摘要:

The mass transfer rate of Zn(II), Co(II) and Ni(II) between aqueous nitrate solutions and n-dodecane solutions of the organic soluble ligand HDEHP has been investigated using a forced convection, constant interfacial area stirred cell. The distribution ratios necessary to evaluate the kinetic experiments have been determined and the equilibrium constants which describe the heterogeneous complex formation reaction between Zn2+, Co2+, Ni2+and HDEHP have been evaluated. The results have been interpreted according to two limiting models: 1) the mass transfer rate is controlled by slow reversible interfacial reactions, 2) the mass transfer is controlled by interfacial film diffusion. Both models are adequate to Interpret the experimental data. The conclusion Is reached that, if interfacial chemical reactions are rate controlling, rate constants of interfacial complex formation reactions independent of the nature of the cation are obtained. This result supports a reaction mechanism which is rate controlled by the microscopic diffusion of the cation through a viscous and structured layer of interfacial water adjacent to the liquid interface

ISSN:0736-6299    

DOI:10.1080/07366298308918390

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The extraction behavior of Zr from aqueous HNO3was studied using dihexyl N, N-diethylcarbamoylmethylphosphonate (DHDECMP). Distribution ratios were examined as a function of contact time, concentration of solute, acid, and extractant and extraction temperature. It was found that the extractant dependency for Zr is second power. Temperature dependency studies were hindered by an apparent Zr specie change above 30°C. Extraction of Zr is strongly NO3dependent

ISSN:0736-6299    

DOI:10.1080/07366298308918391

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Experimental data for the distribution of uranyl nitrate and water between an aqueous phase and an organic phase containing 5-100 vol % trlbutyl phosphate (TBP) in an odorless kerosene-like diluent (Amsco 125-82) have been reexamined by considering alternative models in which competitive equilibria involving water and uranyl nitrate are assumed. These models are compared and contrasted with earlier analyses which assumed the existence of only a single extractive equilibrium in the two-phase system. Although the new models are not quite as accurate as the earlier model for uranium extraction, they contain fewer adjustable parameters, are mathematically simpler, and can be used to help predict the extraction of water as well as uranyl nitrate

ISSN:0736-6299    

DOI:10.1080/07366298308918392

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

An equilibrium study of the Na+-K+-H+exchange on crystalline α-zirconium phosphate has been carried out. Isotherms for the Ion exchange have been determined and phases formed during the exchange have been identified.

ISSN:0736-6299    

DOI:10.1080/07366298308918393

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A tin(IV) antimonate(SnSbA) cation exchanger has been synthesized under different conditions; changes in the concentration, the molar ratio of Sb/Sn in the starting solution, and hydrolysis temperature. The products obtained were characterized by powdered X-ray diffraction and thermal analysis, and infrared spectra. The pH titration curves on SnSbA showed apparently mono-basic acid, but can be expected to the presence of the number of the functional groups with overlapping different pKa values. The increased acidities were observed with increasing the molar ratio (Sb/Sn) in the exchanger. The equilibrium distribution coefficients were determined at micro-amount of alkali metal ions in the hydrochloric acid solution. The SnSbA showed an unusual selectivity for alkali metal ions compared to cation exchange resins and other inorganic ion-exchangers.

ISSN:0736-6299    

DOI:10.1080/07366298308918394

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Several different liquid distributors were manufactured and separately attached to the top of a large-sized, 50 cm i. d. ion exchange column. Effective dispersion coefficients of these distributors were measured by the stepwise response method, and were compared with those of smaller-sized columns. It was found that the use of an appropriate distributor enables one to scale up the column size without reducing the separation performance

ISSN:0736-6299    

DOI:10.1080/07366298308918395

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The chemistry of the mixed solvent extractants, dibutyl-N, N-diethylcarbamoylmethylphosphonate (DBDECMP)-tri -£-butyl phosphate (TBP), using carbon tetrachloride diluent, was studied for extracting americium (III) from nitric acid at various concentrations and temperatures. Synergistic extraction of americium was observed and an extraction mechanism is proposed based on slope analysis, infrared studies, and temperature variation studies. Similar studies were performed with dibutyl-N, N-diethylcarbamoylphosphonate (DBDECP)

ISSN:0736-6299    

DOI:10.1080/07366298308918396

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A review on the studies of solvent extraction of zirconium and hafnium, either individually or together from other associated elements, using various solvents has been presented.

ISSN:0736-6299    

DOI:10.1080/07366298308918397

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0736-6299    

DOI:10.1080/07366298308918398

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0736-6299    

DOI:10.1080/07366298308918387

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor