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用2-乙基己基膦酸单(2-乙基己基)酯自硫酸溶液中萃取铟的机理研究 总被引:1,自引:0,他引:1
为了考察酸性磷类萃取剂化学结构上的差别对铟的萃取性能影响,本文研究了酸度对2-乙基己基膦酸单(2-乙基己基)酯[HEH(EH)P]萃取铟的影响,并与二(2-乙基己基)磷酸[HDEHP]进行比较;应用斜率法确定了萃取平衡反应;用饱和法制得了萃铟配合物,并测定了它们的红外光谱和核磁共振谱,在此基础上探讨了HEH(EH)P萃取铟的机理. 相似文献
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2-乙基己基膦酸单(2-乙基己基)酯[HEH(EHP),HL]是萃取分离稀土元素的有效萃取剂.作者及马恩新等研究了HEH(EHP)萃取低浓度稀土元素的平衡反应.Lenz等认为二(2-乙基己基)磷酸(HDEHP)萃取高浓度Nd(Ⅲ)和Sm(Ⅲ)时,ClO_4~-及NO_3~-参与萃取反应.定量研究HEH(EHP)从矿物酸溶液中萃取高浓度稀土元素(Ⅲ)的平衡规律及萃取反应具有实际意义,有关这方面的研究尚未见报道. 本文结合分离工艺,系统地研究了高浓度稀土元素在H~+(HNO_3,HCl)-H_2O-1.50FHEH(EHP)-煤油体系中的分配平衡,通过IR、NMR及平衡有机相中NO_3~-和Cl~-浓度的定量测定,提出了低酸度下不同稀土浓度的萃取反应. 相似文献
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研究了用2-乙基己基膦酸单-2-乙基己基酯(HEH/EHP,P507)和二(2-乙基己基)磷酸(HDEHP,P204)从硫酸介质中协同萃取Ce(Ⅳ)的机制.结果表明:在HEH/EHP的摩尔分散在0.6时,体系的协萃系数最大.Ce(Ⅳ)以Ce(SO4)0.5HL2A2的形式被萃人有机相,协萃反应为阳离子交换机制.同时还得到了HEH/EHP和HDEHP从硫酸介质中协同萃取Ce(Ⅳ)时,体系的平衡常数及热力学函数如△G,△H和△S等. 相似文献
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1 引 言萃取色谱法对于高纯稀土的分离具有其它方法无可比拟的独特优点 ,但该法仍存在负载量低、萃取剂利用率较低等不足。要克服这些不足 ,一是使用高选择的萃取剂作固定相 ,已证明 2 乙基己基膦酸单 2 乙基己基酯 (即P5 0 7)萃取剂是目前性能最好 ;二是提高柱效率 ,可通过改善色谱操作技术及色谱柱型式的设计或改善树脂物理结构来实现。而从树脂物理结构的角度提高柱效率的报道很少。本实验室原先对P5 0 7萃淋树脂的孔结构已做过一些研究 ,表明适宜的孔结构有利于萃取剂分布均匀 ,可提高萃取剂的利用率和分离性能 ,但树脂制备和分… 相似文献
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二(2,4,4—三甲基戊基)膦酸萃取稀土离子 总被引:9,自引:3,他引:9
2-乙基己基膦酸单2-乙基己基酯(HEH/EHP)是目前稀土湿法冶金工业中应用最广泛的萃取剂。但存在重稀土离子反萃取酸度高,某些中、重稀土离子对的分离系数小、选择性不高等缺点。所以研究优于HEH/EHP的新萃取体系已引起人们极大的关注。近年来发现,二(2,4,4-三甲基戊基)膦酸(HBTMPP,HL)有可能是萃取稀土元素的有效萃取剂。由于其分子中不含酯氧原子,使得它的pK。值比HEH/EHP高。因此,用HBTMPP萃取稀土及其它高价 相似文献
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HA( 2-乙基己基膦酸 2-乙基己基酯 )是一种性能优良的萃取剂,经皂化形成微乳液后,能大大提高萃取率 .许多学者对含有中长链醇等助表面活性剂的 HA碱皂微乳液的物理化学性质进行了深入的研究 [1- 4]. 本文报导了用 NaOH皂化不含任何助表面活性剂的 HA煤油溶液,当体系中的 NaOH与 HA数量比达到一定值时,会形成稳定的 W/O型微乳液 .不同的 nNaOH:nHA形成的微乳液的状态可能有所不同 .对这种不含助表面活性剂的微乳液的相行为、电导、溶水量等物理化学性质进行了初步研究 .1实验部分 ( 1) 仪器和试剂 DDS-11A型电导率仪,上… 相似文献
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氯代甲酸(2-乙基)己酯是一种化工中间体,主要用来制备过氧化二碳酸二(2-乙基)己酯(简称EHP),EHP是一种高活性聚合引发剂。由固体光气和2-乙基己醇为原料合成氯代甲酸(2-乙基)己酯的研究未见报道。本文以固体光气和2-乙基己醇为原料合成了氯代甲酸(2-乙基)己酯,研究了反应物加入顺序、反应时间、反应温度、催化剂种类及用量对氯代甲酸(2-乙基)己酯收率和纯度的影响,得到了优化的合成工艺,对产物结构进行了分析,进一步用其合成了常用的高活性聚合引发剂过氧化二碳酸二(2-乙基)己酯(EHP)。 相似文献
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Di-2-ethylhexyl hydrogen phosphate (HDEHP) and 2-ethylhexyl dihydrogen phosphate (H(2)MEHP) are compared as stationary phases in reversed-phase chromatography of selected lanthanides, strontium, yttrium, barium, manganese(II), iron(III), cobalt(II), nickel, gold(III), platinum(IV), palladium(II) and silver. Chromatograms were mainly developed with hydrochloric acid at various concentrations. In general H(2)MEHP was found to be less satisfactory than HDEHP. Development of chromatograms by dilute aqueous electrolytes on paper is slower and separations of chemically similar metals such as lanthanides is not encouraging. However, movement of lanthanides by EDTA at pH 3 in an aqueous sodium perchlorate medium occurs only on H(2)MEHP-treated paper. Good separations of iron(III) and cobalt(II) are possible on paper treated with either ester, and gold(III) and platinum(IV) are separated on HDEHP-impregnated paper. Column methods for the separation of carrier-free gold-199 and iron-59 from macro-amounts of neutron-irradiated platinum and cobalt, respectively, have been developed. 相似文献
