Extraction of Uranium(VI) by N-Octanoylpiperidine in Toluene

The extraction of uranium(VI) from nitric acid by N-octanoylpiperidine (OPPD) in toluene has been investigated at varying concentrations of nitric acid, extractant, salting-out agent LiNO₃ and at different temperatures. The mechanism of extraction is discussed in the light of the results obtained. The extracted species have also been investigated using FT-IR spectrometry. The related thermodynamic functions were calculated.     

Effect of diluents in U(VI) extraction with N,N'-dihexanoylpiperazine

A systematic investigation has been carried out on the extractive behavior of N,N'-dihexanoylpiperazine (DHPEZ) with respect to U(VI) in five diluents, from aqueous nitric acid media. The variation of U(VI) distribution ratio with the concentrations of aqueous nitric acid, extractant, salting-out agent and with temperature has been investigated and discussed. The increasing order of extractive ability of DHPEZ towards U(VI) is: chloroform, carbon tetrachloride, 1,4-dimethyl-benzene, toluene, benzene. The composition of the extracted species and extraction constants as well as the enthalpy changes are given.     

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。     

The effect of diluents on the extraction of rare earth elements by methyl-n-diheptylamine nitrate

The extraction of microquantities of rare earth elements (REE) by methyl-n-diheptylamine solution in mesitylene, p-xylene, toluene, benzene and nitrobenzene has been examined. The parameter measuring the solvation of extractant in aqueous and organic phases has been suggested to describe quantitatively the influence of diluents on the extraction of REE. It was found that in spite of the considerable influence of diluents under investigation on the extraction of REE by methyl-n-diheptylamine nitrate the stoichiometry of the extracting reactions of these elements has been the same for all diluents. It has been shown that in general the consideration of the interaction of the extractant and diluents only is not sufficient to explain the regularities of their influence on the efficiency of the separation of REE nitrates.     

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。     

Influence of the nature of organic diluents on the extraction of uranium(VI) by bis(2-ethylhexyl) sulfoxide from nitric acid solutions

The extraction of uranium(VI) from nitric acid solutions by bis(2-ethylhexyl) sulfoxide (BESO) has been examined using sixteen inert organic diluents in order to establish the correlation between its distribution coefficient and some physico-chemical properties of the diluents. The extracted solvated species is shown to be UO₂(NO₃)₂·2BESO, irrespective of their nature. The extraction rate is lower in halogen substituted hydrocarbons as compared to the other diluents used. Among benzene derivatives, extraction is found to decrease with number of substituted methyl groups. Extraction efficiency decreases as the organic solvent is varied in the order: benzene>nitromethane>toluene> >nitrobenzene>cyclohexane>p-xylene>monochlorobenzene>dodecane>o-dichlorobenzene> >hexane>decalin>1,2-dichloroethane>1,1,1-trichloroethane>carbon tetrachloride> >tetrachloroethane>chloroform. Among the properties showing good correlations with distribution coefficient are Hansen's three-dimensional solubility parameters and Dimroth's empirical solvent polarity parameters [E _T(30) ]. Polarizability indices are most satisfactorily applicable to a wide variety of solvents.     

The influence of diluent on the extraction behavior of uranium with N-octanoylpyrrolidine

Extraction of uranium(VI) from nitric acid solutions with N-octanoylpyrrolidine(OPOD) in a series of diluents has been studied. The dependence of the extractiondistribution ratios on the concentrations of aqueous nitric acid, extractant,salting-out agent and the temperature was investigated. The experimental resultsshowed that the extracting capacity of OPOD in different diluents increasesin the order: chloroform, carbon tetrachloride, 1,2-dichloroethane, n-dodecane,n-octane, cyclohexane, toluene and benzene. This can not be explained onlyon the theory of polarity of the diluents. The interaction between extractantand the extracted complex and diluent is discussed.     

不同稀释剂中TBP萃取醋酸的研究

研究了不同稀释剂中ＴＢＰ对醋酸的萃取，其萃取能力在不同稀释剂中按甲苯〉苯〉环己烷〉煤油〉四氯化碳〉氯仿〉甲基异丁基酮的顺序变化，求出了萃取反应的焓变，建立了萃取平衡常数与稀释剂物理参数间的经验方程，并用红外光谱对萃取机理进行了研究。     

N,N-二烷基酰胺萃取硝酸的性能

酰胺萃取剂的羰基氧具有很强的碱性,易萃取酸.考虑到酰胺萃取酸后对其萃取金属离子的性能有影响,研究酰胺对硝酸的萃取是必要的.     

