SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Maowa Zhang,Haiqing Hao,Chenxi Shi,Chongchong Chen,Guoli Zhou,Jingtao Wang,Yijun Cao,Xiangke Han
Nd is a strategic metal, but its extraction and separation process remains a challenging task. Here, ion-imprinted membranes with six-coordinated and semi-rigid imprinted nanocage structure were developed by self-assembling terpyridine monomers in the confined reduced graphene oxide (rGO) nanochannels. The obtained membranes displayed excellent Nd(III) adsorption capacity of 20.6 mg g −1 in the solution including seven rare earth elements (REEs), together with a 7.68 times higher selectivity to Y(III). Experimental measurements and theoretical calculations revealed that Nd(III) was well coordinated to the six pyridine-nitrogen in the nanocage, which showed shorter average coordination bond (0.77 Å) and stronger binding energy (-10.52 eV) than other REEs. These were mainly attributed to the rigid symmetrical crab-type architecture and specific cavity size of bis-terpyridine nanocage. Meanwhile, the limited decomposition of these metastable nanocage derived from 2D confined effect and nanochannel walls with few groups reduced the interference of groups at non-imprinted sites on selective adsorption. The excellent anti-swelling property of rGO framework endowed 7 static adsorption cycles and maintained high selectivity (K' (Nd/Y) > 7). Integrated into account the well-defined semi-rigid sites constituted by non-covalent interactions, this strategy provided a new idea for facile synthesis of imprinted sites with higher selectivity.
研究领域:
材料科学
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环境化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2026
·
IF 9.1
Shuyang Li,Zhou Fang,Qingqing Liu,Jiangjiexing Wu,Peng Gu,Xiaohui Mao,Liping Zhu,Meifang Zhu
Rare earth elements (REEs) are indispensable for advanced technologies, and their recovery from low-concentration industrial wastewater is of great significance for resource utilization and environmental protection. However, the recovery is often hindered by insufficient adsorption capacity and severe interference from coexisting ions. Herein, an ion-imprinted aerogel (PPN@CP-IP) was developed by polymerizing 2-hydroxyethyl 2-methyl-2-propenoate phosphate in the presence of phosphorylated cellulose fibrils using Nd(III) as template. The adsorption kinetics and isotherms were well fitted by the pseudo-second-order and Langmuir models, respectively, indicating chemisorption-dominated monolayer adsorption. PPN@CP-IP exhibited a maximum adsorption capacity of 198.8 mg/g for Nd(III). When the Fe(III) concentration was four times that of Nd(III), the distribution coefficient for Nd(III) remained high at 12202 mL/g. Additionally, after nine adsorption–desorption cycles, the adsorption and desorption efficiencies remained 89.27% and 90.13%, respectively. Adsorption was mainly attributed to electrostatic attraction and coordination between Nd(III) and hydroxyl/phosphate groups. The influencing factors under single-variable and multivariable conditions were investigated using the XGBoost machine learning model. The aerogel was applied in actual waste NdFeB magnet leaching solution, the adsorption capacity of Nd(III) was as high as 167.9 mg/g, while that of iron ions was only 7.3 mg/g. This work provides a robust strategy for highly selective REEs recovery from complex low-concentration wastewater, offering a promising pathway for sustainable rare earth resource recycling and hazardous waste treatment.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2022
·
IF 6.633
Wenfeng Xue,Ronghao Liu,Xiaoxia Liu,Yangyang Wang,Ping Lv,Yanzhao Yang
The development of an environmentally friendly extractant for selective recovery of rare earth elements is critical but still faces significant challenges. Two low viscosity carboxylic acid based ionic liquids [A336][BTA] and [A336][OTA] were synthesized for selective extraction of Nd(III) from waste NdFeB magnets. First, the extraction behaviors of two kinds of ionic liquids were compared under different conditions, such as time, pH value of aqueous phase, dosage of ionic liquids, and concentration of salting-out agent. The optimal extraction condition of [A336][OTA] was optimized by response surface methodology, and the extraction efficiency reached 99.1%. The extraction mechanism was proposed as ion association by UV–Vis spectrum, IR spectrum and 1 H NMR, and was supported from that perspective of quantum chemical calculation. The extraction thermodynamics, kinetics and isothermal model were studied in detail. [A336][OTA] maintained an extraction efficiency of 95.6% even after seven cycles. The extractant shows good selective separation performance in waste NdFeB magnets, and is an extractant with good application prospect. This work has provided an environmentally friendly extractant for the recovery of Nd(III) from waste NdFeB magnets.
