Selective recovery of lithium from simulated brine using different organic synergist

The organic synergists, including Octanol, ethyl acetate(EA), butyl acetate(BA), methyl isobutyl ketone(MIBK),diisobutyl ketone(DIBK), N,N-bis(2-ethylhexyl) acetamide(N523) and 8-hydroxylquiolate, were added to the TBP–FeCl_3 extraction system to extract lithium from brine. The effects of concentration of organic synergist and total organic extractant, molar ratio of Fe/Li, phase ratio, counter-current extraction and the acidity of stripping agent on lithium extraction were investigated to optimize the extraction conditions. Under the optimize conditions, the results of counter-current extraction showed the mixed extraction system was the preponderance on the lithium extraction. Especially the separation of lithium in organic phase and aqueous phase and the separation mass ratio of Mg/Li increased greatly. An extraction mechanism was proposed based on the analysis of FT-IR spectra and Raman spectra.     

Extraction Equilibria of Trimellitic and [ 1,1′-Biphenyl]-2,2′-dicarboxylic Acid with 1-Octanol, 50%TBP,and 10%TRPO in Kerosene

To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1′-biphenyl]-2,2′-dicarboxylic acid, were selected as the solutes, and the extraction equilibrium of the acids were studied with 1-octanol, 50% tributyl phosphate （TBP） in kerosene, and 10% trialkylphosphine oxide （TRPO） in kerosene. The results showed that the degree of extraction of [1,1′-biphenyl]-2,2′-dicarboxylic acid was larger than that of trimellitic acid for all of the solvent, and the extraction capacity with TRPO is more effective than the one with TBP. The extraction behavior of aromatic polyacid is different from that of carboxylic acid, and the reactive extraction function of aromatic acids with TBP and TRPO is not as effective as that of carboxylic acid. 1-octanol could be used to remove [1,1′-biphenyl]-2,2′-dicarboxylic acid from the mixture of trimellitic acid and [1,1′-biphenyl]-2,2′-dicarboxylic acid. Because the weak hydrogen bond association exists between -OH in 1-octanol and -COOH in aromatic acid, the extractive selectivity of [ 1, 1′-biphenyl]-2,2′-dicarboxylic to trimellitic acid depends on the stoichiometric ratio.     

Extraction of rubidium by t-BAMBP in cyclohexane

4-Tert-butyl-2-(α-methylbenzyl) phenol (t-BAMBP) was used in cyclohexane in the extraction of rubidium from brine sources containing lithium. The effect of t-BAMBP concentration and aqueous phase pH on the rubidium and lithium extraction equilibrium was studied. t-BAMBP/cyclohexane was efficient and selective for rubidium extraction with optimal operating conditions being pH of 13.0 and initial t-BAMBP concentration of 1.0 mol·L?1. The stoichiometry of the complex of t-BAMBP with rubidium is 4:1. The apparent extraction equilibrium constant of rubidium was calculated by fitting the experimental data.     

Direct extraction of Mo(Ⅵ) from sulfate solution by synergistic extractants in the rotation column

Direct extraction of molybdenum from sulfate solution with synergistic extractants(mixture of D_2EHPA and TBP)was studied in the rotation column. The influence of extractant concentration and initial pH of aqueous phase was studied in the bench scale experiments. The outcomes demonstrated that the synergistic solvent extraction enhances the constancy of the extracted complexes for transfer into the organic phase. In the continuous experiments, the effect of different operating parameters such as speed of agitation, inlet solvent flow rate and inlet aqueous flow rate on the holdup, mean drop size, drop size distribution, slip and characteristic velocities and extraction percentage were examined. Modified correlations were proposed for prediction of hydrodynamic parameters with consideration of reaction extraction condition in the rotation column. Furthermore, these correlations were compared with the experimental data. According to the results, the direct extraction of Mo(Ⅵ) from aqueous solution and sulfuric media with extraction efficiency of 90.4% was obtained at higher rotor speed(240 r·min~(–1) rpm) in this column.     

