Mass transfer studies in a horizontal pulsed sieve-plate column for uranium extraction by tri-n-octylamine using axial dispersion model

Abstract

In this work, uranium extraction from an aqueous sulfate solution with 0.25M concentration acid, by using 5% v/v tri-n-octylamine (TOA) solvent, 90% v/v kerosene diluent and 5% v/v decanol modifier is studied. The effect of operation parameters (i.e., phase flow rates and pulsation intensity) on the volumetric overall mass transfer coefficients and axial dispersion in a horizontal pulsed sieve-plate column is evaluated using axial dispersion model (ADM). According to the results, increasing pulsation intensity and phase flow rates leads to the enhancement of the mass transfer performance. The continuous phase axial dispersion is found to be significantly higher than that in the dispersed phase. Axial dispersion of a phase is found to be mostly influenced by pulsation intensity and the flow rate of the phase itself and is minor influenced by the second phase flow rate. The overall height of mass transfer unit (HTUoc) is obtained to be less than 0.2 m, indicating high performance of a horizontal pulsed sieve-plate column for solvent extraction of uranium. Furthermore, new correlations are proposed for prediction of Koca, Ec and Ed, which are in satisfactory agreement with the experimental data with AARE values of 1.03%, 3.35% and 1.89% respectively.