研究领域:
化学工程
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材料科学
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环境科学
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DOI
高影响因子
HYDROMETALLURGY
·
2025
·
IF 5.3
Jun Li,Ruihui Wu,Shengjun Tian,Ronghao Liu,Huiying Wei,Yanzhao Yang
The NdFeB magnets are the most widely used permanent magnetic materials in the international arena, and the recovery of Nd(III) from the growing number of waste-NdFeB magnets is becoming increasingly crucial. In this study, a novel synergistic extractant consisting of bis(2,4,4-trimethylpentyl) phosphonic acid (Cyanex 272) and 8-hydroxyquinoline (8-HQ) is proposed for the recovery of Nd(III) from waste-NdFeB magnets. First, the influence of the ratio of the two extractants on the synergistic extraction coefficient was investigated. The coextraction coefficient ratio of the two extractants Cyanex 272 and 8-HQ was 1:1. The extraction behaviors under different conditions, such as the extractant concentration, aqueous phase pH (pH = 5), and oscillation time (1 min), were investigated. Under optimal conditions, the extraction efficiency reached 99.6 %. A chelating extraction mechanism was proposed on the basis of UV–vis spectroscopy, FT-IR spectroscopy, and NMR spectroscopy methods. The excellent extraction efficiency was maintained after five cycles of extraction and stripping, indicating the potential for application in light and heavy rare earth separation processes. Overall, this study aims to provide a new economically viable method for the recovery of Nd(III) from waste-NdFeB magnets.
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高影响因子
HYDROMETALLURGY
·
2022
·
IF 4.217
Yu Deng,Yi Zhang,Yigang Ding
Recovery and separation of rare earth elements was highly crucial but difficult. In this study, a well-designed new ionic liquid named as benzyltributylammonium decanedioate ([N 444Bn ] 2 [SA]) was developed to extract rare earths and separate Sm(III) from the spent SmCo magnets in acetate medium for the first time. To exhibit the superiority of acetate medium, the extraction of Nd(III) and La(III) in three different media were comparatively investigated under different conditions, including equilibrium time, initial pH of aqueous solution, rare earth concentration, extractant concentration, salting-out agent concentration and extraction temperature. The results revealed that the better extractabilities of La(III) were observed in acetate medium rather than those in chloride medium (i.e., 97.6% versus 78.6%), which may be attributed to the low-hydrated nature of acetate ions. Importantly, the back-extraction experiments indicated that 91.4% Nd(III) can be stripped from [N 444Bn ] 2 [SA] by using 1.5 mol/L HOAc, revealing the outstanding reusability of ionic liquid in the industrial separation-stripping cycles. Furthermore, the ion association mechanism was proposed to describe the extraction behavior and confirmed by the slope analysis and FT-IR characterizations in three media. In terms of the SmCoCu mixture separation, the maximal separation factor of Sm(III)/Co(II) was calculated as 3078 in simulated solution. Impressively, the recovery of Sm(III) from the actual SmCo magnets by our dicarboxylate-type ionic liquid was also successfully achieved with a recycling rate of 96.8% and a Sm(III)/Co(II) selectivity of 148, which exhibited the potential application in the separation of Sm(III) from the spent SmCo magnets.