Concentration of linoleic acid from cottonseed oil by starch complexation

The extraction of linoleic acid from fatty acids(FA) of the cottonseed oil using starch–FA complexes was developed for the first time. We showed that starch can form inclusion complexes of different strengths with FA and that the different strengths stem from the differences in chain length, degree of unsaturation, and position of double bonds of FA. The optimal separation conditions were determined as follows: The inclusion temperature is 69 °C, the inclusion time is 30 min, the starch/FA mass ratio is 10:1, and the ratio of the volume of methanol–water solution and the mass of FA is 18:1. Compared to urea inclusion complexation, starch complexation has milder reaction temperature and shorter reaction time. Under these conditions, linoleic acid can be concentrated from 38.9% to 70.04% by one-off extraction. Moreover, the experimental results demonstrate the almost perfect reusability of starch. These results show that starch complexation is a promising method that can be used to obtain highly concentrated linoleic acid from cottonseed oil.     

Extraction of Lithium from Brine Containing High Concentration of Magnesium by Tri-n-Butyl Phosphate Dissolved in Kerosene

Tri-n-butyl phosphate(TBP)dissolved in kerosene was chosen as extractant for lithium from a modelbrine having high magnesium-to-lithium ratio and ferric chloride was added to the system.The influences of con-tact time,concentration of the extractant,concentrations of some salts(Mg~(2 ), Na~ ,K~ )in the solution,acid-ity of hydrochloric acid and extraction temperature on the exttaction of lithium with TBP-kerosene system werestudied.The suitable extraction conditions were found to be:contact time not any less than 20min;at 20-25C;[Fe~( 3)]/[Li~( )]about 1.5-2.0;TBP concentration 50%-70%;[MgCl_2]exceeding 3 mol·L~(-1);pH about 2;while most sodium and potassium salts in the aqueous phase should be removed before the extraction.     

三辛胺萃取丁二酸、苹果酸、马来酸、富马酸特性的研究

Extraction equilibrium features of succinic acid, malic acid, maleic acid and fumaric acid were investigated systematically with trioctylamine (TOA) in chloroform, 4-methyl-2-pentanone (MIBK) and 1-octanol. Fourier transform-infrared (FTIR) spectroscopic analysis of organic samples loaded with the acid shows that amine forms 1:1 complex of ion-pair association with succinic acid, malic acid and maleic acid, and 1:1, 2:1 complex of ion-pair association with fumaric acid. It is proposed that the complex forms depend on the second dissociation constant of the dibasic acid, pKa2 Results of equilibrium experiments show that diluents affect extraction behavior, and depend on the solute concentration. Protic diluents, chloroform and 1-octanol, are more effective than the others when the equilibrium solute concentration is lower than 1:1 stoichiometry of TOA to acid, otherwise the extraction ability shows that MIBK>l-octanol>chloroform for malic and maleic acids, and l-octanol>MIBK>chloroform for succinic acid.     

Self-assembled bright luminescent hierarchical materials from a tripodal benzoate antenna and heptadentate Eu(III) and Tb(III) cyclen complexes

The europium heptadentate coordinatively unsaturated (Eu(III)) and the terbium (Tb(III)) 1,4,7,10-tetraazacyclododecane (cyclen) complexes 1 and 2 were used in conjunction with ligand 3 (1,3,5-benzene-trisethynylbenzoate) to form the supramolecular self-assembly structures 4 and 5;this being investigated in both the solid and the solution state. The resulting self-assemblies gave rise to metal centered emission (both in the solid and solution) upon excitation of 3, confirming its role as a sensitizing antenna. Drop-cased examples of ligand 3, and the solid forms of 4 and 5, formed from both organic and mixture of organic-aqueous solutions, were analyzed using Scanning Electron Microscopy, which showed significant changes in morphology;the ligand giving rise to one dimensional structures, while both 4 and 5 formed amorphous materials that were highly dense solid networks containing nanoporous features. The surface area (216 and 119 m2·g^-1 for 4 and 5 respectively) and the ability of these porous materials to capture and store gases such as N2 investigated at 77 K. The self-assembly formation was also investigated in diluted solution by monitoring the various photophysical properties of 3–5. This demonstrated that the most stable structures were that consisting of a single antennae 3 and three complexes of 1 or 2 (e.g., 4 and 5) in solution. By monitoring the excited state lifetimes of the Eu(III) and Tb(III) ions in H2O and D2O respectively, we showed that their hydration states (the q-value) changed from -2 to 0, upon formation of the assemblies, indicating that the three benzoates of 3 coordinated directly to the each of the three lanthanide centers. Finally we demonstrate that this hierarchically porous materials can be used for the sensing of organic solvents as the emission is highly depended on the solvent environment;the lanthanide emission being quenched in the presence of acetonitrile and THF, but greatly enhanced in the presence of methanol.     