Liquid anion-exchange separation of vanadium from malonate media

Summary Vanadium(IV) and (V) can be quantitatively extracted with 0.2 mol/l Amberlite LA-2 in xylene at pH 3.0 from 0.02 mol/l malonic acid, stripped with 0.5 mol/l hydrochloric acid, and determined spectrophotometrically. Five other liquid anion exchangers (Amberlite LA-1, Primene JM-T, Aliquat 336S, TOA and TIOA) were examined as possible extractants. The extraction of vanadium(IV) was found to be quantitative only with Amberlite LA-2, while that of vanadium(V) was quantitative with Amberlite LA-1 and LA-2, Primene JM-T and Aliquat 336S. Eight common solvents were tested as diluents; of these hexane, cyclohexane, benzene, and xylene were found to be satisfactory. Vanadium was separated from elements that do not form anionic complexes with malonic acid by selective extraction, from those that form weak complexes by washing the organic extract with water, and from metals that form strong malonato complexes by selective stripping with hydrochloric, nitric, or sulphuric acid. The method has been applied to the determination of vanadium in steel, coal fly ash and fuel oil. The precision of measurement is within ±5% and the detection limit of the method for vanadium is 0.5 mg/kg.     

Dioctyl butyramide and dioctyl isobutyramide as extractants for uranium(VI) and plutonium(IV)

Two isomeric monoamides, dioctyl butyramide (DOBA) and dioctyl isobutyramide (DOIBA) were synthesized for extracting uranium(VI) and plutonium(IV) from aqueous nitric acid medium into various diluents such asn-dodecane, tertiary butyl benzene and xylene. DOBA extracted uranium(VI) and plutonium(IV) efficiently whereas DOIBA extracted uranium(VI) with negligible extraction for plutonium(IV). Both these cations were extracted as their disolvates. The thermodynamic parameters involved in the extraction determined by the temperature variation method indicated the reactions in all cases to be enthalpy favoured and entropy disfavoured. Possibility of separating micrograms of plutonium(IV) from macroquantities of uranium(VI) using the mixture of these amides was explored.     

Extraction of Nitric Acid and Np(IV) by some aliphatic ketones and alcohols

The extraction behaviour of HNO₃ and Np(IV) from aqueous nitrate solutions with some aliphatic alcohols and ketones using hexane, carbon tetrachloride, benzene and chloroform as diluents was studied. The acid concentration in the aqueous phase varied from 0.25 to 10 M and that of the extractant in the organic phase varied from 0.5 M to the undiluted fraction. In the alcohol systems, solutions of the same alcohol in the diluents CCl₄ and CHCl₃ showed similar capacity for acid extraction, and also in the same diluents, solutions of diisopropyl and diisobutyl alcohol showed similar capacity for extraction. Extraction of Np(IV) with the different ketones and alcohols used follow the same pattern as HNO₃.     

Synergistic solvent extraction studies of uranium(VI) using a combination of naphthenic acid and various neutral donors into benzene

The equilibrium extraction behavior of uranium(VI) using a benzene solution containing naphthenic acid either alone or combined with one of the adductants viz., diphenyl sulphoxide, dinonyl sulphoxide, tri-n-butyl phosphate, triphenyl phosphine oxide, tri-n-octyl phosphine oxide, triphenyl arsine oxide, 2,9 dimethyl 1,10-phenanthroline, 1,10-phenanthroline, 4,7-diphenyl 1,10-phenanthroline, 2,2′-bipyridyl and 2,2′-biquinoline is described. The enhancement in the extraction by addition of such neutral adducts is explained in terms of adduct formation of the metal chelates in the organic phase. The composition of the extracted species is obtained from slope analysis and pH_0,5 values are also obtained. The effect of various parameters such as equilibrium pH, extractant concentration, various diluents on the extraction of U(VI) with 2% naphthenic acid has been carried out. Stripping or back extraction with various mineral acids was also studied.     