研究领域:
化学工程
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材料科学
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环境科学
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DOI
高影响因子
RSC Advances
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2021
·Vol. 11
·期 45
·27969-27977
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IF 3.361
Yaoyang Liu,Sheng Liu,Zhibin Liu,Chuang Zhao,Chunhui Li,Yu Zhou,Caishan Jiao,Yang Gao,Hui He,Shaowen Zhang
A novel asymmetric diglycolamide N,N-dimethyl-N′,N′-dioctyl diglycolamide (LII) was synthesized. The Nd(III) extraction behavior from HNO3 and loading capability of the solution of LII in 40/60 (v/v)% n-octanol/kerosene were studied. Analyses by the slope method, ESI-MS, and FT-IR indicated that, similar to the previously studied isomer ligand N,N′-dimethyl-N,N′-dioctyl diglycolamide (LI), 1 : 3 Nd(III)/LII complexes formed. Under the same experimental conditions, the distribution ratio and limiting organic concentration of LII towards Nd(III) were smaller than those of LI, but the critical aqueous concentration of LII was larger, which implies that LII exhibited poorer extraction and loading capabilities towards Nd(III) than LI, and LII has a tendency to be less likely to form the third phase. The quasi-relativistic density functional theory (DFT) calculation was performed to provide some explanations for the differences in their extraction behaviors. The electrostatic potential of the ligands indicated that the electron-donating ability of the amide O atoms in LII displayed certain differences compared with LI. This inhomogeneity in LII affected the interaction between LII and Nd(III), as supported by QTAIM and bonding nature analysis, and it seemed to reflect in the extraction performance towards Nd(III).
研究领域:
化学
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材料科学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Changchao Su,Yuheng Sun,Hongqun Tang,Youbin Wang,Fuxu Tao,Zhengbin Xu,Chunhua Wei,Zezuo Jiang,Shiqiang Wei
Rare-earth metal neodymium is an important raw material for NdFeB permanent magnets, and its demand has significantly increased in recent years. Molten salt electrolysis is the main method for the production of metal neodymium, so the study of the electrodeposition process of neodymium ions in molten salt at the cathode is of great significance for the production of metal neodymium. In this paper, the electrochemical deposition process of neodymium ions on a tungsten working electrode was studied in a LiF-NdF 3 -Nd 2 O 3 molten salt system using electrochemical methods such as cyclic voltammetry and open circuit potential. Additionally, the influence of LiF content in the molten salt on the electrodeposition process was analyzed. The experimental results indicate that the reduction of neodymium ions in the LiF-NdF 3 -Nd 2 O 3 molten salt system consists of two stepwise quasi-reversible redox reactions: Nd(III) → Nd(II) and Nd(II) → Nd(0). The corresponding reduction peak potentials are −0.78 V and −1.19 V, respectively. The Nd(III) → Nd(II) reaction is solely diffusion-controlled, while the Nd(II) → Nd(0) reaction is governed by both surface control and diffusion control in the electrochemical process. The increase in LiF content in the molten salt leads to a shift of the cathodic overpotential in the positive direction. When the LiF content is high, the reduction of neodymium ions on the electrode becomes unstable, making it unfavorable for the deposition of metal neodymium on the tungsten electrode.
