232 resultados para PHOSPHINE OXIDE CYANEX-923
Resumo:
A mild and efficient copper-catalyzed system for N-arylation of alkylamines and N-H heterocycles with aryl iodides using a novel, readily prepared and highly stable oxime-functionalized phosphine oxide ligand was developed. The coupling reactions could even be performed in solvent-free conditions with moderate to good yields. (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
The extraction behavior of lanthanides and yttrium usinsg CYANEX 925 (mixture of branched chain alkylated phosphine oxides) in n-heptane from nitrate medium has been studied. The effects of aqueous phase ionic strength, CYANEX 925 concentration in the organic phase, and temperature on Sm3+, Nd3+ and Y3+ extraction have been investigated. The extractability of the lanthanides and yttrium increases with increasing nitrate concentration, as well as with increasing CYANEX 925 concentration. An extraction mechanism is proposed based on slope analysis. Furthermore, the infra-red spectra of CYANEX 925 saturated with lanthanides are employed to provide evidence of the composition of the complex. The relationship between the logarithm of the distribution ratio and lanthanide atomic number is also discussed which indicates that yttrium can be separated from fight lanthanides. In addition separation of the light and heavy lanthanide groups is also possible using CYANEX 925. From the temperature dependence data, the thermodynamic parameters values (Delta H, Delta S and Delta G) are calculated.
Resumo:
The synergistic extraction of Sc(III) from H2SO4 solution with bis(2, 4, 4-trimethylpentyl)monothiophosphinic acid(HBTMPTP, HL) and branched chain alkyl phosphine oxide mixture (Cyanex 925, B) in n-hexane has been investigated, The results indicated that synergistic effect was showed in low acidity (c(H2SO4) < 0.25 mol/L). The composition of the extracted complex of Sc(III) has been determined to be Sc(HL2)(2)B-3(SO4)(1/2) by the method of slope analysis, The mechanism of the synergistic extraction of Sc(III) may be : Sc3+ + 2(HL)(2(O)) + 3B((O)) + 1/2SO(4)(2-)reversible arrow(K12)Sc(HL2)(2)B-3(SO4)(1/2(O)) + 2H(+) ScL(HL2)(2(O)) + 3B((O)) + H+ + 1/2SO(4)(2-)reversible arrow(beta')Sc(HL2)(2)B-3(SO4)(1/2(O)) + 1/2(HL)(2(O)) Sc(SO4)(1.5)B-2(O) + B-(O) + 2(HL)(2(O))reversible arrow(beta')Sc(HL2)(2)B-3(SO4)(1/2(O)) + 2H(+) + SO42- Their equilibrium constants have been calculated to be lgK(13)=6.77+/-0.12, lg beta'=7.71, lg beta '' = 0.10, respectively, The IR spectra and FAB-MS of the saturated synergistic extraction complex of Sc(III) have been discussed as well.
Resumo:
The extraction and separation of Ho, Y, and Er(III) with the mixtures of bis(2,4,4-trimetylpentyl)monothiophosphinic acid (Cyanex 302) and another organic extractant, such as acidic organic extractant (di-2-ethylhexyl phosphoric acid P204, 2-ethythexyl phosphoric acid mono-2-ethylhexyl ester P507, di-2-ethylhexyl phosphinic acid P229, and sec-nonylphenoxy acetic acid CA-100), neutral organic extractant (tri-n-butyl phosphate TBP, di-(1-metylheptyl)metyl phosphate P350, and branched trialkylphosphinic oxide Cyanex 925) or primary amine N1923, has been investigated in this paper. The extractability and separation ability for the Ho, Y, and Er with the mixtures of Cyanex 302 and organic extractants has been compared. The synergistic effect of the Ho, Y, and Er extraction with the mixtures of Cyanex 302 and P229, Cyanex 925, CA-100, or N1923 has been explored and the synergistic enhancement coefficients have been calculated. At last, the Y3+ synergistic extraction with the mixtures of Cyanex 302 and CA-100 has been determined and the extracted complex has been deduced.
