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Role of the interface in metal solvent extraction kinetics.

Interfacially active reagents are utilized in metal solvent extraction processes and it is therefore important to understand the role of the liquid-liquid interface in the study of the kinetics and equilibria of extraction. The diffusion problems encountered in the traditional apparatus were overcome by using a high speed stirring apparatus. The microporous teflon membrane phase separator permitted more accurate measurements of interfacial areas, characterization of extraction kinetics of metal chelates, and a greater understanding of the phase separation mechanism. In contrast to the neutral ligands, the anionic ligand of dithizones and substituted dithizones showed significant interfacial adsorption at the chloroform/water interface as monitored spectro-photometrically. Equilibrium studies on p-halodithizones indicated that the adsorption constant increased as the substituent was altered from chloro to bromo to iodo, and with the distribution ratio of the ligand. Kinetic studies on dithizone and p-iododithizone with Ni(II) and Zn(II) indicated that the extent of participation of the interface in solvent extraction kinetics of these metal ions is dictated by the interfacial activity of the extractant and the mechanisms of the rate limiting step in the bulk aqueous and interfacial regions.

Identiferoai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/184256
Date January 1987
CreatorsChamupathi, Virittamulla Gamage.
PublisherThe University of Arizona.
Source SetsUniversity of Arizona
LanguageEnglish
Detected LanguageEnglish
Typetext, Dissertation-Reproduction (electronic)
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.

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