Studies on solvent extraction of La(III) using [A336][NO₃^–] and modeling by statistical analysis and neural network

Understanding the Recovery of Rare-Earth Elements by Ammonium Salts

“…Maximum recoveries of La (100%), Nd (98%), and Dy (92%) were obtained at 1.00 M IL with an expected gradual decrease in percentage recovery observed as the concentration of IL (M) decreased [14,15]. When IL concentration was constant (0.1 M) and NaNO3 salt varied (1-7 M), the REE transportation into the organic phase increased substantially as NaNO3 salt concentration increased (Figure 1), in line with previous work [3,4]. For La, Nd, and Dy minimal recovery (<5%) was obtained at 1 M NaNO3, whereas at 7 M NaNO3, 99% La, 85% Nd, and 52% Dy were recovered.…”

“…It is seen that IL is naturally hydrophilic, solubilizing a proportional amount of water in relation to its concentration. FT-IR studies have shown that ILs of ammonium cations readily extract water, indicated by the presence of a strong broad stretch at ~3450 cm −1 following contact with water [3,4,47,57]. The water content seen for the metal-loaded IL phase is comparable, albeit slightly lower than that seen for the water-only contact, indicating that rare-earth extraction is not dependent on the extraction of water and that a reverse-micelle mechanism of extraction is unlikely.…”

“…Using the optimized conditions of 0.01 M IL and 7 M NaNO3, it was found that the transport of La from the aqueous to the organic phase by IL is rapid (Figure 3), as seen in similar studies [3,47,48]; after only 60 s the concentration of La in the organic phase is maximized. The back-extraction of the REEs from the IL organic phase into a fresh aqueous solution was studied and shows that complete back-extraction is achieved using water ( Figure S2) [3,4,47], in contrast to pH swing reagents such as D2EHPA that typically require acidic strip conditions [42,43,49,50]. Some selectivity in the back-extraction process is achieved through the addition of NaNO3 to the aqueous phase.…”

“…Ionic liquids (ILs) are particularly desirable as reagents and solvents due to their ability to be tailored through the modification of their cation and anion components, and their perception as having "green credentials" due to their negligible vapor pressure, high thermal stability, and non-flammability [1]. They are often immiscible with aqueous phases, and this feature, combined with their other properties, has been exploited in the separation and recovery of metals such as the rare earth elements (REEs) by solvent extraction [2][3][4][5][6][7][8]. The use of ILs in solvent extraction processes can minimize extractant loss, reduce environmental contamination, and limit the use of volatile organics as diluents [3,9].…”

Experimental Study and Artificial Intelligence Modeling of Dye Removal in Microfluidic Systems

“…The authors have declared no conflict of interest. Extraction of mercaptan from naphtha Extraction percentage modeling by ANN 0.9862 [31] Lanthanum extraction from acidic nitrate Extraction percentage prediction by ANN 0.999 [32] Extraction of phenol compounds Modeling of the extraction process by ANFIS 0.997 [33] Extraction of mercaptan from naphtha Extraction percentage prediction by RSM 0.9798 [31] Calcium extraction from the aqueous phase Extraction yield modeling by RSM 0.9830 [34] Copper extraction from an aqueous solution Extraction percentage modeling by RSM 0.985 [35]…”