Reaction Of Nd Research Articles

A cleaner and sustainable method for recovering rare earth and cobalt from NdFeB leaching residues

NdFeB leaching residues (NLRs) is produced by the treatment of NdFeB waste by HCl preferential dissolution method, which contains about 1% rare earth and cobalt (Co). The extraction of valuable elements from the residue has a great impact on the sustainable utilization of rare-earth resources. In this study, a high-efficiency hydrometallurgy process was proposed to achieve a high conversion of valuable elements and the recycling of additives by reductive acid leaching. First, NLRs were characterized by the Bgrimm process mineralogy analyzing system, which confirmed that the iron oxide main phase encapsulates the rare earth phase. It was effective in destroying the main phase by chemical dissociation. In addition, the effects of temperature, reaction time, initial acid concentration, solid-liquid ratio (S/L), and reducing agent dosage on leaching efficiency were investigated. Under optimal conditions, 90.6% Co, 89.1% neodymium (Nd), 77.2% praseodymium (Pr), 88.7% cerium (Ce) and 83.8% iron (Fe) leached. The reaction mechanism and leaching kinetics in the leaching process were systematically explored. The kinetic analysis indicated the leaching reaction of Co and Fe was controlled by interfacial chemical reaction and the leaching reaction of Nd, Pr and Ce was controlled by internal diffusion. The activation energies of Co, Fe, Nd, Pr and Ce were 21.06, 18.07, 23.37, 20.56 and 18.52 kJ/mol. Furthermore, the reducing agent (copper powder) was successfully recovered by iron powder. The recovery rate of the copper powder was 99.93% and the purity was 93.42%. The proposed process has a promising application for industrial-scale recycling.

Comparative Spectrophotometric Determination of Neodymium (III), Praseodymium (III), Samarium (III) and Terbium (III) in Aqueous and Micelle Media

This research work titled comparative spectrophotometric determination of neodymium (III), praseodymium (III), samarium (III) and terbium (III)in aqueous and micelle media using schiff base was carried out with the aim to use a simple, rapid and sensitive spectrophotometric method for the determination of Nd (III), Pr (III), Sm(III) and Tb(III) using the Schiff base 2,2′-((1E,1′E)-(1,2-phenylenebis(azanlylidene)bis (methanylylidene))diphenol (BSOPD) as a ligand. Spectral and absorbance measurements were carried out using UV/Visible Spectrophotometer (Jenway model no.: 6305) with 1-cm matched quartz cells. This method of experiment was based on the formation of green coloured complexes, upon the reaction of Nd(III) and Pr(III) and a brown coloured complexes for Sm(III) and Tb(III) having a maximum absorbance of 376, 386, 384 and 380 nm respectively. The comparative analysis of the complexes formed in aqueous and in micellar media were investigated in this study. In the obtained results, it was discovered that, Beer’s law was obeyed in the concentration ranges of 0.001 - 0.02 ppm. The molar absorptivity was found to be in the range of 7,776- 23,197 and 27,087 dm³mol^-1cm^-1 and the Sandell’s sensitivity for the compounds analyzed were in the ranges of 6.13-19.34 g cm^-2. The increase in absorbance in the presence of the surfactants is due to micelle formation. The reactants were bound in a small volume of stern layer of the micelle leading to a greater increase in concentration effect. This effect in concentration reaches a maximum before decreasing due to dilution effect occasioned by increase in metal ion concentration.

Collision of C2 with NH and deuterated analogs in the interstellar medium. Scattering calculations

ABSTRACT Shephard’s interpolation potential energy surface and isotopic substitution were used to understand the mechanisms of chemical reactions; the NH + C2 reaction potential energy surface was constructed in this research and evaluated using ab-initio calculations. Classical trajectory simulations were used to calculate the reaction probability and cross-section. In addition, the rate constant by the nonlinear least-squares fitting was calculated. These were determined as a function of cross-section. In non-reactive trajectories for inelastic collisions, the scattering angle was estimated. The effects of the impact parameter and the relative velocity of particles on the reaction probability, transmitted energy, and dispersion angle were investigated. In addition, Isotopic substitution in the NH radical was evaluated for the effect of the mass of the target and incident particles on the cross-section, reaction probability, dispersion angle, and reaction rate. To calculate the kinetic isotope effect, the influence of the mass of colliding molecules on the observable properties was studied. Deuterated imidogen reacted faster than hydrogenated imidogen. These observations provided valuable insights into the details of the mechanisms, possible reactions of ND and NH + C2 , and deuterium fractionation.

