955 resultados para CA-12


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随着萃取技术的不断发展,人们日益要求更加深入的了解萃取过程的机制及其动力学特性。以便有效地控制和强化萃取过程,提高萃取效率,或者利用萃取动力学的差异来实现某些分离嘴过程。尽管许多萃取过程进行得很快,但是人们也发现不少的金属鳌合物萃取体系,其萃取过程相当缓慢。因而这类体系的萃取机制和萃取动力学问题已日益引人注目。除此而外,在设计,放大或改进萃取设备时,研究和掌握有关萃取过程的动力学规律也有十分重要意义。在本文中主要对稀土萃取动力学进行了研究,得到主要结果如下:1.研究了硫代有机磷酸Cyan.ex302萃取饵的动力学。通过测定各种萃取条件对萃取速率的影响,获得了萃取速率方程,并讨论了萃取的控制过程。实验发现萃取剂中的杂质对萃取具有较大的加速作用,这对工业生产具有一定的实际意义。2.用两相滴定法测定了两种新合成的J梭酸萃取剂CA-12和CA-100的某些重要的物理常数。这将有助于深入研究它们的萃取性质及机理。3.用层流恒界面池研究了CA-12萃取La, Gd,Er, Yb和Y的动力学。考察了各种因素对萃取速率的影响,获得了它们的萃取速率方程,实验发现了它们的萃取控速步骤并推测了其萃取机理。4.研究了HEHEHP对CA-12萃取Yb和Y的动力学的影响。实验发现在CA一12中加入少量的HEHEHP后,萃取活化能显著降低,萃取速率明显加快。由于加入HEHEHP后,萃取Yb的活化能的降低要比萃取Y的活化能降低的程度大',所以使Yb和Y的萃取分离因素加大。5.用两相滴定法研究了HEHEHP萃取铭的机理,CA-12萃取稀土及其相关离子的机理。并计算了它们相应的平衡常数。

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用层流恒界面池研究了CA-12萃取钇的动力学。测定了搅拌速度、酸度、萃取剂浓度、温度对萃取速率的影响。测得CA-12萃取钇的活化能为48.96kJ/mol,此过程属于化学反应控制。当CA-12中加入少量的P507时,其活化能降至23.19kJ/mol。萃取过程由化学反应控制转变为扩散和化学反应混合控制。

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Although Basin and Range–style extension affected large areas of western Mexico after the Late Eocene, most consider that extension in the Gulf of California region began as subduction waned and ended ca. 14–12.5 Ma. A general consensus also exists in considering Early and Middle Miocene volcanism of the Sierra Madre Occidental and Comondú Group as subduction related, whereas volcanism after ca. 12.5 Ma is extension related. Here we present a new regional geologic study of the eastern Gulf of California margin in the states of Nayarit and Sinaloa, Mexico, backed by 43 new Ar-Ar and U-Pb mineral ages, and geochemical data that document an earlier widespread phase of extension. This extension across the southern and central Gulf Extensional Province began between Late Oligocene and Early Miocene time, but was focused in the region of the future Gulf of California in the Middle Miocene. Late Oligocene to Early Miocene rocks across northern Nayarit and southern Sinaloa were affected by major approximately north-south– to north-northwest– striking normal faults prior to ca. 21 Ma. Between ca. 21 and 11 Ma, a system of north-northwest–south-southeast high angle extensional faults continued extending the southwestern side of the Sierra Madre Occidental. Rhyolitic domes, shallow intrusive bodies, and lesser basalts were emplaced along this extensional belt at 20–17 Ma. Rhyolitic rocks, in particular the domes and lavas, often show strong antecrystic inheritance but only a few Mesozoic or older xenocrysts, suggesting silicic magma generation in the mid-upper crust triggered by an extension induced basaltic infl ux. In northern Sinaloa, large grabens were occupied by huge volcanic dome complexes ca. 21–17 Ma and filled by continental sediments with interlayered basalts dated as 15–14 Ma, a stratigraphy and timing very similar to those found in central Sonora (northeastern Gulf of California margin). Early to Middle Miocene volcanism occurred thus in rift basins, and was likely associated with decompression melting of upper mantle (inducing crustal partial melting) rather than with fluxing by fluids from the young and slow subducting microplates. Along the eastern side of the Gulf of California coast, from Farallón de San Ignacio island offshore Los Mochis, Sinaloa, to San Blas, Nayarit, a strike distance of >700 km, flat lying basaltic lavas dated as ca. 11.5–10 Ma are exposed just above the present sea level. Here crustal thickness is almost half that in the unextended core of the adjacent Sierra Madre Occidental, implying signifi cant lithosphere stretching before ca. 11 Ma. This mafic pulse, with subdued Nb-Ta negative spikes, may be related to the detachment of the lower part of the subducted slab, allowing an upward asthenospheric flow into an upper mantle previously modified by fluid fluxes related to past subduction. Widespread eruption of very uniform oceanic island basalt–like lavas occurred by the late Pliocene and Pleistocene, only 20 m.y. after the onset of rifting and ~9 m.y. after the end of subduction, implying that preexisting subduction-modified mantle had now become isolated from melt source regions. Our study shows that rifting across the southern-central Gulf Extensional Province began much earlier than the Late Miocene and provided a fundamental control on the style and composition of volcanism from at least 30 Ma. We envision a sustained period of lithospheric stretching and magmatism during which the pace and breadth of extension changed ca. 20–18 Ma to be narrower, and again after ca. 12.5 Ma, when the kinematics of rifting became more oblique.

