Abstract

The application of a mathematical model for copper permeation through a hollow fiber-type supported liquid membrane containing a salicylaldoxime (LIX-860) as the carrier was studied at 30°C. The liquid membrane (the carrier in n-hexane) permitted an adequate copper diffusion when the pH of mine water was adjusted around a value of 2.0. A quantitative analysis of the experimentally observed results is given. A discrete formulation was obtained through the application of the Crank-Nicholson method to a set of dimensionless differential equations, used to model the metal concentration drop along the fiber tube under certain boundary conditions. The model developed in this study considers a chemical reaction between the metal and the oximic carrier at the aqueous feed/membrane interphase. The application of a numerical model to evaluate the permeation of metal along the hollow fiber membrane is presented. In the model, the kinetic equations for extraction and stripping steps deduced in previous studies were introduced. A fairly close agreement was obtained between the dimensionless average concentration of metal along the dimensionless axial distance of the fiber, calculated according to the model and the experimentally observed values. This fact was appreciated in runs carried out using an extractor with a variable number of fibers inside. It was found that the metal concentration drops in a similar way in all experiments. © 2002 Elsevier Science B.V. All rights reserved.