Extraction and separation of U(VI) and Th(IV) from hydrobromic acid media using Cyanex-923 extractant

Abstract

A systematic study of the solvent extraction of uranium(VI) and thorium(IV) from hydrobromic acid media was performed using the neutral phosphine oxide extractant Cyanex-923 in toluene. These metal ions were found to be quantitatively extracted with Cyanex-923 in toluene in the acidity range 5x10-5-1x10-4 M and 5x10-5-5x10-3 M, respectively, and they are stripped from the organic phase with 7.0 M HClO4 and 2.0- 4.0 M HCl, respectively. The effect of the equilibrium period, diluents, diverse ions and stripping agent on the extraction of U(VI) and Th(IV) was studied. The stoichiometry of the extracted species of these metal ions was determined based on the slope analysis method. The extraction reactions proceed by solvation and their probable extracted species found in the organic phase were UO2Br2•2Cyanex-923 and ThBr4•2Cyanex-923. Based on these results, a sequential procedure for their separation from each other was developed

A Survey on Various Methods of Extraction and Recovery of Thorium

“…Higher molar HCl (5 mol/L, 250 °C) appears to be suitable for thorium. As reported by S M Ghag and S D Pawar (84), the separation of Th(IV) and U(VI) from multicomponent mixtures with cyanex ® -923 in toluene with specific concentrations with acid, Th(IV) was found to be 99.3% in a 20 µg sample. U (VI) and Th(IV) were extracted in the acid concentration range 5 x 10 -5 to 1 x 10 -4 M and 5 x 10 -5 to 5 x 10 -3 M respectively.. J C Amaral et al…”

FORMULA ESTABLISHMENT OF COLORLESS Pb(II) COMPLEX WITH N-BENZOYL-N-PHENYL HYDROXYLAMINE (BPA) USING ATOMIC ABSORPTION SPECTROSCOPY

“…After extraction, the loaded organic phase containing high concentrations of Pb(II) may be brought into contact with an acidic solution, whereby the Pb(II) is stripped from the organic phase into the aqueous acidic phase. This phenomenon is called as stripping which is associated with percentage recovery, and the acids used are termed as stripping agents [33][34][35]. Molarity of acid used as a stripping agent in back Table 3.…”