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本文研究了一种中性萃取剂支链三烷基氧化膦(Cyanex 925)和一种羧酸类萃取剂仲辛基苯氧基取代乙酸(CA-12)萃取稀土元素和钇的热力学性能。探讨了利用CA -12为萃取剂将钇与其他稀土分离的可行性,遵循基础-应用的原则,完成了从龙南离子型矿的浸出液中提取钇的分馏串级模拟实验。在此基础上还进一步研究了“绿色溶剂”离子液为溶剂,CA-12萃取稀土和钇的热力学机理。我们还考察了双水相中氨基酸的分离,为利用双水相体系萃取稀土元素奠定了一定的基础。具体的研究内容如下: 1.系统的研究了Cyanex 925在硝酸体系中萃取稀土和Y的规律,由斜率分析方法确定了反应机理,发现了明显的四分组效应,并确定了Y在萃取中所处的位置。同时发现Cyanex 925有可能用于轻、重稀土分组,易反萃。 2.CA-12对Y萃取具有高的选择性,研究了Y与其他稀土分离的可能性。进行了CA-12从混合稀土中提取Y的工艺模拟实验,并获得纯度为99.5%Y2O3,该工艺高效简便,具有好的应用前景。 3.系统的研究了离子液作为溶剂,CA-12从硝酸介质中萃取稀土和Y的规律。考察了不同水相酸度、水相中相关各种离子及萃取剂浓度变化对CA-12萃取稀土和钇的影响,从而推导了萃取反应方程式及机理。并发现在同样萃取剂浓度和水相条件下,CA-12-离子液体系中萃取稀土和钇的能力低于CA-12-庚烷体系中。 4.研究了赖氨酸、蛋氨酸、苯丙氨酸和半胱氨酸在聚乙二醇(PEG)-磷酸盐双水相体系(ATPSs)中分配行为,分别考察了PEG分子量、水相pH、氨基酸侧链结构等对分配比的影响,得出氨基酸在双水相中的分配行为取决于双水相体系的性质和氨基酸的支链结构与带电情况。

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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。

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本论文利用高效离心分配色谱仪进行了稀土元素抗、忆、斓的分离研究和菱角壳中黄酮类化合物的分离研究;探讨了氨基酸在双水相体系中的分配行为;利用气相色谱一质谱法测定了野生菱角壳中的多糖类化合物的组成;利用高效制备色谱法对野生菱角壳中的黄酮类和生物碱类化合物分别进行了制备分离的研究。1.首次采用新型梭酸类萃取剂CA-12(仲辛基苯氧基乙酸)的庚烷溶液作为固定相,以氯乙酸一氢氧化钠混合溶液为流动相,利用高效离心分配色谱(HPCPC)分离伉、铭、斓,考察了流动相酸度、流速及HPCPC转速对分离效率的影响,通过梯度PH洗脱,实现了杭、忆、悯的基线分离,并对CA-12萃取金属离子的机理进行了探讨,同时利用HPCPC,对黄酮类化合物进行了分离研究,优选出溶剂系统(正己烷一乙酸乙醋一甲醇一水)的最佳配比,实现了混合物的分离。2.首次对四种氨基酸在聚乙二醇(PEG)一磷酸盐双水相体系中的分配行为进行了研究。考察了PEG分子量、磷酸盐溶液的pH值对相图的影响,测定了两相的组成、密度和折射率等参数,并对缓冲溶液的pH值、盐离子的存在和氨基酸的支链结构对氨基酸在双水相中分配比的影响进行了探讨。3.用乙醇分级沉淀法,首次从野生菱角壳中提取出多糖化合物。通过Molisch试验、红外光谱、核磁共振波谱分析确定了多糖的存在,用气相色谱一质谱法,确定了菱角壳多糖化合物的单糖组成。首次从野生菱角壳中提取出黄酮类化合物和生物碱类化合物,利用高效制备液相色谱(HPLC),通过考察流动相的组成配比、流速、检测波长等分离条件对分离效果的影响,优选出最佳色谱分离条件和制备条件,分离制备出四个黄酮化合物和三个生物碱化合物单组分,经化学法、红外光谱、质谱法和核磁共振法等初步确定了黄酮类化合物和生物碱类化合物的基本结构单元。