Electrochemical extraction mechanism of Nd on Ga-Al alloy electrode

In order to reveal the extraction mechanism of Nd on Ga-Al alloy electrode, the electrode reactions and alloy formation between Nd(III), Ga(III) and Al(III) ions in different molten salt systems were studied by multiple electrochemical methods. The cyclic voltammetry curves measured in melts with different concentrations confirmed that only three intermetallic compounds were formed in both Ga-Nd and Al-Nd systems. The preferential interaction of Nd with Ga in Ga-Al-Nd ternary system was further verified by cyclic voltammetry curves with varying potential window. In particular, the co-reduction process of three ions was gradually determined by the comparison of electrochemical behaviour in different melts. In addition, the interfacial reaction of Nd(III) ion on liquid Ga-Al alloy cathode was investigated, and the corresponding exchange current densities were measured through galvanostatic pulse (0.0049, 0.0047, 0.0056 and 0.0055 A cm−2) and Tafel method (0.0029 A cm−2).

Gas-Phase Reactivity of Ozone with Lanthanide Ions (Sm+, Nd+) and Their Higher Oxides

The kinetics of SmOn+ (n = 0-2) and NdOn+ (n = 0-2) with O3 are measured using a selected-ion flow tube. Reaction of Nd+ to yield NdO+ + O2 occurs rapidly, with a rate constant near the capture-controlled limit of ∼8 × 10-10 cm3 s-1. NdO+ reacts at ∼40% of the capture limit to yield NdO2+ with little temperature dependence from 200 to 400 K. NdO2+ likely reacts very slowly (k ∼ 10-13 cm3 s-1) to yield NdO+ + 2O2, does not react to yield NdO3+, and associates slowly (k ∼ 10-12 cm3 s-1) to yield NdO2+(O3)1-3. Reaction of Sm+ also yields SmO+ at near the capture limit at all temperatures, but a significant fraction (∼50%) of the SmO+ is produced in excited states that are long-lived compared to the millisecond time scale of the experiment. These states are evidently resistant to both radiative and collisional relaxation. The excited-state production is likely due to a spin-conservation constraint on the reaction, despite the large spin-orbit coupling typical for lanthanide-containing species. Ground-state SmO+ reacts inefficiently (k = 2 × 10-11 (T/300)-2.5 cm3 s-1) to yield SmO2+ + O2, while the excited-state SmO+* reacts at the capture limit, with branching to yield Sm+ + 2O2 (ΔHr,0K = 148.7 ± 0.4 kJ mol-1 for ground-state SmO+) approximately 60% of the time, the remainder forming SmO2+, which further reacts with O3 to yield SmO+ at about 1% of the collisional value.

Activation of D2 by Neodymium Cation (Nd+): Bond Energy of NdH+ and Mechanistic Insights through Experimental and Theoretical Studies.

The kinetic-energy-dependent cross section for the reaction of Nd+ with D2 was studied by using a guided ion beam tandem mass spectrometer. The formation of NdD+ is endothermic, and analysis of the reaction cross section gave an NdH+ 0 K bond dissociation energy (BDE) of 1.99 ± 0.06 eV. Theoretical calculations for the NdH+ BDE were performed for comparison with the experimental thermochemistry and generally gave accurate results. Additionally, relaxed potential energy surfaces for NdH2+ were performed, and no strongly bound dihydride intermediate was located. The Nd+ + D2 reactivity and BDE of NdH+ are compared with analogous results for the lanthanide cations La+, Ce+, Pr+, Sm+, Gd+, and Lu+ to establish periodic trends and insight into the role of the electronic configurations on this reactivity and the lanthanide hydride cation bond strengths.

The effects of the vibrational excitation on H + ND(a1Δ, j0 = 2, v0 = 0,1,2) reaction

Reactions of vibrationally excited ND (a1Δ, j0 = 2, v0 = 0,1,2) molecule with H atom have been carried out on the modified NH2 potential energy surface (PES) for the 2A′ excited state using Centrifugal Sudden approximation. The chemical reaction of ND (a1Δ) with H can proceed via the depletion ND + H → N + HD and the exchange pathways ND + H → NH + D. So, we present the time-dependent wave packet quantum scattering calculations of initial-state-resolved reaction probabilities, integral cross sections and initial state-selected reaction rate constants for exchange and depletion channels of the title reaction. For exchange reaction, it was found that vibrational excitation plays a very important role in the integral cross sections and rate constants.

