Chemical Engineering Research & Design, Vol.125, 181-189, 2017
Equilibrium and kinetics of uranium(VI) extraction from a sulfate leach liquor solution by Alamine 336 using single drop technique
The equilibrium extraction of U(VI) from a sulfate leach liquor was studied using Alamine 336 in kerosene. The effects of operating parameters and temperature were investigated on the extraction process. On the basis of the slope analysis data, the composition of the extracted species was [UO22+] with the extraction equilibrium constant (log K-eq) = (2.79 +/- 0.05). The influence of the temperature on the value of the equilibrium extraction constant indicated an exothermic and spontaneous extraction. In this work for the first time, the kinetic parameters of U(VI) extraction from sulfate solution was measured by the single drop technique. The effects of the main parameters such as column height, nozzle diameter, temperature, aqueous phase pH, extractant, uranium and sulfate concentrations were separately studied on the extraction rate. The results showed that the uranium extraction rate was mainly controlled by diffusion mechanism and the chemical reaction occurred at the interface of the two phases. The forward extraction rate was obtained as follows: R-U (kmol/m(2)s) =2.65 x 10(-5) [UO22+](1.5) [R3N)(0.5) [SO42-](-0.5) [H+](-0.2) (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Keywords:Uranium(VI);Extraction;Alamine 336;Sulfate leach liquor;Single drop technique;Kinetic of reaction