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本论文以有效的萃取和分离稀上元素为目的,研究和开发了几种新的有效的协同萃取体系,并详细研究了其对稀土元素的萃取和分离性能,在热力学研究的基础上进一步考察其动力学和界面性质,为其在实际中的应用奠定基础;同时探讨了加入氨梭络合剂的方法实现稀土元素的分离。研究了有机腾酸类萃取剂cyanex272与有机梭酸类萃取剂CA-100、CA-12构成的协同萃取体系,考察了混合体系在盐酸介质中对稀土元素的协同萃取规律,详细研究了它们对Y,Er,Sc单独及协同萃取的反应机理及反萃性能,稀土元素之间的分离系数表明:此体系对稀土元素具有较好的选择性。2.研究了有机磷酸类萃取剂EHEHPA与中性萃取剂Cyanex923协同萃取体系对稀土元素的协萃效应规律,并考察了其对La,Nd,Gd的协萃反应机理及反萃取性能,讨论了稀土的分离可能性。3.采用加入氨梭络合剂的方法改进单独的CA-100体系,对两种料液进行实验,确定最佳分离条件,研究表明:本方法适合于选择性分离和提纯含有少量重稀土杂质的Y溶液,具有很好的应用前景。4.研究了CA-100+Cyonex272协同萃取Y,Yb的动力学性质,通过考察各种因素对萃取速率的影响,确定其对Y,Yb的萃取动力学为扩散控制过程,并得到了其对从Yb的萃取速率方程,讨论了Y,Yb动力学分离的可能性。5.研究了CA-100+Cyanex272-庚烷体系的界面性质,讨论了水相酸度、温度、稀释剂等各种因素的对界而性质影响,发现此体系具有良好的界面性质,能够定性地解释其协同萃取稀土的热力学和动力学特征。

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本硕士沦文籍助兰州重离子加速器国家实验室分离扇聚焦回旋加速器(SFC)提供的重离子束通过全融合蒸发反应产生远离口稳定线的缺中子核素,并用本课题组发展和建立的氦喷嘴快速带传输系统以及多重符合测量装置分离、测量核素来研究其衰变性质。在实验准备期间,曾采用~(252)Cf源进行了氦喷嘴(I-I eje咧央速带传输系统效率的测定。给出了PbI_2,PbCl_2,NaCl三种无机欲添加剂的传输效率,以及传输效率随目标核质量变化的初步结果。而后完成了以下两项物理实验:~(113)Sm的(EC+β~+)衰变纲图和133Pr的同核异能态的研究:用SFC引出的~(40)Ca~(12+)束流轰击96%Ru的浓缩同位素靶,采用氦喷嘴带传输系统和x-γ与γ-γ符合测量方法,首次建议了~(133)Sm的简单的(EC+β~+)衰变纲图并测得了其β衰变半衰期。~(133)Sm是目前发表过(EC+β~+)衰变纲图的最轻的钐(Sm的缺中子核。由于Ru靶中含有~(98-102)Ru的成分,同时产生了~(133)Pr,并首次测定了~(133)Pr 11/2~-同核异能态的寿命为(l.1±0.2)s。为Pr奇A核11/2~-同核异能态的数据作了重要的补充,汇编成Pr奇A核的11/2一同核异能态和与之相关的3/2~+,5/2~+和7/2~+能级的系统性数据。用单粒子模型理论拟合从中提取了~(131,133,135,137)Pr的11/2~-同核异能态的约化跃迁概率的实验值,并与Weisskopf近似估计进行了比较。2.~(93)Pd的β缓发质子衰变:通过~(58)Ni(~(40)Ca,3n2p)反应合成β缓发质了先驱核~(93)Pd,采用氦喷嘴带传输系统加p-γ符合观测到了它的β缓发质子衰李,测得其半衰期为1.3±0.2s。采用统计模型计算拟合了实验测得的口缓发质子能谱和布居到质子发射体子核不同终态的分支比,首次由实验数据出发初步指认了93Pd的基态自旋-宇称为9/2~±。同时与采用Woods-Saxon Strutinsky方法计算~(93)Pd的核位能面得到的结果进行了比较。计算结果支持对~(93)Pd基态自旋一宇称为9/2~+的实验指认。