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Yanliang Wang Yanling Li Wuping Liao Deqian Li 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(3):1651-1657
The extraction behavior of thorium(IV) by di-(2-ethylhexyl) 2-ethylhexyl phosphonate (DEHEHP, B) from nitric acid media has been investigated. The influence factors including the concentration of HNO3, salting-out reagents, temperature, the concentration of metal ions and DEHEHP have been examined systematically. A possible extraction mechanism is proposed and the extracted species as Th(NO3)4·2B (o) is confirmed by the slope analysis method. The extraction equilibrium constants (K ex) and thermodynamic parameters (ΔG, ΔH and ΔS) were calculated under the present experimental conditions. DEHEHP shows a high selectivity of thorium(IV) over rare earths(III). Stripping study indicates that thorium can be completely stripped by distilled water from the Th-loaded DEHEHP. Furthermore, a solvent extraction process including six extraction stages, six scrubbing stages, and six stripping stages was designed for the preparation of highly pure thorium from thorium concentrate with DEHEHP as extractant in laboratory scale, and finally thorium product can be obtained with a purity of 99.999 % and a yield of 98 %. 相似文献
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Dvořák B Bajerová P Eisner A Nykodýmová O Ventura K 《Journal of separation science》2011,34(14):1664-1668
The aim of this study was to develop and validate fast and easily applicable GC/MS assay for the quantification of the substance that increases cetane number in diesel fuel (2-ethylhexylnitrate, 2-EHN). These requirements were fulfilled best by a headspace GC-MS assay with negative chemical ionization with methane (HS-GC/MS). Chromatographic separation is achieved using a DB5-MS capillary column after the addition of known amount of internal standard (o-nitrotoluene). The limit of detection was 0.009% v/v for 2-EHN and the limit of quantification was 0.03% v/v. The HS-GC/MS method was applied for the quantification of cetane improver in spiked diesel fuel and real diesel fuel. The method is linear over the studied range (0.03-0.3%, v/v), with satisfactory intra- and inter-assay precision, and the relative standard deviations are lower than 10%. Good accuracy is achieved with bias <10% at all levels tested. 相似文献
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《Journal of membrane science》1999,156(2):187-196
The selective transport of plutonium across supported liquid membrane using an indigenously synthesized 2-ethylhexyl 2-ethylhexyl phosphonic acid (KSM-17, equivalent to PC 88A) dissolved in dodecane as carrier has been investigated in this work. Laminar type polypropylene hydrophobic microporous membranes were used as solid supports. Transport experiments were carried out to evaluate the effect of varied hydrodynamic and chemical compositions of the system, i.e., stirring speed, carrier concentration, anionic composition (e.g. SO2−4, NO−3, PO3−4, ClO−4, Cl−) and acidity of source phase (SP) solution. Transport