磷酸三丁酯—煤油从浓缩溶液中萃取Zr的第三相行为

本文研究了磷酸三丁酯（ＴＢＰ）在煤油中从浓硝酸和盐酸溶液中对Ｚｒ（ＩＶ）的萃取，考察了室温下初始Ｚｒ浓度，ＴＢＰ浓度以及水相酸度对萃取的影响，同时确定了体系第二相的形成条件，发现酸同Ｚｒ被一同萃取，酸度越高则萃取率越大，较高的酸度和Ｚｒ（ＩＶ）浓度易使萃取有机相分相，用红外光谱研究了第三相的组成，用Ｋａｒｌ－Ｆｉｓｃｈｅｒ滴定法和电导率仪分别了第三相的水含量量和比电导，对可能的萃合物结构进行了推测     

磷酸三丁酯－煤油从浓酸溶液中萃取Zr的第三相行为

本文研究了磷酸三丁酯（ＴＢＰ）在煤油中从浓硝酸和盐酸溶液中对Ｚｒ（Ⅳ）的萃取，考察了室温了初始Ｚｒ浓度、ＴＢＰ浓度以及水相酸度对萃取的影响，同时确定了体系第二相的形成条件．发现酸同Ｚｒ被—同萃取，酸度越高则萃取率越大，较高的酸度和Ｚｒ（Ⅳ）浓度易使萃取有机相分相．用红外光谱研究了第三相的组成，用Ｋａｒｌ－Ｆｉｓｃｈｅｒ滴定法和电导率仪分别测定了第三相的水含量和比电导，对可能的萃合物结构进行了推测，认为从胶体化学看第三相可能是一种具有双连续相结构的微乳液．     

硝酸萃取传质过程中的界面弛豫研究

在萃取装置中研究了激励相界面的硝酸传质过程。该装置是一个改进的传质槽,它有保温夹套和一条穿过两相用于激励相界面的带子。硝本匠变化采用插入水相的电导仪探针检测,用录象方法记录实验中的界面现象。实验采用ＴＢＰ、ＴＯＡ和ＴＨＡ作为萃取剂,用四氯化碳,甲苯或７～１３℃烷烃做萃取溶剂。实验结果表明,激励相界面能够提高传质速率;在传质开始前对界面失要息和老化可以改变传质的初始速率。通过录象证实,激励相界面能够     

单级萃取—反萃取同时分离回收磷酸中铀和稀土

使用单级萃取－反萃取工艺，从湿法磷酸（ＷＰＡ）中回收铀和稀土的新工艺，既简单又易于控制，因为它只涉及酸性介质。该工艺是基于用二（２－乙基己基）磷酸（ＤＥＰＡ）和磷酸三丁酯（ＴＢＰ）和磷酸三丁酯（ＴＢＰ），从湿法磷酸中萃取铀和稀土。发现ＤＥＰＡ是唯一有效的，它稳定并且易于反萃取。其它的有机磷酸酯易水解，并且很难反萃取。用含有酸性氟化物的介质，对稀土和铀进行反萃取。对于铀来说，以六价（Ｕ＾６＋）形成被     

β-萘酚稀溶液萃取动力学研究

选用磷酸三丁酯 甲苯混合溶剂对β 萘酚稀溶液进行萃取动力学研究,考察了搅拌强度、二相界面积、水相β 萘酚质量浓度、水相pH值、有机相内萃取剂体积分数和温度对萃取速率的影响。实验结果表明,磷酸三丁酯萃取β 萘酚的动力学模式为化学反应控制模式,且为水相内反应控制类型。根据实验结果建立了磷酸三丁酯萃取β 萘酚的动力学模型。     

MNA-TBP从盐酸介质中萃取Ir(Ⅳ)

对ＭＮＡ－ＴＢＰ从盐酸介质中萃取Ｉｒ（Ⅳ）作了研究．结果表明：ＭＮＡ－ＴＢＰ对Ｉｒ（Ⅳ）萃取有协同效应．当ＭＮＡ和ＴＢＰ在正辛烷中的浓度各为０．４５ｍｏｌ／Ｌ，待萃液中ＨＣｌ总浓度为４ｍｏｌ／Ｌ，铱浓度为１７３．１３μｇ／ｍｌ，相比为１时，协萃系数Ｒ为２．３３，协萃合物的组成为（ＭＮＡＨ）＋．ＩｒＣｌ＄２－６．（ＨＴＢＰ）＋．     

超临界流体萃取天然产物传质模型

为开发超临界流体萃取天然产物过程简单可靠的传质理论模型,对其传质机理进行了分析,由微分质量衡算方程经合理简化得到了动力学模型的解析解.定义了新准数B_z(可以确切地表征萃取过程的动态传质状况)和特征时间t_k,当t=t_k时,-dr_c/dt取得极小值,其原因可能是由内扩散传质阻力与内扩散传质推动力（浓度差）相竞争的结果.采用此数学模型计算了完全萃取时间t_ex、萃取收率Y随时间t的变化以及流体流率Q对萃取收率Y的影响,计算结果与文献中的实验数据吻合良好.本模型简单可靠,可用于超临界流体萃取天然产物过程的预测、分析、设计、模拟和优化.     