Resumo:
本文研究了中性萃取剂三烷基氧化膦(Cyanex 923)从硫酸介质中萃取与反萃三价稀土Yb(III)的热力学和动力学机理,对该萃取剂的界面活性进行了深入的研究,并详细探讨了其从硫酸介质中萃取Ce(IV)时液/液界面的吸附参数及萃合物的聚集。此外,还考察了一种羧酸类萃取剂仲辛基苯氧基取代乙酸(CA-12)所组成的萃取有机相中W/O微乳液的热力学稳定性与结构参数。 1. 研究了Cyanex 923从硫酸介质中萃取与反萃Yb(III)的热力学。考察了一些影响萃取与反萃的条件,如:酸度、盐析剂、温度、反萃剂种类等,得出了萃取机理与热力学函数,为分离Yb(III)与其它稀土元素提供了有用的参数。 2. 研究了Cyanex 923 从硫酸体系中萃取Yb(III)的动力学,通过考察搅拌强度、比界面积、温度、反应物浓度等各种因素对萃取速率的影响,确定其对Yb(III) 的萃取动力学为扩散控制过程,反应主要在液/液界面进行,控制步骤为反应物种通过界面凝滞膜的界面扩散过程,并推导出了萃取速率经验式。 3. 考察了温度、离子强度、酸度、添加剂和不同稀释剂对萃取剂Cyanex 923在Cyanex 923-稀释剂/Na2SO4-H2SO4界面的界面活性的影响,得到了Cyanex 923在不同条件下的界面吸附参数,对萃取剂界面活性与萃取动力学的关系进行了讨论。 4.考察了Cyanex 923-正庚烷/Ce(IV)-H2SO4 萃取体系在液/液界面的吸附参数,重点研究了体系的界面活性物种、萃合物聚集造成的界面现象及其对溶剂萃取过程的影响,详细地研究了Ce(IV)和H2SO4的萃取对萃取体系一些物化性质的影响,观测到了萃取体系中反胶束的存在。 5. 研究了皂化CA-12—添加剂组成的萃取有机相中W/O微乳液的热力学稳定性,考察了皂化率、电解质本性与浓度、pH值、温度对体系最大加溶水量的的影响,并考查了不同添加剂与含水量时微乳液形成的热力学函数及结构参数。
Resumo:
针对Cyanex 923萃取分离铈、钍、稀土过程中Ce(IV)在萃取过程中被有机相中的还原性物质还原的问题,提出采用高锰酸钾氧化萃余水相中的Ce(III)。研究结果表明,在酸性条件下,高锰酸钾能有效的氧化水相中的Ce(III),但在萃取过程中,高锰酸根会先于Ce(IV)被萃入到有机相中,从而失去氧化Ce(III)的能力,由此提出氧化过程必须无含Cyanex 923有机相存在并参与设计了一套油水分离氧化装置。经过高锰酸钾氧化后,萃余水相中铈可低于0.5g/L,铈收率达到98%。 针对攀西氟碳铈矿新流程中直接制备的纳米级氟化铈,考察了氟化铈的紫外吸收性能,发现其在254nm处有特征吸收峰,还考察了分散剂的极性强弱、分散物浓度、粒径、温度及表面包覆等因素对紫外吸收性能的影响;发现随着粒径的减小,紫外吸收峰发生明显的红移;经TiO2包覆后CeF3的紫外吸光域范围扩展。 研究了Cyanex 923与P204组成的双溶剂萃取体系及其单独体系萃取Ce(IV)、F及Ce(IV)-F混液的热力学性质,得出了协同萃取机理,获得了萃取平衡方程式以及协萃物的组成。研究发现混合体系对Ce(IV)及Ce(IV)-F混液中的Ce、F均有明显的协萃作用,这为该萃取体系应用于现实分离中提供了可靠的保证。 在上述工作的基础上,提出了Cyanex 923与P204组成的双溶剂萃取体系分离攀西氟碳铈矿的新清洁冶金流程。对影响这一流程的化学因素进行了系统研究,并给出了工艺运行参数。
Resumo:
