JOURNAL OF RARE EARTHS
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2021
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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
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材料科学
✓ 已验证
DOI
高影响因子
MINERALS ENGINEERING
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2022
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IF 5.479
Wenjie Zhang,Yunpeng Du,Xiong Tong,Xian Xie,Dongxia Feng,Qiang Song
As the most important method for the separation and purification of rare earth elements, solvent extraction is widely used in industry. HDEHP (Di(2-ethylhexyl) phosphoric acid) has become the most commonly used organic extractant because of its high separation factor for rare earth elements and large processing capacity. However, the large amount of ammonia nitrogen wastewater generated during the extraction process creates huge pressure on the environment. The tartaric acid complexing agent has been added to the aqueous phase to improve the extraction performance of HDEHP without saponification. This can effectively avoid the generation of ammonia nitrogen wastewater, which is more in line with the concept of green production. In this study, the effect of tartaric acid on the separation of Pr and Nd by HDEHP in hydrochloric acid and the corresponding mechanism are investigated. This study showed that the addition of tartaric acid could significantly increase the separation coefficient of HDEHP for Pr and Nd. When the tartaric acid concentration was 0.4 mol/L and the solution pH was 2.5, the separation coefficient reached β Nd/Pr = 1.85, which was higher than the separation coefficient of HDEHP for Pr and Nd in the saponification system. Combining Fourier-transform infrared spectroscopy, nuclear magnetic spectroscopy other analysis and detection methods, and in-depth exploration of the extraction mechanism, the final extraction of the compound structures was determined.
研究领域:
化学工程
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环境科学
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稀土分离技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
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2021
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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
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物理化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Qi Zheng,Fan Wang,Jiayu Sun,Mohammed F. Hamza,Qiang Wu,Yehuizi Wu,Ningchao Zheng,Shunyan Ning,Tianjiao Jiang,Deqian Zeng,Hiroshi Watabe,Hao Wu,Yan Wu,Yuezhou Wei,Xiangbiao Yin
As the primary fission product in spent nuclear fuel being generally filed into the high-level liquid waste, the 90 Sr recovered from the reprocessed nuclear fuel could be a significant source for producing 90 Y nuclide (the decay daughter). It presents as one favorable therapeutic radionuclide candidate for radiolabeling of pharmaceuticals in widespread clinical application. Under this situation, a novel silica-based adsorbent (HDEHP/SiO 2 -P) was developed for selective separation of Y 3+ from concentrated Sr 2+ in aqueous solution. Batch adsorption process was investigated under different parameters of acid type and strength, contact time, temperature, ionic concentration and molar ratio etc. It was confirmed that, the HDEHP/SiO 2 -P had highly selective properties toward Y 3+ over Sr 2+ in different acidic medium (i.e., hydrochloric, nitric and acetic acid), with maximum adsorption capacity 34.05 mg Y 3+ /g. Sorption isotherms and uptake kinetics, were better fitting for Langmuir monomolecular layer adsorption mode and the pseudo-second order (PSORE) kinetic model respectively. The sorbent shows high SF Y/Sr of 1.93 × 10 3 even at a Sr-Y molar ratio of 2 × 10 3 . Moreover, dynamic separation of trace amount of Y 3+ from the concentrated Sr 2+ aqueous solution was successfully validated by the column test, in which 100 % Y 3+ was recovered. The produced eluate is characterized by a sharp elution curve without Sr trailing under high acidic conditions of 6 M HCl. All these results would promisingly promote the application of the developed material and chromatographic approach to facilely obtain the adequate quantities of 90 Y with required radiochemical purity for its widespread clinical use.
研究领域:
核化学与放射化学
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材料科学
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医学
✓ 已验证
产品关联
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
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2023
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IF 4.5
Qiang SONG,Wen-jie ZHANG,Xiong TONG,Xian XIE,Zhuo-yue LAN,Yun-peng DU,Yang CAO,Pei-qiang FAN
The kinetics of the bis(2-ethylhexyl) phosphate (HDEHP) extraction of lanthanum and cerium were investigated in a lactic acid complex system. The effects of stirring speed, specific interface area, temperature and concentration of different solution components on the extraction rate were studied using a constant interface cell device. When the stirring speed was 130–180 r/min, the extraction reaction rate was mainly controlled by the chemical reaction, and increased with increasing the specific interface and temperature. The extraction kinetics shows that the extraction reaction conforms to a pseudo-first-order reaction, and the mass transfer process occurs at the interface between the organic and liquid phases rather than in the bulk phase. The Gibbs free energy of the extraction reaction Δ G <0, indicating that the reaction can proceed spontaneously, while the calculation of the apparent activation energy shows that HDEHP is more likely to combine with cerium during extraction.
研究领域:
化学工程
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稀士化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）