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2-乙基已基磷酸-2-乙基己基酯(P507)已广泛用于萃取分离稀土元素,用于萃取镓、铟、铊,在盐酸或硫酸介质中均具有较好萃取性质,易于反萃取。鉴于分析分离中萃取色谱法较萃取分离更为实用,我们进一步研究了萃取色谱分离镓、铟及其伴生元素的方 相似文献
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采用超临界CO2萃取法,使用正交试验设计方案,以提取率为指标,对萃取温度、萃取压力、分离压力和分离温度等影响因素进行考察。结果表明,超临界CO2萃取法萃取栀子花挥发油成分的最佳工艺条件为:萃取压力15mPa,萃取温度35℃,分离压力15mPa,分离温度25℃。该方法简便、可靠、选择性高,适于工业化生产。 相似文献
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稀土萃取分离过程自动控制研究现状及发展趋势 总被引:9,自引:2,他引:9
在简要描述稀土萃取分离生产过程的基础上,综述了目前国内外稀土萃取分离过程中稀土元素成分在线检测的方法、装置及其应用现状;稀土串级萃取分离生产过程的计算机流程模拟以及稀土萃取生产过程的自动控制方法、技术及其应用现状.指出了稀土元素组分含量的软测量方法,以综合生产指标为目标的稀土萃取分离生产过程优化控制方法以及由生产过程管理系统和过程控制系统两层结构组成的稀土萃取分离生产过程综合自动化系统已成为稀土萃取分离生产过程自动化未来发展的方向. 相似文献
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低浓度大体量复杂溶液中目标物的高效、精准、可控分离是当今化工分离科学领域的世界前沿课题。固相萃取技术目前用于低浓度复杂体系工业分离面临两方面挑战:一方面是高选择性精准捕获与温和绿色解吸难以兼具。另一方面是固相萃取技术缺少规模连续化分离的高效分离工艺设备。本文综述了为解决当前固相萃取技术存在的问题,实现低浓度复杂体系的高效精准和可控分离,新型环境响应固相萃取技术,磁场响应固相萃取技术以及电场、超声场辅助固相萃取技术取得的研究进展。最后,关于该应用领域固相萃取技术的研究发展方向进行了展望。本文对外场强化环境响应固相萃取技术的关键科学问题,包括环境响应问题、可控分离问题和过程放大问题进行了深入探讨,并对相关领域的发展提出了措施与建议。 相似文献
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乏燃料后处理中的三价锕系和镧系元素分离是“分离-嬗变”过程的主要环节,对于建立先进核燃料循环具有重要意义。然而,三价锕系和镧系元素结构与性质非常相似,实现二者的分离一直都是分离科学研究领域的难题。溶剂萃取法是三价锕系和镧系元素分离的基本方法之一,而运用含硫、氮等软配位原子的萃取剂则是实现分离的关键。在众多的萃取剂中,含氮杂环化合物因其优良的萃取分离能力,同时符合CHON原则而利于实现废物最小化,近年来引起了广泛的研究兴趣。本文综述了国内外研究报道的典型含氮杂环类三价锕系和镧系元素分离萃取剂,包括三联吡啶、TPTZ、BTP、BTBP以及以TPEN为代表的氮杂环取代胺类萃取剂,对其分离能力、稳定性等性能进行了比较,对萃取机理以及影响其萃取能力的因素等亦进行了说明,并对萃取剂的后续设计、改进提出了参考性建议。 相似文献
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本文通过计算机模拟计算,对恒定混合萃取比的三元稀土萃取分离工艺中有效分离系数的变化规律进行了研究,并在串级萃取理论的基础上提出了一种采用有效分离系数确定三元稀土萃取分离工艺参数的方法。 相似文献
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氯化亚锡活化-TOPO溶剂萃取分离铑铱及机理研究 总被引:1,自引:0,他引:1
在三正辛基氧化膦(TOPO)-乙酸乙酯体系中,应用氯化亚锡活化-溶剂萃取技术选择性分离Rh(Ⅲ)和Ir(Ⅳ),通过萃取铑实现铑铱的分离.考察了nSn/nIr、盐酸浓度对铱萃取率的影响.在相比为1 ∶ 1,nSn/nIr(nSn/nRh)=4,3 mol·L-1盐酸浓度的条件下,通过对含不同浓度铑、铱的料液进行萃取,铑的萃取率达到98%以上,铱的萃取率低于4%.在萃取过程中未能完全分离的铑铱通过HCl与KClO3的混合溶液以及硝酸的反萃实现分离.研究了贱金属的萃取行为,考察了贱金属及金对铑铱萃取分离的影响.将饱和萃取有机相减压蒸馏,通过红外光谱表征,探讨了萃取机理. 相似文献
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Liquid-liquid microbatch extraction system for rapid mutual separation of fission products 总被引:1,自引:0,他引:1
Takayuki Sasaki Koichi Takamiya Takayuki Ichihara Seiichi Shibata 《Analytica chimica acta》2003,484(2):139-144
The liquid-liquid microbatch extraction system (LMES) was developed for rapid separation of short-lived metal ions. The equipment is composed of three simple extraction cells for phase mixing, phase separation, and collection of a solvent. Metal separation can be completed in a single operation, lasting only a minute, from solvent extraction to preparation for gamma-ray spectrometry. As a demonstration of the rapid operation of the LMES, fission products were each separated into several categories after three stages of operation. The extractability in the LMES was comparable to that of traditional methods, and the developed method was feasible for rapid separation. 相似文献
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萃取分离是化学实验中常见的操作,依据多组分热力学中的分配定律,以拉格朗日乘子法推导并从理论上证明只有在均分萃取剂的情况下,才可使萃取效果最佳。且等均萃取的极限萃余率是与萃取剂物理性质、萃取剂用量等多方面因素有关。以实例讨论了不同因素,如萃取剂用量、萃取次数、分配系数对于萃取效果的影响。对于从事化学合成、分析、分离、化工等方向的科研工作者在指定萃取方案时,有一定的借鉴和指导意义,而且可以推广到稀释、固相分离等领域中。 相似文献
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A. M. Gaydukova V. A. Brodskiy V. V. Volkova V. A. Kolesnikov 《Russian Journal of Applied Chemistry》2017,90(8):1252-1257