本论文共分六章,论文首先综述了近年稀土溶剂萃取最新出现的一些萃取体系及萃取方法,然后用溶剂萃取法系统研究了新萃取剂 PT-2 萃取稀土(III)、Cyanex 923 和 Cyanex 925 萃取铈(IV)、钍和稀土(III)的性质,推导层流型恒界面池的理论基础并用恒界面池法研究 Cyanex 272、PT-2 萃取稀土动力学,用高效离心分配色层仪(HPCPC) PT-2、Cyanex 302 和 Cyanex 272-P507 混合体系分离稀土(III)的规律,本论文还在大量实验数据的基础上,提出从氟碳铈矿中提取稀土的具有创新性的绿色工艺流程。论文第一章综述了近年衡土溶剂萃取的研究成果,为探求优于应用于工业生产的萃取稀土(III)的 P507 体系以及萃取钇的环烷酸体系,人们合成大量的有机磷类、羧酸类、苯胲类萃取剂并研究了它们萃取稀土的性能,将现有的萃取剂进行优化组合得到许多稀土的协同萃取体系,还将结晶反萃、还原反萃等方法应用于稀土分离过程。第二章用两相滴定法在测定 PT-2 的 K_d、K_2 等基本常数基础上,研究了 PT-2 的正庚烷溶液在盐酸、硝酸介质中萃取 15 个稀土离子(除了 Pm 外)的分配规律及萃取机理,同硫酸体系、高氯酸体系萃取平衡进行了对比,得到一些在理论上和实际上很有价值的结果。首次发现高位阻的酸性膦酸类萃取剂 PT-2 萃取轻、重稀土(III)时存在不同的机理,在盐酸、硝酸和硫酸体系中, PT-2 萃取轻稀土(III)为阳离子交换机理, PT-2 萃取重稀土时,阳离子交换机理和溶剂缔合机理共存;高氯酸介质中,由于高氯酸根离子难以同稀土(III)形成络合物, PT-2 萃取稀土(III)的机理符合一般的酸性膦酸酯的萃取规律,为阳离子交换机理。第三章探求了多种纯化 Cyanex 923 和 Cyanex 925 的途径,得出了较为行之有效的纯化方法,系统地研究了 Cyanex 923 从硫酸和硝酸介质中萃取 Ce(IV)、Th、La 和 Gd的规律,确定了萃合物的组成,计算了 lgK、ΔG、ΔH、ΔS 等热力学常数。 Cyanex 923 对 Ce(IV)、 Th(IV)的萃取在高酸度时随酸度的增大而降低,而 Ce(IV)、 Th(IV)同时萃取时, Th(IV)的萃取受到 Ce(IV)的抑制。发现 Cyanex 923 是一种良好 Ce(IV)的萃取剂,可用于铈从稀土(III)、钍中的分离、富集,具有很好的应用前景。第四章在层流型恒界面池的传质过程理论研究基础上,研究了二 (2,4,4-三甲基戊基)膦酸(HBTMPP)、PT-2 萃取 Er(III)的动力学,测定了流体线性流速、有机相浓度、水相浓度和酸度、温度及界面面积等因素对萃取速率的影响,对萃取的控制模式作出判断,为 Cyanex 272、 PT-2 在稀土湿法冶金中的应用提供基础参数。推导出层流型恒界面池中扩散控制模式下的萃取过程善于传质量和扩散层厚度两个基本公式。PT-2 萃取 Er(III)的过程属于扩散控制模式,在不同参数(温度、线性流速、界面面积、两相组成等)条件下,以 ln[(1/β + 1)C_b~a/C_(b,0)~a - 1/β] 对时间 t 作图得到都为直线,这些参数的变化对萃取的控制模式没有影响。萃取速率随温度、线性流速、界面面积等的变化规律也表明,该萃取过程为一扩散控制模式。根据萃取速率随线性流速、界面面积和温度的影响推断 HBTMPP 萃取 Er(III)为扩散控制和化学反应共同作用的混合控制模式。利用稳态法推导出该萃取过程的初始速率方程,该速率方程能和实验结果较好吻合。第五章用 HPCPC 研究 PT-2、Cyanex 302 及 Cyanex 272-P507 体系分离重稀土元素,评估 HPCPC 的性能及萃取剂的萃取性能,考察了流动相的流速、 pH 及 HPCPC 的转速等对分离效率的影响,并对这些体系萃取重稀土(III)的机理进行了探讨。