Effect of the diluent on the solvent extraction of neodymium(III) by bis(2-ethylhexyl)phosphoric acid (D2EHPA)

Selection criteria of diluents of tri-n-butyl phosphate for recovering neodymium(III) from nitrate solutions

“…The lowest extraction efficiency was observed for the aromatic diluent A 150. Similar trends have been reported for the extraction of rare earths by solvating extractants from nitrate media and by acidic extractants from chloride solutions [27,33]. The extraction efficiency decreased with increasing density, polarity, dielectric constant and Hildebrand solubility parameter value of the diluent in our tested conditions (Table 1) increasing the aromatic content of the diluent as more diluent is incorporated into the extracted species [29].…”

“…Therefore, the positive salting-out effect of nitrate salt is compensating the negative effect of the aromatics content. When varying the concentration of the salting-out agent, neutral extractants were less influenced by the diluent nature than acidic extractants, although the lowest extraction by both TBP and D2EHPA was for the same aromatic diluent A 150 [33].…”

“…In a recent paper, we reported the effect of diluents on the extraction of Nd(III) from aqueous chloride solutions by D2EHPA [33]. The extraction efficiency was found to be largely defined by the aromatic content of the diluent.…”

Recovery of rare earths from the green lamp phosphor LaPO4:Ce3+,Tb3+ (LAP) by dissolution in concentrated methanesulphonic acid

“…An additional advantage of aromatic diluents is that gel formation is suppressed for the extraction of REEs by D2EHPA. 29 In Fig. 2 solvent extraction tests with undiluted D2EHPA are reported for different dilution factors of the concentrated MSA leachate by water before solvent extraction. By selecting a low dilution factor of 10, selective extraction of terbium over cerium/ lanthanum could be achieved.…”

Solvent extraction modeling of Ce/Eu/Y from chloride media using D2EHPA

“…To date, solvent extraction (SX) is the most common technique used for the recovery and separation of REEs using a wide range of extractants, mainly the cationic ones such as bis‐(2,4,4‐trimethylpentyl) phosphinic acid (Cyanex 272, Cy272), di‐(2‐ethylhexyl)phosphoric acid and a mixture of phosphinic and phosphonic acids (Cyanex 572, Cy572) have been reached . Owing to the acidic character of these extractants (Cy272 < Cy572 < D2EHPA), the pH turns out to be one of the most interesting parameters to study because the protons play a crucial role in the extraction mechanism .…”