Effect of hydrophobicity of extractant on extraction kinetics of copper with N-8-quinolylsulfonamide.

Abstract

Using four kinds of alkylbenzene-substituted N-8-quinolylsulfonamides of different alkyl-chain length and their copper chelate complexes, kinetic studies concerning the extraction of copper with extractant and the stripping of copper with sulfuric acid were carried out in a membrane extractor using a hollow fiber. It was found that the interfacial reaction between the adsorbed copper complex (CuR+ad) and the adsorbed extractant (HRad) is a rate-controlling step among the interfacial reaction steps of the extraction and stripping processes, regardless of the alkyl-chain length of the extractants, and that the reaction rate constant of the ratecontrolling step is proportional to the equilibrium constant of this reaction for each of the four kinds of extractants. The validity of a diffusion model with the interfacial reaction was confirmed by agreement of the observed extents of copper extracted and stripped with those calculated over a wide range of experimental conditions.