JOURNAL OF RARE EARTHS
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2021
·
IF 3.712
Wenjie Zhang,Dongxia Feng,Xian Xie,Xiong Tong,Yunpeng Du,Yang Cao
Solvent extraction is the most important method for rare earth extraction and separation. Currently, di(2-ethylhexyl) phosphoric acid (HDEHP) and 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (HEH/EHP) are widely used in industrial production, but there are still obvious deficiencies that require further research to resolve. In this paper, the unsaponification extraction of light rare earth ions in a hydrochloric acid medium by di(2-ethylhexyl) phosphoric acid-di(1-methyl-heptyl) methyl phosphonate (HDEHP-P350) system was studied. The results show that the addition of P350 reduces the extraction capacity of HDEHP, and also greatly reduces the concentration of acidity required for the back-extraction. It still has a good separation factor for light rare earths without saponification , and the extractant is not easy to emulsify. With an aqueous phase of pH = 2.85, and HDEHP mole fraction X HDEHP = 0.9 (compared with O/A = 2), the separation effect of light rare earth is the best, resulting in the separation coefficient β Ce/La = 3.39, β Pr/Ce = 1.67 and β Nd/Pr = 1.45, respectively. The loaded light rare earth ions extracted by HDEHP-P350 can be easily stripped when 2 mol/L HCl is used as the stripping agent. Finally, the extraction mechanism is discussed using a slope method, and the final structure of the extracted complex is determined to be RECl[(DEHP) 2 ] 2 P350 (o) , based on a combination of infrared spectra and 1 H NMR and 31 P NMR analyses.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2023
·
IF 6
Zhenyu Zhang,Juan Liu,Ting Li,Zhikai Fu,Jinshui Mao,Xiaocheng Li,Sili Ren
Recycling of Nd(III) and Dy(III) from waste NdFeB magnets is increasingly critical in the sustainable development of rare-earth elements (REEs) industry. The efficient separation of Nd(III) and Dy(III) from conventional aqueous solution by solvent extraction (SX) is facing huge challenge due to the high activity, high interfacial tension and the high dielectric constants of water that affect the coordination of REEs with the extractant. Herein, a novel non-aqueous solvent extraction (NASX) system based on neutral extractant P350 was developed to extract Nd(III) and Dy(III) with high extraction efficiency and separation factor. In this extraction system, the majority of water in the aqueous phase was replaced by different low-dielectric-constant polar molecular organic solvents (PMOSs) to reduce the influence of water during extraction. The effect of the type and content of PMOSs, P350 concentration, extract equilibration time and temperature on the separation performance were systematically investigated. It was encouraging to find that the favorable separation factor of Nd(III) and Dy(III) elements ( β Nd/Dy ) was determined to be 201 when extracted from 70 vol% PEG 200 with 0.2 mol/L P350, which was higher than that in traditional extraction from aqueous phase. Slope analysis method was used to determine the extractant stoichiometry and the main species of extraction complex was identified as DyCl 3 ·2L which was verified by Fourier infrared spectroscopy (FT-IR). Furthermore, in the simulation of recovery of NdFeB magnetic immersion solution experiment, the extraction efficiency (E%) of Dy(III) can reach 85 %, while co-extraction of Nd(III) was only 6 % and the β Dy/Nd was as high as 83.4. According to the McCabe-Thiele diagram, 3-stages counter-current solvent extraction was needed to completely extract Dy(III). Moreover, 97.11 % of Nd(III) and 98.5 % of Dy(III) in the loaded organic phase can be sequentially stripped by 0.04 mol/L and 0.4 mol/L HCl, respectively. These results indicated that the developed processes in this work have superior extraction efficiency, large separation factors and excellent stripping stability. Eventually, a P350-PEG 200 extraction system-based separation process was proposed in the hope of providing a novel and low-cost alternative to the efficient recycle of Nd(III) and Dy(III) from end-of-life NdFeB.