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Extraction and separation of yttrium from the rare earths in chloride medium using sec-octylphenoxy acetic acid (CA-12), tri-n-butyl phosphate (TBP) as modifier, in kerosene has been investigated. The separation coefficients, beta, were obtained and the extraction selectivity has been enhanced when compared with that of naphthenic acid. The experimental results indicated that CA-12-TBP system could be employed to separate yttrium, from rare earths. Fractional extraction (15 stages for extraction and 10 stages for scrubbing) was studied, the raffinate of the first stage was abundant in purity yttrium of 99.5%, with a yield of > 95%, percentage of yttrium in the mixture rare earths was less than 5% in the loaded organic phase of the 25th stage and loaded capability was about 0.2 mol/L.

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Separation of scandium(III), yttrium(III) and lanthanum(III) was performed by high-performance centrifugal partition chromatography (HPCPC) employing the stationary phase of S-octyl phenyloxy acetic acid (CA-12). The liquid-liquid extraction behavior of CA-12 for Sc(III), Y(III) and La(III), the acidity of aqueous phase, and the operation conditions of HPCPC were examined. The retention volume (V-R) increased with the order of Y(III), La(III) and Sc(III) accompanied with the elution of the mobile phase in different pH, which is lowered from 4.6 to 2.1.

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采用溶剂萃取法 ,研究了一种新型萃取剂———仲辛基苯氧乙酸 (CA -12 )从盐酸介质中萃取Co(Ⅱ )的性能。考察了萃取温度、平衡水相酸度、萃取剂初始浓度、氯离子初始浓度、钴离子初始浓度对萃取的影响。实验结果表明 :分配比随平衡水相酸度的增加、萃取剂初始浓度的减小、温度的降低而减小 ;水相中氯离子、钴离子初始浓度对分配比基本上没有影响 ;仲辛基苯氧乙酸从盐酸介质中萃取Co(Ⅱ )的过程为吸热过程 ,并计算得到其过程热△H =9 0 2kJ/moL。

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采用溶剂萃取法 ,研究了一种新型萃取剂———仲辛基苯氧乙酸 (CA -12 )氨化后从盐酸介质中萃取Cu(Ⅱ )、Co(Ⅱ )、Ni(Ⅱ )的机理。确定了萃取反应的机理、萃合物的组成及萃取反应的平衡常数。并经红外光谱确证了氨皂化的CA -12从盐酸介质中萃取Cu(Ⅱ )、Co(Ⅱ )、Ni(Ⅱ )的机理

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采用溶剂萃取法 ,研究了新型萃取剂——仲辛基苯氧乙酸 (CA- 12 )从盐酸介质中萃取Cu( )的性能。考察了萃取温度、平衡水相酸度、萃取剂初始浓度、氯离子浓度、铜离子浓度对萃取的影响。实验结果表明 :分配比随平衡水相酸度的增加、萃取剂初始浓度的减小而减小 ;水相中氯离子、铜离子 ( )初始浓度对分配比均有明显的影响 ;仲辛基苯氧乙酸从盐酸介质中萃取 Cu( )的过程为吸热过程 ,并计算得到其过程热 Δ H=12 .77k J/ mo

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采用溶剂萃取法 ,研究了一种新型萃取剂———仲辛基苯氧乙酸 (CA— 12 )从盐酸介质中萃取Fe(Ⅲ )的性能。考察了萃取温度、平衡水相酸度、萃取剂初始浓度等对萃取的影响。实验结果表明 :分配比随平衡水相酸度的增加、萃取剂初始浓度的减小、温度的升高而减小。仲辛基苯氧乙酸从盐酸介质中萃取Fe(Ⅲ )的过程为放热过程 ,并计算得到其过程热ΔH =-2 .2 1kJ mol。