Possibility of the electroflotation separation and extraction of cerium(II, IV), copper(II), and iron(II, III) from aqueous solutions is demonstrated. The optimal pH value and the concentration ratio of ions of the metals being separated, at which their electroflotation separation and extraction from aqueous solutions is the most efficient, was determined. It was shown that the electroflotation method is promising for selective separation and extraction of metal ions with various hydrate-formation pH values from aqueous solutions. 相似文献
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The extraction separation of rare earth elements is one of the most challenging separation processes in hydrometallurgy and advanced nuclear fuel cycles. The TALSPEAK process (trivalent actinide lanthanide separations by phosphorus-reagent extraction from aqueous komplexes) is a prime example of these separation processes. The objective of this paper is to explore the use of ionic liquids (ILs) for the TALSPEAK-like process, to further enhance its extraction efficiencies for lanthanides, and to investigate the potential of using this modified TALSPEAK process for separation of lanthanides among themselves. Eight imidazolium ILs ([C(n)mim][NTf(2)] and [C(n)mim][BETI], n = 4,6,8,10) and one pyrrolidinium IL ([C(4)mPy][NTf(2)]) were investigated as diluents using di(2-ethylhexyl)phosphoric acid (HDEHP) as an extractant for the separation of lanthanide ions from aqueous solutions of 50 mM glycolic acid or citric acid and 5 mM diethylenetriamine pentaacetic acid (DTPA). The extraction efficiencies were studied in comparison with diisopropylbenzene (DIPB), an organic solvent used as a diluent for the conventional TALSPEAK extraction system. Excellent extraction efficiencies and selectivities were found for a number of lanthanide ions using HDEHP as an extractant in these ILs. The effects of different alkyl chain lengths in the cations of ILs and of different anions on extraction efficiencies and selectivities of lanthanide ions are also presented in this paper. 相似文献
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A method is proposed for the extraction and mutual separation of quadrivalent titanium, zirconium and hafnium from hydrochloric acid using triphenylphosphine oxide dissolved in toluene as an extractant. The optimum conditions for the extraction and separation have been evaluated from critical study of acid concentration, extractant concentration, period of equilibration and effect of diluent. The effect of foreign ions on the extraction and determination is also discussed. The probable composition of the extracted species has been deduced from logD-logC plots. The method affords mutual separation of titanium, zirconium and hafnium and is applicable to the analysis of alloy samples. 相似文献
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On-line coupling of miniaturized solid-phase extraction methods and microcolumn separation techniques are reviewed. A conventional solid-phase micro-extraction device and fiber-in-tube solid-phase extraction was employed as the sample preparation method. In the fiber-in-tube technique, a novel fibrous polymeric material was introduced as the extraction medium for the microscale sample preparation step which could be directly coupled with microcolumn liquid-phase separation systems, such as microcolumn liquid chromatography, capillary electrophoresis, and capillary electrochromatography. The applications of these hyphenated systems, consisting of the sample preparation and separation processes, are also reviewed. 相似文献
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Elin Löfström-Engdahl Emma Aneheim Christian Ekberg Gunnar Skarnemark 《Journal of Radioanalytical and Nuclear Chemistry》2013,296(2):733-737
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. 相似文献