rates of plutonium from SP solutions of different anionic composition followed the order: ClO−4>NO−3>Cl−>SO2−4>PO3−4. Selective permeability of plutonium was observed in the presence of several cationic impurities such as Al, B, Be, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Si, Zn, Ce, Dy, Eu, Gd and Sm. Using this technique, separation of plutonium from laboratory analytical waste was accomplished with an average flux 8.94×10−6 mol m−2 s−1 and with an enrichment factor greater than 2. The product solution obtained from this process was in oxalate medium with negligible contamination from other cationic and anionic impurities. From this solution, plutonium was precipitated as Pu-oxalate for further processing. Reusability of the membrane support was found to be satisfactory. 相似文献
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Solvent extraction of tin(IV) from hydrochloric acid media was carried out with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A) in toluene. Tin(IV) was quantitatively extracted with 2.5x10(-2) M PC-88A in toluene from 0.1-0.3 M HCl when equilibrated for 5 min. Tin(IV) from the organic phase was stripped with 4 M HCl and determined spectrophotometrically by both the morin and pyrocatechol violet method. The nature of the extracted species was determined from the log-log plots. Various other diluents such as xylene, hexane and cyclohexane also gave quantitative extraction of tin. The metal loading capacity of the reagent was found to be 0-15 ppm of tin(IV). The extraction of tin(IV) was carried out in the presence of various ions to ascertain the tolerance limit of individual ions. Tin(IV) was successfully separated from commonly associated metal ions such as antimony(III), bismuth(III), lead(II), thallium(I), copper(II), nickel(II), etc. The method was extended for determination of tin in real samples. 相似文献
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《Analytical letters》2012,45(21-22):1729-1750
Abstract To study the human metabolism of bis (2-ethylhexyl)-phthalate (DEHP) urine samples were analyzed from non-uremic psoriatic patients, uremic patients undergoing hemodialysis treatments and patients undergoing cardiac bypass surgery using High Performance Liquid Chromatography (HPLC). The urine of dialyzed non-uremic patients contained phthalic acid, mono (2-ethylhexyl) phthalate and bis (2-ethylhexyl) phthalate. Other compounds identified were p-hydroxy benzoic acid, m-hydroxy benzoic acid, o-hydroxy hippuric acid, o-hydroxy benzoic acid and benzoic acid, which may be either diet dependent normal urinary constituents or metabolites of bis (2-ethylhexyl) phthalate. The levels of phthalic acid and bis (2-ethylhexyl) phthalate found in the urine of patients who were on total body oxygenators containing a membrane during cardiac bypass surgery were comparable to levels obtained from non-uremic psoriatic patients. Significant levels of phthalic acid were detected in the urine of the uremic patients studied while mono (2-ethylhexyl) phthalate and bis (2-ethylhexyl)-phthalate were present only in small amounts or were completely absent. In general, the urinary phthalate content of uremic patients increased with urinary volume. 相似文献