Investigation of electrodeposition behavior for Nd(III) in [P2225][TFSA] ionic liquid by EQCM methods with elevated temperatures

The electrodeposition behavior of Nd(III) in an ionic liquid, triethyl-pentyl-phosphonium bis(trifluoromethyl-sulfonyl) amide ([P2225][TFSA]), was investigated on an electrochemical quartz crystal microbalance (EQCM) at elevated temperatures. Cyclic voltammetry with EQCM measurements of Nd(III) in [P2225][TFSA] at 363, 373 and 378K were performed. A clear cathodic peak with increasing mass and decreasing ηρ (where η is the viscosity and ρ is the density) was observed at −2.79V. Considering the results of our previous investigations, this peak indicated the reduction of Nd(III) to Nd(0) as [Nd(III)(TFSA)5]2−+3e−→Nd(0) + 5[TFSA]−. In addition, the apparent molar mass, Mapp, between −2.49 and −2.94V calculated from the mass change was 140.4gmol−1, which was close to the theoretical value for the electrodeposition reaction of Nd(III)/Nd(0), 144.2gmol−1.Moreover, controlled potential electrolysis with EQCM (CPE/EQCM) measurements at −3.20V was performed for 0.05 and 0.10M Nd(III) in [P2225][TFSA] at 373K. The calculated Mapp values in 0.05 and 0.10M Nd(III) in the initial stage of CPE/EQCM analysis were 147.3 and 148.8gmol−1, respectively, which were close to the theoretical value for reduction of Nd(III) to Nd(0), 144.2gmol−1; thus, electrodeposition of Nd(0) metal was also proved by the CPE/EQCM analysis. Furthermore, energy-dispersive X-ray and X-ray photoelectron spectroscopy analyses of the blackish electrodeposits obtained by the CPE/EQCM measurements were identified as primarily metallic neodymium because the Nd 3d5/2 spectrum was detected within 980.5–981.5eV.

ChemInform Abstract: Syntheses, Structure Elucidation, and Characterization of the Borate‐Nitrates RE[B5O8(OH)(H2O)] NO3·2H2O [RE: Nd (x = 0.85), Sm (x = 0)

AbstractNd[B5O8(OH)(H2O)0.85] NO3·2H2O (I) and Sm[B5O8(OH)]NO3·2H2O (II) are prepared by hydrothermal reaction of Nd(NO3)3·6H2O or Sm(NO3)3·6H2O, and H3BO3 as reactant and flux in a 1:5 molar mixture without the need for additional H2O (autoclave, 513 K, 3 d).

Crystal structure, fluorescence spectroscopy, and electrochemical property of two neodymium coordination polymers with phenoxy acids

Two nine-coordination coordination polymers of neodymium, [Nd2(p-C8H4O4)(o-C8H4O4)2 • 4H2O]n (I), [Nd2(C10H4O8)(C10H2O8) • 2H2O]n (II), have been prepared by hydrothermal reaction of Nd(NO3)3 • 6H2O with terephthalic acid and phthalic acid, or benzenetetracarboxylic anhydride and determined by means of IR, UV, fluorescence, TG-DTA, cyclic voltammetry (CV) and X-ray single-crystal diffraction methods (CIF files CCDC nos. 1006206 (I), 979309 (II)). Yellow-green luminescence could been observed at 391 nm (λex = 305 nm) for complex I and 370 nm (λex = 331 nm) for the complex II. The emission of complexes I and II may be due to the π* → n transition, which may be assigned to the ligand-to-metal charge-transfer bands. Compared with complex II, the complex I exhibits a stronger fluorescence intensity for the different coordinated environment. Cyclic voltammetric measurement of the two compounds reveal that the compounds both have a couple of irreversible redox peak, indicating that the two polymers were both corresponded to the unusual Nd(III)/Nd(V).