AOT反胶束萃取胰蛋白酶的STM及主要影响因素

In this article, the influence factors of trypsin extracted from crude pancreatin was investigated, and scanning tunneling microscope(STM) was used to observe the image of trypsin in butane-diacid-2-ethyl-hexyl-ester-sulfonic sodium (AOT)/iso-octane reversed micelles. The STM image showed that trypsins bounded in reversed micelles was rigid, which weakened its conjugative effect and caused maximum ultraviolet absorption and fluorescence emissive absorption moving toward blue waves. AOT concentration, pH and cations were the main influence factors of extraction. Specifically, extraction percentage of trypsin decreased with the increase of AOT concentration from 0.01 to 0.1mol·L-1. When pH value is from 5.30 to 10.0, i.e. less than pI of trypsin, the extraction percentage is raised with the different increase of pI-pH, but when the pH value is less than 5.20, the extraction percentage is decreased with the acidity added. Besides, the extraction efficiency is negative, related with the concentrations of Ca2 , Na ,K which were in the range of 0.2-1.0mol· L-1, and influence of concentration of Ca2 is greater than that of Na , and K which has the minimum impact with the same concentration. Finally, optimum conditions to extract trypsin were: AOT reversed micelles 0.05mol·L-1, trypsin concentration in crude pancreatin solution 3mg·ml-1, pH 5.2- 5.3, ratio (by volume) of extraction phase to strip-extraction phase 1:1, and time of 5min. The corresponding percentage of extraction was 22.7% and specific activity was 78.9 N-benzoyl-L-arginine ethyl ester (BAEE) U·mg-1 protein, three times than that in crude pancreatin. There was no lipase and amylopsin activity was decreased to 1/5 of crude pancreatin. Partly purifying solution was treated by condition mentioned above with 0.05mol·L-1 ceryl-trimethyl-ammonium bromide (CTAB), total extraction percentage of trypsin was 74.18% and specific activity was 3148.3 BAEE U·mg-1, i.e. 48.16 times purer than that in crude pancreatin. Through sodium dodecyl sulfate-polyacryl amide gel electrophoresis (SDS-PAGE) and image analysis of extracted product, there were only three bands in the trypsin, while seven in crude pancreatin, and electrophoresis location of main bend was almost identical with the standard enzyme.     

双进料模拟移动床分离α-生育酚(英文)

A two-feed simulated moving bed(SMB) was proposed to utilize the stationary phase more effectively.Zone I is disconnected with zone II and zone III is disconnected with zone IV.Two feeds are added to zones I and III,while two desorbents are added to zones II and IV separately.The investigation on the movement of concentra-tion bands indicated that the tail of the strong retained solute and the front of the weak retained solute were eluted from zones I and III orderly,so the streams from zones I and III could be cut into different fractions to give the products with high purity.The two-feed SMB was used to separate α-tocopherol from its homologue mixture suc-cessfully,and could double the productivity if both feeds were identical to the feed in the conventional four-zone SMB.The solvent consumption could be reduced by reusing the middle fraction without solutes.     

磷酸三丁酯/甲基异丁基酮萃取锂的特性

为从含有Li和Mg的水溶液中选择性地萃取Li,在FeCl3存在的条件下,以磷酸三丁酯(TBP)为萃取剂,以煤油为稀释剂,在萃取平衡时出现第3相的情况下研究了有机相中Li和Fe的浓度,结果表明萃合物主要集中在中间有机相.针对萃取过程中的分相问题,以TBP为萃取剂,比较了甲基异丁基酮(MIBK)、乙酸乙酯和煤油作为稀释剂对...     