The use of14C,59Fe and65Ni radionuclides for the study of solvent effects on the extraction equilibria with n-caprylic acid

The distribution of n-caprylic acid between an aqueous sodium sulphate solution and several organic diluents of various properties has been investigated, using¹⁴C-labelled n-caprylic acid. The distribution coefficients of the monomeric capyrlic acid and its dimerization constants in the organic phase were determined. The extraction of Fe(III) and Ni(II) with n-caprylic acid solutions in various diluents was studied using the AKUFVE solvent extraction equipment. The composition of the extracted compound of Fe(III) has been determined and the extraction constants for all the studied systems have been calculated. For the extraction of Ni(II) the constants of the extraction of nickel caprylate monomers and its dimerization constants in the organic phase have been calculated.     

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.     

二-(2-乙基己基)磷酸在不同稀释剂中对钙、钴(Ⅱ)的萃取

本文测定了25±1℃时二-(2-乙基己基)磷酸在不同稀释剂中从硫酸盐水溶液里对钙、钴(Ⅱ)的萃取,计算得到了萃取络合物中结合的自由萃取剂分子数和萃取平衡的表观常数,并讨论了溶剂对萃取的影响。     

Dicyclohexano 18 crown 6 in butanol-octanol mixture: A promising extractant of Sr(II) from nitric acid medium

The extraction of strontium from nitric acid medium was investigated employing DCH18C6 in aliphatic alcohols as the diluents. 80% Butanol-20% octanol mixture was found to give higher D(Sr) values as compared to other alcohols investigated. A linear correlation between the organic phase water content and D(Sr) was observed, based on which the extraction mechanism was postulated. Effect of anion, cation, extractant concentration, nitric acid concentration and temperature on D(Sr) was also studied. Conditions for recovery (>90%) were arrived at and selectivity with respect to other interfering fission products was observed with most of the metal ions studied.     

Solvent extraction of uranyl by N,N,N′,N′-tetraoctylsuccinylamide from nitric acid solution

Synthesis and characterization of N,N,N′,N′-tetraoctylsuccinylamide (TOSA) was carried out and used for extraction of U(VI) from nitric acid solutions. The effect of different factors affecting the extraction distribution ratio (TOSA concentration, concentrations of nitric acid, salting-out agent LiNO₃ concentration, equilibration time, temperature and effect of diluents) have been investigated. The results obtained indicated that TOSA have a great capability to extract uranyl with kerosene-1,3,5-trimethylbenzene than other diluents, it have a high extraction distribution ratios when the concentration of TOSA is lower and not found the third matter. It was found that the main extracted species is UO₂(NO₃)₂·TOSA. The apparent equilibrium constant of extraction determined is (2.32 ± 0.31) L³/mol³ at (298 ± 1) K. The enthalpy of extraction is ?35.20 ± 0.352 kJ/mol.     

1-苯基-3-甲基-4-苯甲酰基吡唑啉酮-5与胺类缔合研究

1-苯基-3-甲基-4-苯甲酸基毗哇琳酮一5（HPMBP）是一类酸性鳌合革取剂,已广泛用于多种元素分离、分析研究［'j．它不仅在单独使用时能很好地革取金属,而且在与有机胺类共同使用时对稀土元素、过渡金属元素有明显的快同革取性能L'·'］．因此研究HPMBP与胺类的相互作用对于分析产生协同作用的原因,改善革取性能是很有必要的．1实验部分1．1试剂HPMBP,化学纯（北京试剂厂）;三千胺（TOA）,FLUKA进口分装试剂,纯度大于99％;伯胺N1923,工业级（上海有机化学研究所化学实验厂）,经减压（267～533Pa）蒸馏,收集413～459K馏…     

Extraction of bismuth(III) with 2-bromoalkanoic acid in nondonating solvent from highly acidic aqueous solution.

The extraction behaviors of bismuth(III) with carboxylic acid (HL), which have not yet been clearly elucidated, because of the precipitation of hydroxide, were studied using the 2-bromoalkanoic acid in benzene and in hexane systems under aqueous conditions of high acidity at I = 1.0 M ((H,Li)NO3). The extraction equilibria were analyzed based on the-initial concentration of nitric acid and the concentration of bismuth(III) extracted in the organic phase. The extracted species and the logarithmic values of the extraction constant (log Kex) were found to be a single species of BiL3(HL)3 for the systems of 2-bromooctanoic acid/benzene (log Kex = -1.66) and 2-bromohexadecanoic acid/benzene (-1.58), and to be two species of BiL3(HL)4 (-1.01) and Bi3L9HL (-1.62) for the system of 2-bromooctanoic acid/hexane, where the monomer was dominant at a higher reagent concentration.