Modeling of the Solvent Extraction Equilibrium of Uranium (VI) Sulfate with Alamine 336

Abstract

The present study investigated the solvent extraction of uranium from sulfate acid solutions using Alamine 336 as an extractant dissolved in commercial kerosene Exxsol D-100 and 5% v/v of tridecanol as a modifying agent at room temperature (25±2) ºC and an aqueous/organic volumetric ratio of unity. Experiments were carried out at typical concentration levels like those used at the uranium plant of INB (Indústrias Nucleares do Brasil), Brazil. Data fitting using the slope analysis method revealed that uranium is extracted by Alamine 336 as UO2SO4 and UO2(SO4)2 2- species, forming (R3NH+)2UO2(SO4)2 2- in the organic phase; the extraction of the species UO2(SO4)3 4- seems improbable for the operating conditions investigated. The extraction of uranium is significantly reduced when the concentrations of sulfate and chloride ions in the aqueous phase are increased.