| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 640149 | Separation and Purification Technology | 2016 | 7 Pages |
•First time evaluation of diluent behavior of [N1888][NTf2] for Pu(IV) extraction.•Efficient extraction of Pu(IV) by ionic liquid alone.•Mechanistic pathway is different as compared to imidazolium ionic liquid diluents.•Easy stripping from ionic liquid phase by dilute nitric acid.
The extraction behavior of plutonium(IV) was studied in the room temperature ionic liquid, trioctylmethylammonium bis(trifluoromethanesulfonyl)imide ([N1888][NTf2]) containing a monoamide, N,N-dihexyloctanamide (DHOA). The unusual extraction of Pu(IV) observed in this ionic liquid system was reported in this paper. The extraction behavior of plutonium(IV) was investigated as a function of various parameters, such as feed acid concentration, extractant and ionic liquid concentration, type of the extractants, equilibration time and temperature. Changing the extractant from DHOA to tri-n-butyl phosphate reduced the distribution ratio of Pu(IV). The extraction trend of Pu(IV) in neat [N1888][NTf2] was compared with those observed in other ionic liquids such as 1-alkyl-3-methylimidazolium bistriflimide ([Cnmim][NTf2]). Pu(IV) extraction in [N1888][NTf2] was found to follow a combination of anion exchange mechanism and neutral solvation pathway at feed acidities above 2 M HNO3. The extraction of Pu(IV) in DHOA/[N1888][NTf2] was also compared with those observed in a molecular diluent system, DHOA/n-DD. All thermodynamic parameters governing the extraction of plutonium(IV) in [N1888][NTf2] was determined and discussed in detail. Stripping of Pu(IV) from the loaded ionic liquid phase was performed using dilute nitric acid.