发现流速对 HPCPC 的分离效率有显著的影响,随流速的增大,理论板数降低,分离度减小;理论塔板数和分离度随转速的变化无明显的变化;在 D 值相同时, Vs/Vm 越小,理论塔板数 N 越大;pH 越高,D 越大,理论塔板数则越低;萃取剂的浓度越高,理论塔板数越低。用 HPCPC 梯度洗脱法在 Cyanex 302 体系中只经过一次运行可将轻、重稀土混合物 La(III)、Sm(III)、Dy(III)和 Tm(III)分离。第六章针对攀西稀土矿 冶炼工艺中存在由于稀土收率低、放射性钍未得到分离和利用、存在二个放射性废渣和放射性废水等问题,采用溶剂萃取法,从攀西矿氧化焙烧-硫酸浸出液中萃取分离钍和铈(IV)。研究了 N1923 从氟碳铈矿硫酸浸出液中萃取分离钍和铈(IV)的工艺,并在此基础上提出从攀西矿中萃取分离铈(IV)、钍和提取氯化稀土的流程 I。用 N1923 萃取铈(IV)、钍,稀硫酸为洗液,形成含四价铈及钍的有机相和含三价稀土元素的萃余液,实现铈、钍与三价稀土的萃取分离。由于用含过氧化氢的硫酸溶液反萃铈(IV)困难,用含过氧化氢的硝酸溶液反萃铈(IV)、钍,再以 Cyanex 923 萃取钍,实现钍和铈(III)的分离。还研究了用 S501 萃取萃取铈(IV)工艺,以稀硫酸为洗液,用含过氧化氢的硫酸溶液为反萃取液反萃铈(IV)。解决了萃取过程铈(IV)的还原性问题;探明了氟离子对萃取过程的影响以及在料液、洗液、反萃取液中加入硼酸的作用,在大量数据的基础上提出了工艺的各成分的组成。
Resumo:
本论文遵循基础一应用一基础的研究思路,围绕“攀西稀土矿饰、牡、稀土萃取分离流程”开展了工作。为该流程的工业试验提供了重要参数,并系统研究了萃取过程的热力学和动力学机理,发现了一种完全不同于传统协萃效应的被萃物质之间的协同效应,并利用萃取第三相制备了纳米粉。1、首次将伯胺萃针工艺应用于攀西矿,为工业试验提供了重要参数并在工业试验中得到验证;优化了Cyanex 923萃饰流程的工艺参数,去除了反萃段分离牡工艺,使流程大大简化。2、首次模拟攀西氟碳饰矿料液系统研究了复杂体系中Cyanex923萃取饰和氟的热力学,推导了萃取过程中的化学反应,为萃取分离和回收氟提供了理论依据,硼酸使氟的萃取率明显上升,即硼酸对萃取氟存在热力学协同效应。3,得出了Cyanex 923萃取饰以及饰和氟的动力学方程,推导了界面反应机理,首次发现了单一萃取剂体系中被萃物质之间存在动力学协萃效应,即氟使萃取饰的速率明显加快。硼酸对萃取饰的动力学没有影响。4、揭示了Cya1eX923萃取硫酸或硫酸饰溶液过程中出现第三相的机理和三相的相行为,发现萃取剂浓度越高,形成第三相的临界水相酸度越高,饰的引入也使临界水相酸度升高。首次利用萃取第三相制备了纳米级氧化饰粉末。
Resumo:
The photophysical properties of the complex Sm(PM)(3)(TP)(2) [PM = 1-phenyl-3-methyl-4-isobutyryl-5-pyrazolone, TP = triphenyl phosphine oxide] are determined in crystal state, and energy transfer process is modeled for ligands to center Sm(III) ion. The characteristic luminescence of Sm(III) is sensitized by PM and TP, and most of transitions from excited state (4)G(5/2) of Sm3+ are detected.
