solutions. The systems of interest were emulsified under fixed conditions. The rate of separation of the primary emulsion as well as the turbidity of each phase were determined. The experiments were performed on mixtures of pure components of the extraction systems. Emulsion stability was investigated in terms of the influence of such factors as main products of TBP decay, the type of diluents, HNO₃ concentration and concentration of TBP in different diluents.     

Thermodynamics of solvent extraction of thorium by solutions of HHTA and mixtures of HHTA and TBP

The changes in free energy, enthalpy and entropy for the extraction of thorium by solutions of thenoyltrifluoroacetone (HTTA) and mixtures of solutions of HTTA and tri-n-butylphosphate (TBP), in three diluents, viz. cyclohexane, benzene and chloroform, were determined using the solvent extraction data obtained at different temperatures. From these data the thermodynamic parameters associated with the formation of Th(TTA)₄ · TBP in the respective organic diluents were evaluated. Trends in the enthalpy changes were attributed to different degrees of association of the diluents with themselves and with the solutes present in them.     

Some studies on synergic extraction of mixed ligand species of uranium(VI)

The extraction of U(VI) by mixtures of HTTA and TBP from aqueous thiocyanate medium has been studied. From the data obtained it was observed that the predominant uranium species extracted, causing synergic enhancement in the extraction of U(VI), is UO₂(SCN)TTA · 2TBP when benzene and cyclohexane are used as diluents, and that at a very low concentration of TBP the contribution of additional species, viz. UO₂(TTA)₂ · TBP becomes significant. With chloroform as diluent, however, both of these species are contributing to the synergic enhancement. The extraction of a quaternary uranium species, UO₂(SCN)TTA · 2TBP, involving the participation of the aqueous anion is thus established. Equilibrium constants for the various extraction equilibria involved are calculated.     

Studies on synergistic extraction of thorium by mixtures of HTTA and TBP

Synergistic extraction of Th(IV) from perchlorate medium by mixtures of HTTA and TBP was studied. These studies include the effect of the ionic strength, temperature and the diluents on the extraction. Ionic strength was found to influence the extraction of Th(TTA)₄ and Th(TTA)₄·TBP whereas the adduct formation in the organic phase was almost unaffected. Increase of temperature resulted in a decrease of the extraction of Th(IV). The stability of the adduct was found to decrease in the order, cyclohexane > benzene > chloroform.     

The effect of diluents on extraction of uranium(VI) with petroleum-sulfoxides (PSO)

The effect of diluents on the extraction of uranium(VI) with petroleum sulfoxides (PSO) was studied. The decreasing order of extraction ability of PSO is as follows: benzene, toluene, cyclohexane, heptane, kerosene, carbon tetrachloride and chloroform. The effect of temperature on the extraction equilibrium was also investigated and enthalpy of the extraction was obtained. The relationship between the extraction equilibrium constantsK _ex and the physical parameters of diluents can be derived.     

Kinetics of zinc(II) cloride extraction with tributyl phosphate

The equilibrium and rate of solvent extraction of zinc chloride complexes from HCl solutions into benzene solutions of tributyl phosphate (TBP) have been studied. The extracted species are discussed in the light of the results. The extraction was found to be first order with respect to both Zn(II) and TBP, and zero order for HCl. The rate-controlling steps are discussed and the rate constants for these reactions are calculated.     

磷酸三丁酯/正辛醇络合萃取对氯苯酚

以对氯苯酚稀溶液为研究对象,以正辛醇为稀释剂,研究了萃取剂种类及其浓度、水相平衡pH、对氯苯酚初始浓度等因素对萃取分配比的影响,并用NaOH对其负载溶质的有机相进行反萃.结果表明,络合萃取对处理高浓度对氯苯酚废水具有优势;磷酸三丁酯(TBP)的浓度和体系的pH是影响络合萃取的关键因素;采用NaOH对有机相进行反萃,当NaOH浓度为0.5mol/L时反萃率达到98.55%.红外光谱分析表明,TBP萃取对氯苯酚基于氢键作用机理.     

A reinterpretation of C5-BTBP extraction data, performed in various alcohols

The separation of trivalent actinides from trivalent lanthanides present in used nuclear fuel can be achieved by using solvent extraction and the BTBP class of ligands. This separation is relevant for the advanced reprocessing of the used fuel. The choice of diluents in such BTBP based systems has shown to affect the extraction as well as the separation. Long chained alcohols have previously been investigated as such diluents, showing that the americium extraction is higher into alcohols having shorter chains (hexanol, and heptanol) than in longer chained ones (nonanol and decanol). In this work it is shown that not only the distribution ratio, but also the contact time needed before reaching extraction equilibrium is shorter when using shorter chain length of the alcohol diluent. It is also shown that the rate of extraction can be correlated to the interfacial tension between the diluent and the aqueous phase. A low interfacial tension gives a fast extraction while an extraction system with higher interfacial tension needs a longer time of phase contact in order to reach extraction equilibrium.