中空纤维支撑液膜法提取林可霉素的研究

研究了反萃相预分散中空纤维支撑液膜技术提取林可霉素的传质过程,实现了林可霉素的萃取和反萃过程的耦合。研究了萃取剂(正辛醇)体积分数、林可霉素质量浓度、原料液pH对分配系数的影响,膜组件操作过程中管程流量、壳程流量对总传质系数的影响,并得到最佳操作条件,建立了数学模型。结果表明,正辛醇体积分数为80%、林可霉素质量浓度为5.5 g/L、原料液pH=11时分配系数最大。膜组件最佳操作条件,原料液∶萃取相=500∶500(mL/min)。利用传质模型求得原料侧水相传质阻力1/kW、跨膜传质阻力1/kM、反萃侧水相传质阻力1/kS在总传质阻力所占比例分别为21%、74%、6%,其中跨膜传质阻力是传质阻力主要部分。     

液-液微尺度混合体系的传质模型

针对微尺度液-液混合体系,考察了流量对膜分散萃取过程的影响,并根据传质过程方程,计算了各种条件下的传质系数和传质速率;采用现有的传质模型分别计算分散相和连续相的分传质系数,然后根据传质阻力的加合性得到总传质系数;应用理论传质系数计算传质效率,与实验值进行了比较.研究结果表明,在微尺度混合条件下,直接影响传质系数的因素是停留时间和液滴直径,传质系数随着停留时间的减小而增大.膜分散萃取的传质系数可以达到1.2×10^-4m•s^-1,比传统的萃取方式大10～100倍;不能像塔式萃取设备一样,用简单地忽略某一相的传质阻力或用总体平均的简化计算公式来计算微尺度混合的传质性能;考虑滴内滴外传质系数,并考虑时间的影响,利用现有公式分别计算滴内滴外传质系数,并采用阻力加合,可以较为准确地计算微混合条件下的总传质系数,计算值与实验值符合很好.     

PMBP和TTA协萃剂负载泡沫塑料萃取Sc^3＋,Y^3＋,Nd^3＋,Er^3＋的？…

论述了将ＭＰＢＰ和ＴＴＡ协萃剂负载于聚醚型聚氨酯泡沫塑料上,萃取微量稀土元素钪,钇,钕,铒的最佳实验条件（萃取剂浓度,温度,酸度）研究了它们的萃取性能（萃取百分率,分配比,萃取容量）说明这是可行的萃取方法。     

Mild stir-assisted membrane dispersion for enhancing propionic acid extraction

Mild stir-assisted membrane dispersion extraction (MDE) method was employed to enhance propionic acid (HA) extraction and compared to the mechanical stirred extraction (MSE) method. Triocylamine (TOA) and tributyl phosphate (TBP) were chosen as model extractant to extract HA. Firstly, droplet size and the size distribution of organic phase were analyzed, and then the effects of phase ratio, extractant and HA concentration on extraction performance were investigated. Comparing the two extraction methods, the results show mild stir-assisted MDE method reduced the mass transfer equilibrium time compared to MSE method. The mass transfer mechanism was explored by analyzing mass transfer resistance. Mild stir-assisted MDE had less total mass transfer resistance than MSE. When the extractant concentration was 40%, the extraction process was controlled by organic phase mass transfer process with HA volume fraction was 1% and controlled by both of reaction process and organic phase mass transfer process when HA concentration increased to 5%. This work may provide a new type of extraction method for the recovery of organic carboxylic acid.     

2-乙基-1，3-己二醇萃取硼酸的传质系数

单液滴法因其测量结果精确与实验设备简单等优点广泛应用于萃取过程中的传质研究。应用此方法研究了硼酸在2-乙基-1,3-己二醇-甲苯/卤水体系中的传质系数。结果表明：传质系数随着有机相2-乙基-1,3-己二醇浓度、卤水相硼酸浓度及温度的增加而增大。通过双膜传质理论分析,并引入修正的传质系数关联式,将双膜传质模型应用到此萃取体系中,建立了新的针对此体系的传质系数模型。新模型的计算值与实验值的平均相对误差为7.59 %,两者吻合良好,因此,该模型可用于2-乙基-1,3-己二醇-甲苯体系萃取硼酸过程的设计与放大。     

膜萃取去除水中对氨基苯磺酸的研究

以特定混合物 (2 0 %TOA 30 %辛醇 50 %煤油 ) -对氨基苯磺酸 -水为实验体系 ,应用中空纤维膜萃取技术处理含对氨基苯磺酸的水溶液。研究了两相流速、溶液pH、初始浓度对传质性能的影响。结果表明 ,传质由水相侧阻力控制 ,在相比(有机相 /水相 )较小的情况下 ,可使初始质量浓度为 1 0 0 0mg/L的溶液降至 30mg/L ,证明了中空纤维萃取去除水中对氨基苯磺酸的高效性。     