Resumo:
The crystal structure of Er(PM)(3)(TP)(2) [PM = 1-Phenyl-3-methyl-4-isobutyryl-5-pyrazoloiie, TP = triphenyl phosphine oxide] was reported and its photoluminescence properties were studied by UV-vis absorption, excited, and emission spectra. The Judd-ofelt theory was introduced to calculate the radiative transition rate and the radiative decay time of 3.65 ms for the I-4(13/2) -> I-4(15/2) transition of Er3+ ion in this complex.
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Selective extraction-separation of yttrium(Ill) from heavy lanthanides into 1-octyl-3-methylimidazolium hexafluorophosphate ([C(8)mim][PF6]) containing Cyanex 923 was achieved by adding a water-soluble complexing agent (EDTA) to aqueous phase. The simple and environmentally benign complexing method was proved to be an effective strategy for enhancing the selectivity of [C(n)mim] [PF6]/[Tf2N]-based extraction system without increasing the loss of [C(n)mim](+). (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
The formation of reversed micelles and the roles of extractant and extracted complexes were investigated in the Cyanex923/n-heptane/H2SO4 system. Interfacial tension (gamma), electrical conductivity (kappa), and water content measurements showed that Cyanex923 had a tendency to self-assemble, forming reversed micelles. The changes in electrical conductivity with concentration of H2SO4 in the organic phase (CH2SO4,(0)) exhibited an S-type curve: a correlation was found between the change in electrical conductivity and the water content as a function of CH2SO4,(0),.
Resumo:
利用Cyanex 923萃取法制备了纳米级CeF3微粉,并研究了分散剂、CeF3量、CeF3预处理灼烧温度和微粉粒径分布等因素对CeF3紫外吸收行为的影响。结果表明,CeF3在255 nm附近有特征吸收峰;分散剂的极性强弱、分散物浓度的改变都会影响吸收峰的强弱;随着粒径的减小,紫外吸收峰发生明显的红移。此外还研究了TiO2包覆CeF3的紫外吸收性质,复合材料在250~400 nm区间内同时出现了TiO2和CeF3的特征吸收峰,复合材料的吸光域范围扩展。
Resumo:
in this communication, a novel Er3+ complex Er(PT)(3)TPPO [PT = 1-phenyl-3-methyl-4-tert-butylbenzoyl-5-pyrazolone, TPPO = triphenyl phosphine oxide] is successfully synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. Its optical properties and the energy transfer process from the ligand PT to the Er3+ ion are investigated, the typical near-infrared (NIR) luminescence (centered at around 1530 nm) is attributed to the I-4(13/2) -> I-4(15/2) transition of Er3+ ion which results from the efficient energy transfer from PT to Er3+ ion (an antenna effect). The wider full width at half maximum (78 nm) peaked at 1530 nm in the emission spectrum and the Judd-Ofelt theory calculation on the radiative properties suggest that Er(PT)(3)TPPO should be a promising candidate for tunable lasers and planar optical amplifiers.
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BACKGROUND: Ionic liquids (ILs) as environmentally benign solvents have been widely studied in the application of solvent extraction. However, few applications have been successfully industrialized because of the difficult stripping of metal ions or the loss of components of the ILs. More work needs to be done to investigate the extraction behaviour of IL-based extraction systems. In this work, the extraction behaviour of Ce(IV), Th(IV) and some trivalent rare earth (RE) nitrates by di(2-ethylhexyl) 2-ethylhexylphosphonate (DEHEHP) in the IL, 1-methyl-3-octylimidazolium hexafluorophosphate ([C(8)mim]PF6), was investigated and compared with that in the n-heptane system. In particular, the effect of F(I) on the extraction mechanism for Ce(IV) and its separation from Th(IV) was investigated. Otherwise, the recovery efficiency of Ce(IV) and F(I) from a practical bastnasite leach liquor was examined using IL based extraction.