Electrochemical and thermodynamic properties of Nd (III)/Nd (0) couple at liquid Zn electrode in LiCl-KCl melt

The electrode reactions of Nd (III)/Nd couple at liquid Zn and Zn-coated W electrodes in LiCl-KCl melt were investigated in the temperature range of 707–784K. In the both cases, the electrochemical reduction of Nd (III) was observed at a more positive potential than that on an inert W electrode, due to the low activity of Nd in the metal phase. Cyclic voltammetry (CV) recorded at the liquid Zn electrode suggests the existence of a quasi-reversible reaction. The activity coefficient and apparent standard potential have been obtained. On the Zn-coated W electrode, the formation of five obvious non-homogeneous Nd-Zn intermetallic compounds could be observed through CV and open circuit chronopotentiometry (OCP) measurements and the thermodynamics of these intermetallic compounds was also investigated. Electromotive force (emf) measurements for the Nd-Zn intermetallic compounds in two-phase coexisting states were also carried out in the temperature range of 707–784K. Moreover, the standard formation Gibbs energies and the standard equilibrium constant of each Nd-Zn intermetallic compound were also calculated and the thermodynamic stabilities of these compounds at our experimental temperatures were evaluated.

Controlled synthesis of NdF3 and NaNdF4 micro- or nanocrystals by one-pot microwave-assisted hydrothermal reaction

NdF3 nanoflakes and hexagonal NaNdF4 nanorods were successfully prepared in a facile manner by the one-pot microwave-assisted hydrothermal reaction of Nd(NO3)3·6H2O and NaF within 3 h at pH = 1 and pH = 3–10, respectively. Ethylenediaminetetraacetic acid disodium salt (C10H14N2O8Na2·2H2O, EDTA–2Na) was used as the morphology-controlling agent. The size, morphology, and crystallinity of the resulting nanocrystals can be easily tuned by adjusting the reaction temperature and time. The as-prepared NdF3 nanoflakes and NaNdF4 hexagonal prisms were characterized by X-ray diffraction and scanning electron microscope. All nanocrystals exhibited a typical hexagonal phase, and their crystallization improved with increasing reaction temperature and reaction time. A strong emission spectrum was observed at approximately 850–900, 1060, and 1330 nm for both NdF3 nanoflakes and NaNdF4 nanorods under a laser excitation of 354 nm, indicating that Nd3+ exhibits high luminescence in these two nanocrystals.

Electrochemical analyses of diffusion behaviors and nucleation mechanisms for neodymium complexes in [DEME][TFSA] ionic liquid

ABSTRACT The electrochemical and nucleation behavior of Nd(III) in the ammonium-based ionic liquid (IL), N,N -diethyl- N -methyl- N -(2-methoxyethyl) ammonium bis(trifluoromethyl-sulfonyl) amide, [DEME] [TFSA], were investigated in this study. The cathodic reaction of Nd(III) [Nd(III) + 3e − → Nd(0)] was observed at −3.30 V vs. Ag/Ag(I) using cyclic voltammetry at 353 K. The diffusion coefficient of Nd(III) was estimated to be 1.35 ± 0.10 × 10 −13 m 2 s −1 at 353 K using semi-integral and semi-differential analyses. The initial process of Nd electrodeposition was also evaluated by chronoamperometry, indicating that the initial nucleation and growth of Nd on the Pt electrode occurred via instantaneous nucleation at −3.40 V. As the applied potential became more negative, the mechanism changed from instantaneous to progressive nucleation. The number density of Nd nuclei in the initial stage of nucleation decreased as the overpotential increased. Furthermore, the electrodeposition of Nd was carried out under the conditions of −3.40 V and −3.60 V at 353 K. SEM observations of the electrodeposits were consistent with the series of results obtained by chronoamperometry. The electrodeposits consisted mainly of Nd metal and oxide mixtures, whereas bonding with the light elements (C, F, and S) of the IL was suppressed, as demonstrated by EDX and XPS. The results suggested that sufficient dehydration and control of the water content of the electrolyte are important factors for obtaining metallic Nd with high purity.

High-coercivity Nd–Fe–B thick films without heavy rare earth additions

The magnetic properties and microstructures of two Nd–Fe–B thick films with different Nd contents have been studied. The films were deposited in the amorphous state and were crystallized by post-deposition annealing. Both films show a strong 〈001〉 fibre texture out-of-plane. The film with the higher Nd content has a large room temperature coercivity of 2.7T, while the one with the lower Nd content has a room temperature coercivity of only 0.7T. The difference in coercivity may be explained by the fact that the film with the higher Nd content exhibits a continuous Nd-rich grain boundary phase, giving better isolation of the Nd2Fe14B grains with respect to magnetic exchange interactions. The extrusion of Nd-rich liquid to the top surface of the film with high Nd content during post-deposition annealing led to the formation of ripples in the Ta capping layer, indicating that the films are under compressive stress. This stress-induced flow of the Nd-rich material up through the film explains the excellent distribution of the Nd-rich grain boundary phase. Atom probe tomography has revealed the presence of Cu in the Nd-rich grain boundary phase, explaining the formation of the liquid phase at the relatively low temperature of 550°C due to the eutectic reaction of Nd and Cu.

