摘要:

Liquid-liquid extraction can often be a viable alternative to distillation for the separation of liquid mixtures. While it does not enjoy the support of confirmed, reliable methods for scaleup and design, as is the case for distillation, it does offer a potential for energy reduction and also can handle temperature-labile materials. The purpose of this paper is to provide an overview of extraction principles and applications that should be useful for conceptual design of new processes under development.

ISSN:0736-6299    

DOI:10.1080/07366298408918451

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A spline function has been employed to interpolate liquid-liquid distribution data by producing a function representing a smoothed curve through the points. The data for divalent metal extraction by trioctylamine, tributyl-phosphate and hydroxyoxime are examined in order to test the utility of interpolation with this function.

ISSN:0736-6299    

DOI:10.1080/07366298408918452

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The electrophoretic mobility (EM) of hexane and toluene droplets dispersed in aqueous solution has been investigated as a function of pH in the presence and absence of 5,8-diethyl–7–hydroxy–6–dodecanone oxime (the active extractant in the Henkel reagent, LIX63), Dinonylnaphthalene sulfonic acid (HDNNS), di(2-ethylhexyl) phosphoric acid (HDEHP) and tricaprylyl methyl ammonium chloride (Aliquat 336). Both hexane and toluene droplets were found to be negatively charged at pH > 3, with the absolute EM increasing with pH; the toluene droplets were more negatively charged than the hexane droplets. The hydroxyoxime reagent had no significant effect on the EM, whereas the addition of HDNNS and HDEHP dramatically enhanced the negative charge at the organic/ water interface. In the presence of 1·5 × 10−4kmol m−3Aliquat 336, the organic drops became less negatively charged and eventually acquired a positive charge at pH < 9. The results are explained In terms of the preferential adsorption of the aqueous phase hydroxyl ions and the polar groups of the various extractants at the organic/water interface.

ISSN:0736-6299    

DOI:10.1080/07366298408918453

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

An analysis of the induced shifts in the nuclear magnetic resonance spectra of extractants complexed to paramagnetic lanthanide ions has been carried out. The complexes of a number of monofunctional and bifunctional extractants have been examined and assigned solution structures by minimizing the differences between the observed shifts and those calculated using a computer analysis in which the potential configurations of the complexes were generated. Complexes of monofunctional extractants were calculated to have coordination geometries quite similar to those observed in related compounds by crystallographic techniques. For the bifunctional extractants, differentiation between monodentate and bidentate coordination seems possible

ISSN:0736-6299    

DOI:10.1080/07366298408918454

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The coextraction of technetium with uranium in TBP/HNO systems has been studied. The extraction mechanism,

ISSN:0736-6299    

DOI:10.1080/07366298408918455

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Pa( V ) was extracted from perohloric-perchlorate of 1M ionic strength solution at different temperatures. Thermodynamic parameters of PaO( OH) [ H( DEHP)2]2formed In the organic phase were calculated and discussed. Some organophosphorus compounds : trloctyl phosphlne oxide ( TOPO) : triphenylphosphine oxide ( TPPO; and tributyl phosphate ( TBP) were used as adducts mixed with HDEHP for Pa( V ) extraction. The distribution ratio studies suggest the following species in the organic phase : PaO( OH) [H( DEHP )2]9.TOPOt PaO( OH) [ H( DEHP) ]2. TPPO and PaO( OH ) [ H( DEHP)2]2PaO( OH) [ H( DEHP) ]22TBP. The data obtained Tor δ H, δ G and δ S of the synergistic speoles were discussed and the reaction mechanisms were proposed. Antagonism was observed in the extraction by HDEHP-TBP at low concentrations of the TBP.

ISSN:0736-6299    

DOI:10.1080/07366298408918456

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The basic extraction study on the separation of fission product molybdenum-99 and uranium in sulfuric acid solution by tri-n-octylamine in kerosene has been investigated. The equilibration time and the effect of temperature, concentration of extractant, uranium and sulfuric acid concentration on this extraction system were examined. The optimum conditions for the coextraction of molybedum-99 and uranium have been obtained with the overall recovery of 90% for99Mo and greater than 99% for uranium. Based on the complex stability difference between UO2(VI) and MoO2(VI) with TOA, uranium in the organic phase can be back-extracted by proper chloride concentration. On the other hand, molybedum-99 can be stripped from the organic phase by sodium carbonate or ammonium hydroxide solution.

ISSN:0736-6299    

DOI:10.1080/07366298408918457

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The extraction of europium(III) with 15-crown-5 (15C5), benzol-crown-6 (B15C5), 18-crown-6 (18C6) or dibenzo-18-crown-6(DB18C6) and picrate anion into chloroform was measured at 25°C. It was found that the stoichlometry in the species extracted is 1:2:3 with respect to europium(III), each crown ether employed and picrate ion. The extraction constants defined as Kex=([EUE2A3])o/[Eu3+]a)x[E]a-2[A-a-3were measured to be 108.2, 1011.1, 1013.3, and 1013.3for 15C5, B15C5, 18C6, and DB18C6, successively.

ISSN:0736-6299    

DOI:10.1080/07366298408918458

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Metal separations from various mixtures of alkali metal, alkaline earth metal, Cu2+, Zn2+, Ag+, Tl+, and Pb2+nitrates were studied using an emulsion membrane system. The membrane consisted of a water-in-oil emulsion composed of 0·050 M LI4P2O7In H2O and 0·020 M dicyclohexano-18-crown-6 (DC18C6) in toluene with sorbitan monooleate serving as surfactant. The emulsion was placed into an aqueous source phase solution of the metal nitrates of interest. Of the cations studied, Pb2+was transported most rapidly and selectively. The selectivity of the system for particular cations is governed by the relative Mn+-DC18C6 and Mn+-P2O74−complex stabilities. Formation of a sufficiently stable Mn+-DC18C6 complex is necessary to partition cations into the toluene membrane, and formation of a more stable Mn+-P2O74−complex is necessary to strip cations from the membrane into the receiving phase.

ISSN:0736-6299    

DOI:10.1080/07366298408918459

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The transport of Fe(III) and Co(II) from chloride solutions through a liquid membrane containing as carrier trilaurylammonium chloride dissolved in triethylbenzene and absorbed on a polypropylene microporous support has been studied as function of the stirring speed and of the chemical composition of the system. A previously developed permeation model has been shown to interpret closely the experimental transport data. Conditions for Fe(III)-Co( II) Ni(II) separations have been identified and examples of Fe(III)-Co(II), Fe(III)-Ni(II) and Co(II)-Ni(II) membrane separations have been performed.

ISSN:0736-6299    

DOI:10.1080/07366298408918460

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor