碱土金属溶剂萃取分离的新进展

本文就碱土金属离子萃取分离的进展情况,按萃取剂的分类进行了综述。     

溶剂萃取法提取桂油

研究了溶剂萃取法提取桂油，应用正交试验及方差分析的方法分析了各种影响因素，确立了最佳工艺条件。     

超声波作用下溶剂萃取法分离镧铈元素

针对溶剂萃取法分离稀土元素的工艺中采用氨水为皂化剂造成排放的废水中氨氮含量超标,采用氢氧化钠为皂化剂使得排放废水中钠盐含量超标而造成环境污染的问题,研究了以未皂化的P204为萃取剂,超声波作用下镧铈元素萃取分离的方法。考察了料液酸度、超声波强度、超声波频率分别对镧铈分配比、分离系数及饱和萃取容量的影响。结果表明：当超声波强度为20 W/cm2、超声波频率为30 kHz、料液酸度为5时,镧铈元素的分配比、饱和萃取容量和元素间的分离系数达到最大,其中饱和萃取容量分别为35 g/L和19 g/L,镧铈间的分离系数最大为4.63。通过红外光谱检测可知溶剂萃取法分离镧铈元素时,由于超声波的作用使得萃取剂P204二聚体中的氢键部分断裂,因此有更多的单体P204能够与稀土离子发生萃取反应,所以超声波作用下镧铈的饱和萃取容量和分配比均大于无超声波作用。     

二氧化碳的分离提纯方法

综述ＣＯ２分离提纯的几种方法     

硝酸钾生产过程的母液处理—溶剂萃取法分离硝酸和盐酸

用磷酸三丁酯作萃取剂，煤油作稀释剂，可有效的从母液中萃取硝酸，达到硝酸和盐酸完全分离的目的，原料硝酸能完全回收，生成物直酸通过异戊醇萃取能得到纯净的盐酸作为副产品。     

溶剂萃取法分离油田卤水中的硼

以异辛醇为萃取剂,磺化煤油为稀释剂,从萃取剂体积分数、卤水pH值、相比、萃取时间、饱和萃取容量、反萃液pH值、反萃时间等方面考察了异辛醇对油田卤水中硼萃取的影响.结果表明:在卤水pH值为2、异辛醇体积分数为30％、相比(O/A)为1∶1、萃取时间为10 min时,通过4级萃取,硼的萃取率为95.3％;在相比为1∶l、反萃时间为10 min时用燕馏水3级反萃负载有机相,囊的反萃率达99％;整个过程穗的总回收率为94.3％.     

CO分离提纯技术研究进展

介绍了CO的主要生产工艺和分离提纯技术,重点介绍了CO络合分离原理及分离吸附剂的研究进展。我国每年排放大量富含CO的工业尾气,经分离提纯后可作为高浓度CO重要的来源,达到节能减排的效果。     

马奶溶菌酶的分离和提纯

蒙古马奶经过硫酸铵沉淀乳淀乳清蛋白脱盐，ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ－２５，ＳｅｐｈａｄｅｘＧ－１００，ＣＭ－Ｓｅｐｈａｄｅｘ－２５柱色层分离得到马奶溶菌酶。在ＳＤＳ－聚丙烯酰胺凝胶电泳法检验其纯度。     

溶剂萃取法净化磷酸中氟的研究

以三辛胺(TOA)为萃取剂净化磷酸中的氟离子,考察了稀释剂、萃取剂浓度、萃取时间、温度对萃取的影响,并研究了磷酸中杂质离子的存在对脱氟性能的影响。结果表明,在萃取剂TOA浓度0.5 mol/L(稀释剂为磺化煤油),萃取时间20 min,温度303 K,转速200 r/min,相体积比(O/A)=1∶1的条件下,脱氟率可达70%以上。磷酸中[Fe3+]=0.02～0.07 mol/L,[Mg2+]=0.06～0.08 mol/L范围内,对萃取脱氟是有利的,铝离子和钙离子的存在均不利于氟、磷的分离。     

溶剂萃取法提取亮氨酸和异亮氨酸

研究了用二（２－乙基己基）磷酸（Ｐ２０４）作萃取剂,从毛发水解生产胱氨酸的二次母液中提取亮氨酸和异亮氨酸的方法和条件。研究表明,在常温条件下,水相初始ｐＨ为４．０时,用３０％的Ｐ２０４（体积分数）正庚烷溶液,萃取相比为１,可萃取出水相中近７０％的亮氨酸和异亮氨酸。     