研究领域:
材料科学
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电化学
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高影响因子
JOURNAL OF CHEMICAL SCIENCES
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2022
·Vol. 134
·期 3
·1-11
·
IF 2.15
LIU XIAOJUAN,LI MINGMING,YANG SHUMING,YANG YAYA,NIE JIANG,XUE YUBING,OUYANG YINGGEN,XIAO SONGTAO
The increasing demand for neodymium (III) and samarium (III) due to their extensive high-tech applications has drawn much attention to their recovery. In this work, the copper-based metal-organic framework HKUST-1 was prepared and used for the adsorption of neodymium (III) and samarium (III) in the media of an aqueous solution. The maximum adsorption capacity of the material for neodymium (III) and samarium (III) was 284.11 and 503.45 mg g −1 at a pH of 5.5, respectively. The adsorption removal rate could achieve nearly 100% at the solid-to-liquid ratio of 1.0 g L −1 , which is relatively excellent among such adsorbents used for rare earth elements uptake. The mechanism and reversibility of neodymium (III) and samarium (III) adsorption were systematically investigated by X-ray diffraction, Fourier transforms infrared spectroscopy, Raman spectra, and X-ray photoelectron spectroscopy, suggesting that the mechanism for the adsorption was ion exchange and complexation between trivalent rare-earth ions and the oxygen atom in the hydroxyl group. The reason behind the material displaying a more robust affinity for samarium (III) may be caused by the energy difference between f n and f n+1 states of samarium (III) was larger than that of neodymium (III), thus forming stronger covalent bonding. Graphical abstract HKUST-1 exhibited high adsorption capacity towards Nd (III) and Sm (III). The reason behind the material displaying a more robust affinity for Sm(III) was caused by that the energy difference between f n and f n+1 states of Sm(III) was larger than that of Nd(III), thus forming stronger covalent bonding.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
SOLVENT EXTRACTION AND ION EXCHANGE
·
2021
·
IF 2.513
Yifu Hu,Chuan Lu,Qi Chen,Yaoyang Liu,Yu Zhou,Caishan Jiao,Meng Zhang,Hongguo Hou,Yang Gao,Guoxin Tian
In this paper, pertraction of Nd(III) and U(VI) from nitric acid media through a flat-sheet supported liquid membrane (FSSLM) was studied by using a self-made liquid membrane device, respectively, with N, N’-dimethyl-N, N’-dioctyl-3-oxadiglcolamide (DMDODGA) diluted in 40/60 (V/V)% n-octanol/kerosene as the carrier. The effects of various factors, such as the acidity of the feed and stripping phases, neodymium concentration, uranium concentration, DMDODGA concentration are discussed. The optimized conditions for Nd(III) transport were found to be 3 M HNO3 in the feed phase, 0.5 M HNO3 in the stripping phase, 0.48 M DMDODGA in n-octanol/kerosene as the carrier. When the initial concentration of Nd(III) was 1 × 10−4 mol/L, the transport rate of Nd(III) was 86.4(±2.2)%. Compared with Nd(III), the liquid membrane was less effective in the transport of U(VI), the highest transport rate of U(VI) was 57.2 (±2.6)%.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2020
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IF 7.489
Yilin Wu,Rongxin Lin,Faguang Ma,Wendong Xing,Jianming Pan
Three-dimensional (3D) basswood materials, for the first time, were successfully used for the construction of rare-earth Nd(III)-imprinted nanocomposite membranes. Herein, polydopamine (PDA)-modified layers could be initially synthesized on basswood surfaces. After the double-bonded modification procedure, the 3D wood-based ionic imprinted membranes (3DW-IIMs) system was finally accomplished by developing a re-modified two-step-temperature free radical polymerization process. The as-design PDA@basswood surface structure was first proposed and applied as imprinting-initiated factors for the preparation of Nd(III)-imprinted sites. Importantly, excellent rebinding capacity (120.87 mg g −1 ), adsorption kinetics and permselectivity coefficients (more than 10) were achieved successfully. Furthermore, an important research result had also been found that the PDA-modified layers caused significant promotions to the rebinding capacities of the as-prepared 3DW-IIMs, that is to say, more and more Nd(III)-imprinted sites could be synthesized because of the PDA-modified surfaces. The as-obtained selective rebinding and separation results together with the green natural wood-based materials strongly demonstrated that our synthesis methodology of 3DW-IIMs had great potential for applications in various fields of rare earth separation, chemical industry, and environment protection.
研究领域:
材料科学
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环境科学
·
化学工程
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）