Phenol recovery with tributyl phosphate in a hollow fiber membrane contactor: Experimental and model analysis

The extraction and stripping of phenol using a solution of tributyl phosphate in kerosene in a hydrophobic polypropylene hollow fiber membrane contactor has been studied. The effect of the aqueous and the organic phase flow rates on the overall mass transfer coefficient for both extraction and stripping steps was investigated. Experimental values of the overall mass transfer coefficient were determined and compared with predicted values from the resistance in series model. Results showed that the overall mass transfer coefficients for extraction were about one order of magnitude greater than those measured during the stripping process. The experimental values were in good agreement with the predicted values for the extraction module. However, the predicted values were slightly overestimated for the stripping module. The individual mass transfer resistances were analyzed and the rate-controlling steps of mass transfer were also identified in both extraction and stripping modules. The major resistance in extraction and stripping was in the aqueous phase and in the membrane phase, respectively.     

G/O/W微分散体系实现甲酸/三辛胺-正辛醇体系萃取分离

以络合萃取法实现了稀溶液中甲酸的富集。确定了高分配系数的萃取体系。根据传质基本方程建立了传质模型，计算并分析了油/水体系中的传质过程，确定传质控制步骤为甲酸自水相至水/油界面的传质。计算了分散尺寸对体系传质性能的影响，结果表明，由于水/油相比高，体系的传质系数低，界面积小，以油/水微分散乳液实现萃取过程，传质效率仍不高。引入惰性气体，并构建气/油/水体系，计算并分析了气/油/水体系中的传质过程并优化了气相加入量，结果表明，气相的加入可以有效促进传质过程。设计了双重膜分散设备，制备了微米尺度的气/油/水双重乳液，并以此实现了稀溶液中甲酸的高效富集。     

Extraction of formic acid with G/O/W microdispersion system

The enrichment of formic acid in dilute solution was achieved by complex extraction method. An extraction system with high partition coefficient was determined. The continuum model was then applied for describing mass transfer process and predicting the mass transfer characteristics in O/W system. The rate-limiting step was determined to be mass transfer of formic acid in aqueous phase, by comparison of mass transfer rates between extractant in organic phase and solute in aqueous phase. The effect of dispersion size of organic droplets on mass transfer characteristics in O/W systems was determined, indicating inefficient extraction process with low mass transfer coefficients and surficial area in O/W systems. Inert gas was introduced into extraction system and a G/O/W system was developed. The calculation of mass transfer performance in G/O/W system indicates the addition of microbubbles effectively enhances the mass transfer process. Also, suitable volumetric fraction of inert gas was optimized. According to the calculation, a double-membrane-dispersion-device was designed, with which G/O/W double emulsion was prepared and effective enrichment of formic acid from its dilute solution was realized.     

New liquid membrane technology for simultaneous extraction and stripping of copper(II) from wastewater

In this paper, a new liquid membrane technique, hollow fiber renewal liquid membrane (HFRLM), is presented, which is based on the surface renewal theory, and integrates the advantages of fiber membrane extraction, liquid film permeation and other liquid membrane processes. The results from the system of CuSO₄+D2EHPA in kerosene+HCl show that the HFRLM process is very stable. The liquid membrane is renewed constantly during the process, the direct contact of organic droplets and aqueous phase provides large mass transfer area. These effects can significantly reduce the mass transfer resistance in the lumen side. Then the mixture of feed phase and organic phase flowing through the lumen side gives a higher mass transfer rate than that of stripping phase and organic phase, because the aqueous layer diffusion of feed phase is the rate-controlling step. The overall mass transfer coefficient increases with increasing flow rates and D2EHPA concentration in the organic phase, and with decreasing initial copper concentration in the feed phase. The overall mass transfer coefficient also increases with increasing pH in the feed phase, and reaches a maximum value at pH of 4.44, then decreases. Also, there is a favorable w/o volume ratio of 20:1 to 30:1 for this process. Compared with hollow fiber supported liquid membrane and hollow fiber membrane extraction processes, HFRLM process has a high mass transfer rate. Mathematical model for the HFRLM process based on the surface renewal theory is developed. The calculated results are in good agreement with experimental results under the conditions studied.     

Extraction of Uranium Nitrate with 30% (v/v) Tributyl Phosphate in Kerosene in a Pilot Annular Pulsed Disc-and-Doughnut Column—Part II: Axial Mixing and Mass Transfer Performance

Mass transfer experiments were carried out in an annular pulsed disc-and-doughnut column (APDDC) using 30% (v/v) TBP-kerosene + uranium nitrate + nitric acid + water system (uranium nitrate system) for both extraction and stripping processes. Parameters in the axial dispersion model (ADM) and plug-flow model (PFM), namely, the axial dispersion coefficient of the continuous phase and the number of mass transfer units, were regressed by correlating the respective model with the experimental concentration profile. The mass transfer coef?cient is calculated, and new correlations are developed to predict the axial mixing coefficient of the continuous phase and the volumetric mass transfer coefficient. The height of a transfer unit is also calculated. The influence of axial mixing on mass transfer performance for the uranium nitrate system is discussed.