研究领域:
化学工程
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材料科学
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环境科学
✓ 已验证
DOI
高影响因子
Minerals
·
2021
·Vol. 11
·期 1
·61
·
IF 2.644
Wenjie Zhang,Xian Xie,Xiong Tong,Yunpeng Du,Qiang Song,Dongxia Feng
Solvent extraction is the most widely used method for separation and purification of rare earth elements, and organic extractants such as di(2-ethylhexyl) phosphoric acid (P204) and di(1-methyl-heptyl) methyl phosphonate (P350) are most commonly used for industrial applications. However, the presence of impurity ions in the feed liquid during extraction can easily emulsify the extractant and affect the quality of rare earth products. Aluminum ion is the most common impurity ion in the feed liquid, and it is an important cause of emulsification of the extractant. In this study, the influence of aluminum ion was investigated on the extraction of light rare earth elements by the P204-P350 system in hydrochloric acid medium. The results show that Al3+competes with light rare earths in the extraction process, reducing the overall extraction rate. In addition, the Al3+stripping rate is low and there is continuous accumulation of Al3+in the organic phase during the stripping process, affecting the extraction efficiency and even causing emulsification. The slope method and infrared detection were utilized to explore the formation of an extraction compound of Al3+and the extractant P204-P350 that entered the organic phase as AlCl[(HA)2]2P350(o).Keywords:Al3+;light rare earths;P204;P350;impurity
研究领域:
化学工程
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材料科学
✓ 已验证
DOI
高影响因子
Separations
·
2025
·Vol. 12
·期 8
·215
·
IF 2.7
Jiuquan Qi,Qianwen Chen,Chuanying Liu,Chengliang Xiao,Shuainan Ni
Due to the nearly identical chemical properties of Lu and Yb, the production of no-carrier-added (NCA)177Lu faces significant challenges in their separation. Achieving efficient and streamlined separation of Lu and Yb is crucial for the production of NCA177Lu. This study systematically investigated the separation performance of the commercial Rext-P350 extraction resin for Lu and Yb. Static adsorption experiments revealed that, at a solid–liquid ratio of 8 g/L, both Lu3+and Yb3+were nearly completely adsorbed, with saturation adsorption capacities of 25.8 mg/g and 21.5 mg/g, respectively. An increase in the nitric acid concentration in the aqueous phase significantly inhibited adsorption, but the separation factor for Lu3+/Yb3+remained above 1.88. The adsorption kinetics followed a pseudo-second-order model (R2> 0.99), with equilibrium reached within 15 min, demonstrating fast adsorption kinetics. Characterization by SEM, FT-IR, and XPS confirmed the chemical coordination between the resin and Lu3+/Yb3+. Dynamic chromatographic separation experiments showed that the Rext-P350 resin exhibited significantly better separation performance for Lu3+/Yb3+compared to 2-ethylhexylphosphoric acid mono-2-ethylhexyl ester (P507) extraction resin. Leveraging the excellent performance of Rext-P350 resin, a two-stage continuous extraction chromatography process was designed, achieving efficient separation of 0.045 mg of Lu3+from 200 mg of Yb3+with a Lu3+purity of 90.9% and a yield of 98.4%. This study provides a feasible separation technique for the purification of NCA177Lu.
研究领域:
核化学
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放射性同位素生产
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分离科学
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无机化学
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核医学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Ruihui Wu,Ronghao Liu,Xiaoxia Liu,Jianwei Zhang,Wenfeng Xue,Yanzhao Yang
The recovery of Nd(III) from NdFeB permanent magnets is gaining increasing attention. In the rare earth elements separation industry, wastewater produced through saponification has become a serious environmental problem. In this work, a novel non-saponification P350-N235 synergistic extraction system was established for the extraction of Nd(III) from nitric acid medium. Almost 100% of Nd(III) was extracted by using a P350-N235 system when the molar fraction (X) of P350 was 0.3. And the synergistic enhancement factor R max reached 60.03. Firstly, the effects of time, pH, volume ratio and other variables were investigated to determine the extraction behaviors. Response surface methodology (RSM) was used to optimize the extraction conditions. The mechanism of synergistic extraction was investigated by FT-IR, UV–vis, NMR methods and ESP maps, indicating that the composition of the extracted complex was Nd(NO 3 ) 3 ·(P350) 2.5 (N235) 2.5 . Then, the extraction thermodynamics and kinetics were also thoroughly investigated, the extraction process is demonstrated to be a spontaneously exothermic reaction. In the NdFeB leaching solution, the synergistic system showed excellent separation factor (β) for Nd/Sm (1.43), Nd/Gd (7.33), and Nd/Dy (9.81). Finally, after 5 cycles, the P350-N235 synergistic system maintained high extraction efficiency. In conclusion, this study overcame the saponification problem in traditional extraction techniques and proposed an environmentally friendly green extraction system.
研究领域:
环境科学
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化学工程
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材料科学
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稀土元素分离
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2021
·
IF 2.328
Wenjie Zhang,Xian Xie,Xiong Tong,Shengdong Zhang,Yunpeng Du,Yang Cao,Dongxia Feng
The extraction kinetics of lanthanum (III) from a chloride medium by bis(2-ethylhexyl) phosphate(HDEHP) and dimethylheptyl methyl phosphate(P350) in the presence of sulfonated kerosene are investigated using a Lewis cell. The effects of the stirring rate, temperature, and specific interfacial area on the extraction rate are investigated. The results show that the extraction process is controlled by diffusion and chemical reactions in the interfacial area rather than in the bulk phase. The apparent activation energy and the changes in the enthalpy, entropy, and Gibbs free energy of the extraction reaction are calculated using the Arrhenius equation and transition state theory. The rate equation derived from the experimental results is similar to that of the interface reaction model. A mass transfer model with a rate-control step is proposed. This study provides guidance and data support for an HDEHP-P350 system in industrial production applications.
研究领域:
化学工程
·
物理化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）