有机磷(膦)酸对碱土金属的萃取

Solvent extraction equiliria of four main alkaline earth metals (magnesium, calcium, strontium and barium) with di(2-ethylhexyl) phosphoric acid (DEHPA), 2-ethylhexyl phosphonic acid mono-(2-ethylhexyl) ester, di(2,4,4-tri-methylpentyl) phosphinic acid and IR spectra of the extracts have been studied. The selectivity order is dependent of the e/r value and hydration energy of the metal ions. The minor shift of the P→O in IR absorption of the alkaline earth metal extracts indicates that the interaction between the metal ions and P→O is much weaker for alkaline earth metals than for transitional metals. The distribution of the four alkaline earth elements between aqueous solutions and solutions of DEHPA and neutral organophosphorus compunds, tri-n-butyl phosphate (TBP) or tri-octyl phosphine oxide (TOPO) in kerosene have been determined at varying ratio of TBP or TOPO to DEHPA and the positive synergism is observed. The synergic effects is explained by using IR spectra of the loaded organic phase.     

CL—P507—HCl体系柱色层分离提纯高纯氧化钕的研究

用ＣＬ－Ｐ５０７－ＨＣｌ体系柱色层法对镨、钕元素的进行了研究。讨论了树脂粒度、淋洗剂浓度、负载量、盐效应、柱长径比等因素对分离的影响,确定了镨、钕分离的较适合的条件。将上述结果用于去除高纯氧化钕中的镨杂质,取得了令人满意的结果。     

Solvent extraction separation of vanadium(V) from multivalent metal chloride solutions using 2‐ethylhexyl phosphonic acid mono‐2‐ethylhexyl ester

The solvent extraction behaviour of vanadium(V) from hydrochloric acid solutions has been investigated using 2‐ethylhexyl phosphonic acid mono‐2‐ethylhexyl ester (EHEHPA ≡ HX) in kerosene as an extractant. For comparison, extraction studies have also been carried out with vanadium(IV). The results demonstrate that the extraction of vanadium(V) follows the cation exchange mechanism: where (HX)₂ refers to the dimeric form of EHEHPA. On the other hand, two dimeric molecules of EHEHPA were found to be involved in the extracted complex of vanadium(IV): The equilibrium constants of the above extracted complexes have been calculated and found to be K_ex,V(V) = 3.14 and K_ex,V(IV) = 0.32. The effect of the nature of the diluent on the extraction of vanadium(V) with EHEHPA has been studied and correlated with the dielectric constants. IR spectral studies of the extracted complex were used to further clarify the nature of the extracted complex. The separation and recovery possibilities of vanadium(V) from other associated metal ions, viz magnesium(II), aluminium(III), titanium(IV), chromium(III), manganese(II) and iron(III), which are present in the waste chloride liquors from the processing of titanium minerals, are also discussed. © 2002 Society of Chemical Industry     

Study on rosmarinic acid separation by synergic extraction

Separation of rosmarinic acid by synergic reactive extraction using a mixture of two extractants (one of aminic and one of basic type) dissolved in solvents with different polarities has been studied. By analysing the influences of the main factors (organic phase polarity, extractant concentration in the mixture) on the synergic effect, the most important synergic effect (C_S = 10.89) was found to correspond to the extractants mixture containing 5 g/l D2EHPA and 5 g/l Amberlite LA-2 dissolved in n-heptane. In this system the extraction constant reached the maximum value of 6.78 l²/mol².     

