Solvent Extraction of La(III) from Chloride Medium in the Presence of Two Water Soluble Complexing Agents with di-(2-ethylhexyl) Phosphoric Acid

Size Selective Ligand Tug of War Strategy to Separate Rare Earth Elements

Separating rare earth elements is a daunting task due to their similar properties. We report a "tug of war" strategy that employs a lipophilic and hydrophilic ligand with contrasting selectivity, resulting in a magnified separation of target rare earth elements. Specifically, a novel water-soluble bis-lactam-1,10-phenanthroline with an affinity for light lanthanides is coupled with oil-soluble diglycolamide that selectively binds heavy lanthanides. This two-ligand strategy yields a quantitative separation of the lightest (e.g., La-Nd) and heaviest (e.g., Ho-Lu) lanthanides, enabling efficient separation of neighboring lanthanides in-between (e.g., Sm-Dy).

Colloidal Model for the Prediction of the Extraction of Rare Earths Assisted by the Acidic Extractant

We propose the statistical thermodynamic model for the prediction of the liquid-liquid extraction efficiency in the case of rare-earth metal cations using the common bis(2-ethyl-hexyl)phosphoric acid (HDEHP) extractant. In this soft matter-based approach, the solutes are modeled as colloids. The leading terms in free-energy representation account for: the complexation, the formation of a highly curved extractant film, lateral interactions between the different extractant head groups in the film, configurational entropy of ions and water molecules, the dimerization, and the acidity of the HDEHP extractant. We provided a full framework for the multicomponent study of extraction systems. By taking into account these different contributions, we are able to establish the relation between the extraction and general complexation at any pH in the system. This further allowed us to rationalize the well-defined optimum in the extraction engineering design. Calculations show that there are multiple extraction regimes even in the case of lanthanide/acid system only. Each of these regimes is controlled by the formation of different species in the solvent phase, ranging from multiple metal cation-filled aggregates (at the low acid concentrations in the aqueous phase), to the pure acid-filled aggregates (at the high acid concentrations in the aqueous phase). These results are contrary to a long-standing opinion that liquid-liquid extraction can be modeled with only a few species. Therefore, a traditional multiple equilibria approach is abandoned in favor of polydisperse spherical aggregate formations, which are in dynamic equilibrium.

Solvent Extraction and Separation of Nd, Pr and Dy from Leach Liquor of Waste NdFeB Magnet Using the Nitrate Form of Mextral® 336At in the Presence of Aquo-Complexing Agent EDTA

：Solvent extraction and separation of Pr, Nd and Dy from a synthetic leach solution of spent NdFeB magnet from wind turbines in the presence of aquo-complexing agent Ethylenediaminetetraacetic acid (EDTA) was studied using the nitrate form of Mextral® 336At ([336At][NO3]) as an extractant. The effect of different process parameters such as pH, extractant, nitrate, and EDTA concentrations on the extraction of Pr, Nd and Dy was studied. The extraction of these rare earths elements follows the order Pr > Nd > Dy, whereas EDTA forms stable complexes in the order Dy > Nd > Pr. The synergy of these two effects improved the selectivity among these elements as compared to when no aquo-complexing agent was used. The mechanism of extraction of rare earth elements was established by slope analysis method. The Fourier-Transform Infrared Spectroscopy (FTIR) spectra of [336At][NO3] and extracted Nd complex were recorded to understand the interaction of extractant with rare earth metal ions in the organic phase.

Sulfonylcalix[4]arene functionalized nanofiber membranes for effective removal and selective fluorescence recognition of terbium(iii) ions

A novel sulfonylcalix[4]arene functionalized aminated polyacrylonitrile (APAN) nanofiber membrane was fabricated, exhibiting good Tb³⁺ adsorption capacity and photoluminescence performance.

Separation of rare earths and other valuable metals from deep-eutectic solvents: a new alternative for the recycling of used NdFeB magnets

Neodymium and dysprosium can be separated using a new extraction system based on a deep-eutectic solvent and Cyanex® 923 diluted in toluene.

Separation of rare-earth ions from ethylene glycol (+LiCl) solutions by non-aqueous solvent extraction with Cyanex 923

Mixtures of rare earths are separation by non-aqueous solvent extraction with two immiscible organic phases.

Study on the aqueous solution behavior and extraction mechanism of Nd(iii) in the presence of the complexing agent lactic acid with di-(2-ethylhexyl) phosphoric acid

The aqueous solution behavior and extraction mechanism of single Nd(iii) from a chloride medium with di-(2-ethylhexyl) phosphoric acid (D2EHPA, H₂A₂) in the presence of the complexing agent lactic acid (HLac) have been reported.

The kinetics and mechanism of solvent extraction of Pr(iii) from chloride medium in the presence of two complexing agents with di-(2-ethylhexyl) phosphoric acid

The extraction kinetics of Pr(iii) from chloride medium containing two complexing agents lactic acid (HLac) and citric acid (H₃cit) with di-(2-ethylhexyl)phosphoric acid (D2EHPA, H₂A₂) have been investigated by constant interfacial area cell with lamina flow.