Extraction equilibria of copper and zinc with alkylphosphonic acid monoester

Abstract

Measurements of the extraction equilibria of copper and zinc with 2-ethylhexyI phosphonic acid mono-2-ethylhexyl ester dissolved in n-heptane or toluene diluent were carried out at 303 K. It was found that the extractant (HR) is apt to dimerize in n-heptane diluent. It was clarified that copper and zinc are extracted according to the following equations, respectively, in the low concentration range of the metals. [formula omitted] Extraction equilibrium constants, Ke,Cu = 1.0 × 10−4 and Ke,Zn = 2.5 × 10−2 mol1/2/dm3/2 were obtained. From the above experimental results, it is seen that selective separation of copper and zinc is possible by solvent extraction with the extractant used in this study. © 1982, The Society of Chemical Engineers, Japan. All rights reserved.