离子液体体系用于盐湖卤水提取锂

3种咪唑类离子液体:1-丁基-3-甲基咪唑六氟磷酸盐([C₄mim][PF₆])、1-己基-3-甲基咪唑六氟磷酸盐([C₆mim][PF₆])、1-辛基-3-甲基咪唑六氟磷酸盐([C₈mim][PF₆])被作为绿色溶剂用于盐湖卤水分离镁锂, 建立了以离子液体(ILs)、磷酸三丁酯(TBP)分别为萃取介质和萃取剂的盐湖卤水锂萃取体系, 并与使用传统有机溶剂磺化煤油和氯仿的萃取效果进行了对比。研究发现, 该离子液体体系较使用传统挥发性有机溶剂的萃取体系有更高的萃取率。锂的萃取率随离子液体中烷基碳原子数的减小而增加。详细考察了溶液pH、离子液体浓度、相比对萃取效率的影响, 获得了离子液体体系萃取的最优条件。在最佳萃取条件下, 3种离子液体体系对锂的单级萃取效率均高于80%, 分离系数最高达到100以上。机理研究表明:离子液体体系是以阳离子交换实现对锂的萃取, Li⁺与TBP形成[Li·2TBP]⁺络合物进入有机相。     

磷酸三丁酯萃取体系从盐湖卤水提取锂

选取磷酸三丁酯（TBP）为萃取剂,磺化煤油为稀释剂,氯化铁（FeCl₃•6H₂O）为共萃取剂从盐湖提钾老卤萃取锂。考察了不同因素对萃取率的影响,结果发现,相比（O/A）对萃取率的影响最大,铁锂物质的量比次之,TBP含量（体积分数）影响最小;由单因素实验及正交实验的研究分析得出萃取锂的最优工艺条件：φ（TBP）=80%、相比（O/A）为2.0、n(Fe)∶n(Li)=1.5、c(H⁺)=0.05 mol/L、振荡时间为5 min;该工艺萃取效率高,单级萃取率可达91.4%,且具有良好的稳定性和重现性,可为工业扩大化生产提供可靠的参考依据。     

Optical Spectroscopic Investigation of Hexavalent Actinide Ions in n-Dodecane Solutions of Tri-butyl Phosphate

ABSTRACT

The extraction of hexavalent actinides An(VI) by tri-butyl phosphate (TBP) was investigated by electronic absorption and vibrational spectroscopies. Through a series of spectral subtractions, vibrational spectra associated with TBP, TBP–HNO₃ adducts, and An(VI)–TBP complexes could be isolated. Investigation of U(VI) extracts indicated spectral features consistent with the formation of the expected [UO₂(NO₃)₂(TBP)₂] complex, but spectral features of other species were clearly evident. Likewise, multiple species were evident in the electronic absorption and vibrational spectra of TBP phases generated by extraction of Pu(VI). Although definitive characterization of the additional species formed could not be achieved in this work, it is hypothesized that they contain 3:1 TBP-to-An(VI) stoichiometry.     

尖晶石型锂锰氧化物离子筛的制备方法及构效性能分析

尖晶石型锂锰氧化物离子筛作为一种溶液提锂的吸附材料, 具有广阔的应用前景, 而在实际研究与推广应用进程中, 也存在着一些问题。文章结合已有的研究, 详细介绍了目前研究最多的三种锂锰氧化物离子筛前体(LiMn₂O₄、Li₄Mn₅O₁₂ 和 Li_1.6Mn_1.6O₄)和对应锰氧化物离子筛(λ-MnO₂、MnO₂·0.31H₂O和MnO₂·0.5H₂O)制备方法的比较;重点分析了三种前体和离子筛的晶体结构特征以及离子筛吸附性能的本质区别;对粉状离子筛的成型(造粒和成膜)作了详细阐述并与粉状离子筛的性能进行了比较;最后总结了目前锂锰氧化物离子筛实际吸附量与理论吸附量的差异和选择性以及离子筛溶损等现存的问题。随着离子筛成型技术的改善和掺杂新型离子筛的开发, 有望制备工业化应用的海水提锂吸附剂。     