Bimetallic lanthanide amido complexes as highly active initiators for the ring-opening polymerization of lactides

A series of neutral bimetallic lanthanide amido complexes supported by rigid phenylene bridged bis(β-diketiminate) ligands were synthesized, and their catalytic behavior for the polymerization of L-lactide and rac-lactide was explored. The amine elimination reaction of Ln[N(TMS)(2)](3)(μ-Cl)Li(THF)(3) with PARA-H(2), [PARA-H(2) = 2[2,6-(i)Pr(2)C(6)H(3)NHC(Me)C(H)C(Me)N]-(para-phenylene)] in a 2:1 molar ratio in THF at 25 °C afforded the corresponding bimetallic lanthanide amido complexes PARA-{Ln[N(SiMe(3))(2)](2)}(2) [Ln = Nd(1), Sm(2), Y(3)] in high isolated yields. Similar reaction of Nd[N(TMS)(2)](3)(μ-Cl)Li(THF)(3) with META-H(2), [META-H(2) = 2[2,6-(i)Pr(2)C(6)H(3)NHC(Me)C(H)C(Me)N]-(meta-phenylene)] at 90 °C in toluene for about 48 h gave META-{Nd[N(SiMe(3))(2)](2)}(2) (4). Complexes 1-4 were well characterized by elemental analysis, IR spectroscopy, and their definitive structures were confirmed by an X-ray crystal structure analysis. The coordination environment and coordination geometry around the metal atoms are similar in these complexes. Each of the metal atoms is four-coordinated with two nitrogen atoms from the N,N-chelating β-diketiminate unit, and two nitrogen atoms from two (Me(3)Si)(2)N- groups to form a distorted tetrahedron. These complexes can serve as highly active initiators for L-lactide polymerization in toluene. In addition, they also showed high activity towards rac-lactide polymerization in THF at room temperature, giving heterotactic-enriched polymers (P(r) ≈ 0.70), and complex 4 displays obviously higher activity in comparison with complex 1.

Investigation of in Situ Oxalate Formation from 2,3-Pyrazinedicarboxylate under Hydrothermal Conditions Using Nuclear Magnetic Resonance Spectroscopy

We have investigated the assembly of a two-dimensional coordination polymer, Nd(2)(C(6)H(2)N(2)O(4))(2)(C(2)O(4))(H(2)O)(2), that has been prepared from the hydrothermal reaction of Nd(NO(3))(3)·6H(2)O and 2,3-pyrazinedicarboxylic acid (H(2)pzdc). In situ oxalate formation as observed in this system has been been investigated using (1)H and (13)C nuclear magnetic resonance spectroscopy, and a pathway for C(2)O(4)(2-) anion formation under hydrothermal conditions has been elucidated. The oxalate ligands found in Nd(2)(C(6)H(2)N(2)O(4))(2)(C(2)O(4))(H(2)O)(2) result from the oxidation of H(2)pzdc, which proceeds through intermediates, such as 2-pyrazinecarboxylic acid (2-pzca), 2-hydroxyacetamide, 3-amino-2-hydroxy-3-oxopropanoic acid, 2-hydroxymalonic acid, 2-oxoacetic acid (glyoxylic acid), and glycolic acid. The species are generated through a ring-opening that occurs via cleavage of the C-N bond of the pyrazine ring, followed by hydrolysis/oxidation of the resulting species.

Crystal Structure and Interaction With Bovine Serum Albumin of Rare Earth Complex [Nd(α-C10H7CH2COO)3(C12H8N2)

The title complex [Nd(α-C10H7CH2COO)3(C12H8N2)]2 has been synthesized by the reaction of Nd(NO3)3 · 6H2O with α-naphthyl acetic acid (NAA) and 1,10-phenanthroline (phen). The title complex has an inversion center. The structure of title complex was characterized by the method of IR, elemental analysis, and X-ray single crystal diffraction. The results show that title complex crystallizes in a triclinic system, space group P-1 with cell parameters a=11.7670(10) Å, b=12.6937(13) Å, c = 16.190(19) Å, α = 91.118(2)°, β = 106.290(2)°, γ=115.993(3)°, V = 2058(2)Å3, Dc=1.420 Mg/m3, Z=1, μ=1.313mm − 1, F(000)=890. Each Nd(III) atom is bridged by four α-naphthyl acetate. The Nd(III) atom is nine-coordinated by seven oxygen atoms from five α-naphthyl acetate and two nitrogen atoms from one phen molecule. Hydrogen bonds and aromatic π … π stacking interactions assemble the title complex into a three-dimensional network. After studying the interaction of title complex with bovine serum albumin (BSA) through multi-spectroscopic methods, the binding constant K b, corresponding thermodynamic parameters ΔH, ΔS, and ΔG at different temperatures, were calculated according to the van't Hoff equation. We can find that hydrophobic interaction force plays a major role between the title complex and BSA. The effect of title complex on the conformation of BSA were also analyzed by using synchronous fluorescence and FT-IR spectroscopy.

