摘要:

The linear polyether, l,13-bis-[;8-quinolyl)-l,4,7,10,13-pentaoxatridecane (K-5), has been shown to enhance the extraction of Am(III), Cm(III), and Eu(III) by thenoyltrifluoroacetone (HTTA). The extraction of the trivalent metals from an aqueous acetate buffer system (pH =4·8) into HTTA/chloroform at 25°C was studied as a function of the concentration of K-5 in the organic phase. The synergistic specie was determined to be M(TTA)3K-5 and organic phase stability constants for the formation of this complex were evaluated. The results of this study indicate that K-5 has the ability to show some size selectivity for the trivalent metal ion.

ISSN:0736-6299    

DOI:10.1080/07366298308918399

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The extraction of zirconium(IV) from aqueous solutions of hydrochloric, nitric and sulphuric acids by trioctylphosphine oxide (TOPO) in kerosene has been investigated under different conditions. The organic phases have been studied by infrared and nuclear magnetic resonance spectroscopies. The extraction equilibria are discussed in light of the results obtained.

ISSN:0736-6299    

DOI:10.1080/07366298308918400

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Extraction of lanthanides and yttrium was studied in the interval of ammonium nitrate concentrations from 1 to 10M, and of Adogen-464 nitrate concentrations from 0·00039 to 0·39M. From the aqueous phase separation factor and from the published stability constant for Eu, stability constants for 1:1 complexes of La, Nd, Gd, Ho, Tm, Lu and Y have been determined, at 1M ammonium nitrate concentration. It was found that stability constant decreases from 2·7 for La to 2·3 for Lu. It has been shown that in the interval of Adogen-464 nitrate concentrations employed, lanthanides from La to Nd appear in the organic phase as 1:5 complexes, whereas lanthanides heavier than Nd appear also as 1:4 complexes. Relative values (with regard to lanthanum) of Gibbs energy, enthalpy (from the temperature effect) and entropy for formation of 1:5 complexes,and the position of yttrium within lanthanides have been determined. It is concluded from the experimental data that the extracted 1:4 and 1:5 complexes are of the inner sphere type, with nitrate ions acting as bidentate ligands, and that the contribution from covalency to bonding is the same in the aquo ion and in the 1:5 nitrato complex.

ISSN:0736-6299    

DOI:10.1080/07366298308918401

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Extraction systems containing diisopropyl ether (IPE) are interesting due to some of their characteristics such as the formation of a third liquid phase (heavy organic phase) or extraction enhancement under given conditions

ISSN:0736-6299    

DOI:10.1080/07366298308918402

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The extraction of HNO3from aqueous solutions by permeation through a number of supported liquid membranes containing basic carriers dissolved in diethyl benzene has been studied. The results have shown that the best permeations are obtained with long chain aliphatic amines (TLA, Primene JM-TTM) followed by TOPO and then by other monofunctional and bifunctional organophosphorous basic carriers. The influence of an aliphatic diluent on the permeability of HNO3through a supported liquid membrane containing TLA as carrier was also investigated. In this case the permeability to HNO3 decreases as a result of the lower diffusion coefficient of the acid-carrier complex in the more viscous aliphatic solvent.

ISSN:0736-6299    

DOI:10.1080/07366298308918403

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The extraction experiments of copper from aqueous solutions of copper sulfate by LIX65N-kerosene solutions were carried out at 25°C in liquid-liquid dispersions. Both reaction rates of the forward and backward extractions were obtained in a stirred vessel, being combined with the equilibrium data. For a multistage column in continuous operation, the holdup data of the dispersed organic phase were correlated with the stirring speed, flow rates and LIX65N concentration. It was found that the extracted fraction of copper in the multi-stage column can be predicted from a stage-to-stage calculation using the extraction kinetics and the holdup obtained in the present work.

ISSN:0736-6299    

DOI:10.1080/07366298308918404

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The method of slope analysis has been used to analyze cobalt extraction by dlnonylnapthalene sulfonic acid (HDNNS) in hexane/ aqueous nitrate systems in the absence and presence of 0·01 mol dm-35,8-diethy1-7-hydroxy-6-dodecanone oxime (H2Ox; the active extractant in the commercial reagent, LLX63, a product of Henkel Corp.). In the absence of H2Ox, cobalt is extracted by HDNNS micelles and the log D versus log [HDNNS] plot gives a slope of unity. In the presence of 0·01 mol-dm-3H2Ox, the corresponding plot shows a maximum at 5·6×l0-3mol dm-3HDNNS and a minimum at 3×l0-2mol dm-3HDNNS. At low HDNNS concentrations (≤ 5·6×l0-3mol dm-3), the log D versus log [HDNNS] plot has a slope of 1·0 while at high HDNNS concentrations (≥ 3×l0-2mol dm-3) Cobalt distribution approaches that of the HDNNS-alone system. The HDNNS behavior in the presence of H2OX is explained in terms of the presence of a mixed oxime-sulfonate micelle whose concentration goes through a maximum as HDNNS concentration Is increased. The pH dependence of log D expected from the slope analysis (i.e. a slope of 2·0 for a log D vs pH plot) is masked by the presence of an H+/K+cation exchange between HDNNS and the aqueous KNO3., supporting electrolyte.

ISSN:0736-6299    

DOI:10.1080/07366298308918405

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The synergism of trivalent actinides and lanthanides has been reviewed oritically. Different systems Including β-di-ketones and several other chelating agents with various neutral donors have been discussed. The thermodynamic parameters, effect of diluents, auto-synergism and synergism with eutectic mixtures have been discussed In the case of trivalent actinides and lanthanides. Also the mechanism of synergism and the various possible uses of this phenomenon have been referred to with the possible data available.

ISSN:0736-6299    

DOI:10.1080/07366298308918406

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0736-6299    

DOI:10.1080/07366298308918407

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor