Start
May 12, 2017 - 16:00
End
May 12, 2017 - 17:00
Venue
Room. No. 130 Chemical Engg. Dept.
Event Type
Speaker
Dr. Meena Singh (PhD from ICT Mumbai)
Title
Molecular dynamic simulations in Extraction and Separation Processes of Metal ions
Abstract: Extraction of metal ions from spent nuclear fuel or other industrial waste streams is usually done by trialkyl phosphates alkylated phosphoric acid or phosphine oxides under varying conditions of pH and concentration. Molecular dynamics provides a tool to understand the extraction process better at molecular level and can also help in design of a specific extractant for a given species. The solution behavior of N N N’ N’-tetraoctyl diglycolamide (TODGA) di-2-ethylhexyl phosphoric acid (DEHPA) and tetrabutyl phosphate (TBP) the commonly used extractants for metal ions is simulated in non-aqueous conditions. These extractants form reverse micellar aggregates along with mineral acid and water molecules in the non-aqueous solutions. These self-aggregates are dispersed in the organic dodecane phase or form well defined reverse micelles grown sufficient in size depending on the acid concentration. At sufficiently high concentration of the acid the formation of a third phase is also seen with TBP. MD simulations can predict the extent of extraction of Cadmium Neodymium Strontium Zinc and Lead by TODGA and TBP into dodecane. The simulated values of diffusion coefficient and coordination numbers of various species are in good agreement with the experimental values. The existence of a variety of species in solutions can explain effect of operating parameters on the extraction processes.