Template-free synthesis of neodymium hydroxide nanorods by microwave-assisted hydrothermal process, and of neodymium oxide nanorods by thermal decomposition

Based on the 150°C and 1h microwave-assisted hydrothermal reaction of Nd(NO3)3 dissolved in deionized water with pH 10 adjusted by concentrated NH4OH solution, the phase and morphology of the product, characterized by XRD, SEM and TEM analyses, were specified as hexagonal Nd(OH)3 nanorods 50nm in diameter and 700nm long, growing along the [001] direction. TGA analysis showed the evaporation of adsorbed water and dehydration of Nd(OH)3 to synthesize the final pure Nd2O3 product. With 500°C and 2h calcination of the Nd(OH)3 self-template precursor, Nd2O3 nanorods were synthesized, retaining both the morphology and growth direction of the precursor.

Anionic lanthanide complexes supported by a pyrrole-based tetradentate Schiff base ligand: Synthesis, structures and catalytic activity toward the polymerization of ε-caprolactone

The synthesis of the anionic organolanthanide complexes supported by H2bppda (H2bppda=N,N′-bis(2-pyrrylmethylidene)-1,2-phenylenediamine) ligand via different synthetic strategies is reported. Treatment of 1:4 mixture of LnCl3(THF)3 and LiN(SiMe3)2 with 2 equivalents of H2bppda in THF gave complexes of the formula [Li(THF)4][Ln(bppda)2]·THF (Ln=Nd (1·THF), Sm (2·THF), Gd (3·THF), Dy (4·THF), Er (5·THF)) and [Li(THF)5][Yb(bppda)2] (6). Reaction of Nd(BH4)3(THF)3 with 2 equivalents of Na2bppda in THF generated [Na(THF)6][Nd(bppda)2] (7) in good yield. Treatment of 1·THF with 1 equivalent of CoCp2 in THF led to the isolation of [CoCp2][Nd(bppda)2] (8). All of the complexes have been characterized by single crystal X-ray diffraction and elemental analyses. Complexes 1·THF–5·THF are isomorphous and isostructural, and the geometry of the octa-coordinated Ln3+ ion in [Ln(bppda)2]− unit in these complexes is well described as either distorted dodecahedron or distorted bicapped trigonal prism. Lanthanide contraction was observed in 1·THF–5·THF and 6. The structures of complexes 1·THF, 7 and 8 are different from each other due to the variation of the cationic ions. The ring-opening polymerization reaction of ε-caprolactone initiated by 1·THF was conducted; it showed good activity.

Separation of Nd metal by using disproportionation reaction of Nd(II) in molten chlorides

In order to separate neodymium (Nd) from lanthanides in chloride melts, the electrochemical characteristics Nd ions in molten LiCl–CaCl 2 eutectic were studied. The formal redox potentials of the Nd 3+|Nd 2+ and Nd 2+|Nd couples in molten LiCl–CaCl 2 eutectic at 823 K were determined to be −2.745 ± 0.005 and −3.081 ± 0.005 V vs. Cl 2|Cl −. Under the controlled potential electrolysis by applying negative potential to form Nd 2+, Nd 2+ was disproportionated to Nd 3+ and metallic Nd fog according to the reaction; 3Nd 2+ ⇄ 2Nd 3+ + Nd. When a quartz glass was immersed in the melt during the electrolysis, Nd was coated on the quartz surface. The chemical composition of the recovered Nd was analyzed to be Nd metal and Nd 2O 3 by scanning electron microscopy, X-ray diffractometry, and electron probe microanalysis. The same electrolytic method was carried out under the coexistence of Nd 3+ and lanthanum ion (La 3+). Nd 3+ was separated from La 3+ and recovered to be Nd 2O 3.