离子液体体系卤水提锂的洗涤工艺研究

溶剂萃取法是盐湖提锂的重要工艺方法。采用磷酸三丁酯（TBP）/1-丁基-3-甲基咪唑双三氟甲基磺酰亚胺盐（[C₄mim][NTf₂]）离子液体体系对高镁锂比盐湖卤水中的锂进行萃取分离提取实验,对负载有机相的洗涤和反萃过程进行了研究。萃取实验：在TBP与[C₄mim][NTf₂]体积比为9∶1、相比（有机相与水相的体积比）为2∶1条件下,锂离子与其他离子的分离系数分别为β（锂/钠）=94.70、β（锂/钾）=148.85、β（锂/镁）=131.81。洗涤实验：系统考察了洗涤剂种类及浓度、相比、洗涤次数等因素对杂质离子洗脱率的影响,结果发现氯化锂和盐酸的混合溶液是从负载有机相中洗涤除去杂质离子的有效洗涤剂。洗涤过程适宜条件：洗涤剂中氯化锂浓度为4 mol/L、盐酸浓度为0.5 mol/L,相比为5∶1,洗涤次数为2次。反萃实验：用稀盐酸（1.0 mol/L）对负载有机相进行反萃取,在相比为1∶1条件下,单级反萃率达到97.81%。研究表明,离子液体体系作为一种新型萃取体系,在高镁锂比盐湖卤水中提取锂具有较好的应用前景。     

Extraction properties of phthalic acid and aromatic polycarboxylic acids using various solvents

BACKGROUND: To explore the extraction properties of aromatic acids produced in the oxidation of coal, the extraction equilibrium of phthalic acid (as a typical product) was studied using three solvents, 1‐octanol, 50% tributylphosphate (TBP)/kerosene, and 10% trialkylphosphine oxide (TRPO)/kerosene, and the feasibility of separating phthalic, [1,1′‐biphenyl]‐2,2′‐dicarboxylic and trimellitic acids is discussed. RESULTS: Phthalic acid extraction followed the sequence: 10% TRPO > 50% TBP > 1‐octanol, with recoveries from the TRPO and TBP systems being much larger than that for 1‐octanol. The stoichiometry of formation of the complexes of TBP and TRPO with phthalic acid was 1:1. The apparent extraction equilibrium constant for TRPO is much larger than that for TBP. The distribution coefficient of [1,1′‐biphenyl]‐2,2′‐dicarboxylic acid is much larger than that of the other two acids using 1‐octanol as the extractant and this acid could be removed by 1‐octanol from a mixture of the three acids. The extraction equilibrium correlations obtained for the individual acid component systems can be used to predict that of the acid mixture. CONCLUSION: The extent of phthalic acid extraction by the three solvents investigated is as follows: 10% TRPO > 50% TBP > 1‐octanol. The stoichiometry of the complex formation of TBP or TRPO and phthalic acid is 1:1, and the apparent extraction equilibrium constant for TRPO is much larger than that for TBP. 1‐octanol shows a good extractive selectivity for [1,1′‐biphenyl]‐2,2′‐dicarboxylic acid as compared with phthalic and trimellitic acids. Copyright © 2011 Society of Chemical Industry     

离子液体-磷酸三丁酯体系分离盐湖卤水镁锂

将一种典型的室温离子液体(ionic liquids, ILs)1-辛基-3-甲基咪唑六氟磷酸盐作为替代溶剂用于盐湖卤水萃取锂。在该萃取体系中, 离子液体和磷酸三丁酯(TBP)分别用作萃取介质和萃取剂。详细考察了水相酸度、相比等因素对锂分离效率的影响。初步结果表明:与传统萃取体系相比, 该离子液体萃取体系能极大提高萃取效率。该体系最优条件包括: TBP/ILs=9/1(体积比), 相比O/A=2:1, 水相的pH萃取前不需要调节。在此条件下, 锂和镁的单级萃取效率分别为80.64%和5.30%。经过三级逆流萃取, 锂的萃取率高达99.42%。在温度为80℃, 反萃相比A/O为2的条件下, 锂和镁的单级反萃效率分别为98.78%和99.15%。反萃水相中的镁锂比(Mg/Li)降至3.03, 与初始值相比降低了93.41%。