Kinetics And Mechanism Of Zinc Extraction From Sulfate Medium With Di(2-Ethylhexyl) Phosphoric Acid

Abstract

Kinetic studies of the extraction of zinc from aqueous sulfate solution by di(2-ethylhexyl) phosphoric acid in kerosene were made, using a constant interfacial area cell. Measurements of the extraction and stripping rates led to the identification of rate expressions and a suggested mechanism of this reaction. Based on the nature of the extractant and the reaction mechanism for the formation of zinc complex in the aqueous phase, a simple extraction scheme is proposed in which the rate-controlling step is interfacial. The mass-action constant obtained in the present kinetic study is considered to agree with the extraction constant obtained in the previous equilibrium study. Effects of the total sulfate concentration in the aqueous phase on the extraction and stripping rates were also investigated. © 1986, The Society of Chemical Engineers, Japan. All rights reserved.