Stripping and recycling of metal ions in aqueous nitric acid solutions: Experimental and molecular dynamics insights

摘要

Stripping of metal ions (i.e., Cs+ and Na+) in presence of ionophore such as dibenzo-18-crown-6, (DB18C6) from the ionic liquid phase to the aqueous nitric acid phase by molecular dynamics simulation is reported. The experimentally determined stripping percentages of Na+ (i.e., 43.4, 38.5, 34.4, and 31.9%) were found to be higher than the same for Cs+ (i.e., 32.6, 32.0, 31.3, and 30.2%). The nonbonded and the hydrogen bond energies between Na+ and water (i.e., -356.41 and -363.77 kcal/mol) were higher when compared with Cs+ (i.e., -212.43 and -221.04 kcal/mol). The spatial distribution functions further confirmed that the surfaces of Na+ were very closely distributed around the active sides of water whereas for Cs+, it was distributed very far from the water molecules. In the penultimate section, the effect of methanol to the aqueous phase was studied so as to enhance the extraction efficiency of the complex.