二-(2-乙基己基)磷酸合成工艺研究

研究了合成二－（2－乙基己基）磷酸的工艺优化条件，通过加入无水AlCl3，严格控制反应温度，控制三氯氧磷加入量过量3％等措施，合成的二－（2－乙基己基）磷酸萃取稀土元素性能优于标准萃取剂。     

Extraction and separation of rare earths from chloride medium with mixtures of 2‐ethylhexylphosphonic acid mono‐(2‐ethylhexyl) ester and sec‐nonylphenoxy acetic acid

BACKGROUND: 2‐ethylhexylphosphonic acid mono‐(2‐ethylhexyl) ester (HEHEHP, H₂A₂) has been applied extensively to the extraction of rare earths. However, there are some limitations to its further utilization and the synergistic extraction of rare earths with mixtures of HEHEHP and another extractant has attracted much attention. Organic carboxylic acids are also a type of extractant employed for the extraction of rare earths, e.g. naphthenic acid has been widely used to separate yttrium from rare earths. Compared with naphthenic acid, sec‐nonylphenoxy acetic acid (CA100, H₂B₂) has many advantages such as stable composition, low solubility, and strong acidity in the aqueous phase. In the present study, the extraction of rare earths with mixtures of HEHEHP and CA100 has been investigated. The separation of the rare earth elements is also studied. RESULTS: The synergistic enhancement coefficient decreases with increasing atomic number of the lanthanoid. A significant synergistic effect is found for the extraction of La³⁺ as the complex LaH₂ClA₂B₂ with mixtures of HEHEHP and CA100. The equilibrium constant and thermodynamic functions obtained from the experimental results are 10^?0.92 (K_AB), 13.23 kJ mol^?1 (ΔH), 5.25 kJ mol^?1 (ΔG), and 26.75 J mol^?1 K^?1 (ΔS), respectively. CONCLUSION: Graphical and numerical methods have been successfully employed to determine the stoichiometries for the extraction of La³⁺ with mixtures of HEHEHP and CA100. The mixtures have different extraction effects on different rare earths, which provides the possibility for the separation of yttrium from heavy rare earths at an appropriate ratio of HEHEHP and CA100. Copyright © 2009 Society of Chemical Industry     

Equilibrium characteristics for the extraction of cobalt and nickel into di(2-ethylhexyl) phosphoric acid

The liquid-liquid extraction of cobalt and nickel from aqueous sulphate solutions into di(2-ethylhexyl) phosphoric acid, DZEHPA, has been investigated at 25°C and 60°C. The system studied was made up as follows: the aqueous phase-cobalt and nickel dphates; the organic phase-20% D2EHPA, 75% Esso solvent DX3641 and 5% tri-butyl phosphate. Analogies to vapour-liquid equilibria were made to develop three methods to correlate the binary equilibrium data, namely: 1) a delta Y method, 2) a method based on the correlation of solvent free mole fractions in both phases and 3) a “pseudo activity” coefficient or pseudo gamma method, γ_AB. The methods were evaluated as to their suitability for the prediction of binary isotherms. The delta Y and pseudo gamma methods were found to give the best results.     

磷酸清洁工艺中溶剂萃取净化法的研究进展

综述了溶剂萃取净化法在湿法磷酸清洁生产中的应用和工艺,详细评述了国外各公司溶剂萃取法的工艺流程及我国在这方面的进展,并指出其发展趋势。     

Recovery of Plutonium(IV) from Aqueous Solutions Using Emulsion Liquid Membrane Containing 2‐Ethylhexyl Phosphonic Acid Mono‐2‐Ethylhexyl Ester as Ion Transporter

Abstract

An emulsion liquid membranes (ELMs) containing 2‐ethylhexyl phosphonic acid mono‐2‐ethylhexyl ester (H₂A₂) was tested for the extraction of plutonium(IV) from aqueous nitrate solutions of different compositions. Span 80 was used as the surface‐active agent and a mixture of 0.05 mol dm^?3 HNO₃+0.3 mol dm^?3 H₂C₂O₄ was used as the internal phase. Influence of some important experimental parameters such as exterior phase nitric acid concentration, ionic impurities in the exterior phase, concentration of H₂A₂ in ELM phase, and organic solvents on the ELM permeation process were systematically studied. The maximum efficiency of Pu extraction among group of experiments was 98% with permeability coefficient=0.508 min^?1, and the corresponding concentration factor of Pu in the receiving phase was ca. 10. The stability of the emulsions was tested in the presence of different organic solvents and at different concentrations of Span 80 in LM phase. The extractions of Pu by ELM from actual and simulated waste solutions as well as in presence of some added ionic impurities were investigated. Rate of Pu extraction by ELM was studied at different treatment ratios and under repeat extractions by the same emulsion. The repeat extraction experiments showed that a concentration factor of more than 80 for Pu could be achieved.