JOURNAL OF MEMBRANE SCIENCE
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2021
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IF 8.742
Ye Zhang,Yong Gao,Peng Wang,Yichen Xu,Zhenming Yang,Jinsong Zhang
Membrane contactors have received considerable attention for extraction due to non-dispersive mass transfer through porous membranes. The past decades have seen the rapid development of organic hollow fiber membrane contactors, but very few studies have explored the applications of inorganic membranes in extraction, possibly due to their high costs. In this work, a novel SiC foam material with a hollow skeleton and microporous strut wall was used as a ceramic membrane contactor (HS-FCMC) for rare earths extraction. The foam's structure was characterized by scanning electron microscopy (SEM), X-ray micro-computed tomography (micro-CT), and mercury intrusion porosimetry (MIP). The flow and concentration fields inside and outside the foam cell were simulated by computational fluid dynamics (CFD), and the mass transfer through the ceramic membrane was analyzed. Based on the nitric acid–Ce 3+ /Pr 3+ –P507–kerosene chemical system, the extraction efficiency of Pr 3+ and Ce 3+ using the HS-FCMC reached 96.13% and 92.86%, respectively. A comparison study with poly tetra fluoroethylene (PTFE) hollow fibers was also conducted. The results indicate that the HS-FCMC is suitable for rare earths extraction due to the multiscale porous structure and chemical stability of the hollow-skeleton SiC foam. This research advances the knowledge of inorganic membrane extraction methods.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2018
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IF 3.927
Junlian Wang,Xinyu Liu,Jiashuai Fu,Meiying Xie,Guoyong Huang,Huajun Wang
Scientists have always been seeking more efficient extractants for rare earths extraction and separation, especially for heavy rare earths. In this paper, a novel extractant (2,4-dimethylheptyl)(2,4,4′-trimethylpentyl)phosphinic acid (USTB-2) was synthesized. The structures of the intermediate and USTB-2 were characterized by 31 P NMR, 1 H NMR, FT-IR and ESI-MS. Its p K a was 5.62. Its extraction ability was between Cyanex 272 and P507. Its extraction mechanism was cation exchange. Its extraction capacity was larger than that of Cyanex 272 and lower than that of P507. Its solubility in 3 mol/L HCl and deionized water was 11.2 mg/L and 19.0 mg/L, respectively. The Lu(III) loaded in USTB-2 solution can be easily stripped by HCl, HNO 3 and H 2 SO 4 . It has good separation performance for heavy rare earths. Its average separation factor ( β ¯ ) for adjacent heavy REs from Gd to Lu was 2.18. For some heavy RE couples like Er/Ho, Yb/Tm and Lu/Yb (especially for Lu/Yb), USTB-2 possesses even better separation performance than Cyanex 272. Its extraction efficiency for nonferrous metal ions was in the order Al > Gd > Zn > Nd > La > Co > Cu. The separation factors of Al/Gd, Gd/Zn, Zn/Nd, La/Co by USTB-2 were 2.67, 5.39, 3.35 and 26.67, respectively.
研究领域:
化学
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材料科学
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DOI
高影响因子
JOURNAL OF RARE EARTHS
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2022
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IF 4.632
Junlian Wang,Guodong Xu,Wen Xu,Jianguo Cui,Yufu Chen,Ziyong Chang
The relationship between dialkylphosphinic acid structure and their loading capacity for HREEs and emulsification phenomena has rarely been studied. In this paper, we took Lu extraction as an example to study the effect of β , γ , δ -substituents of dialkylphosphinic acids on their loading capacity and anti-emulsification performance for HREEs. To discuss conveniently, the dialkylphosphinic acids were classified into two groups: β -substituent group (P208, INET-1, P218, USTB-1 and P227) and γ , δ -substituent group (P218, P2132 and Cyanex 272). For β -substituent group extractants, their loading capacities are in the order P208 (299.7 mg/L) ≈ INET-1 (299.5 mg/L) > P218 (270.8 mg/L) >> USTB-1 (163.1 mg/L) > P227 (151.4 mg/L), while their anti-emulsification/gelation performances are just in the opposite order P227 > USTB-1 > P218 > P208 ≈ INET-1 under the studied conditions. For γ , δ -substituent group extractants, their loading capacities are in the order P218 (270.8 mg/L) > P2132 (192.3 mg/L) > Cyanex 272 (131.7 mg/L), while the anti-emulsification performance of P218 is better than those of P2132 and Cyanex 272. The loading capacity data given in the parentheses are obtained through repeatedly extracting Lu from ∼4 × 10 −4 mol/L of Lu aqueous feed solution with initial pH of 2.40 by 0.01 mol/L extractant at phase ratio A/O of 1:1.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
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2024
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IF 6.3
Qiang Wang,Haiqing Hao,Zhengyang Wu,Meng Wang,Zongyu Feng,Yongqi Zhang,Xiangxin Xue,Xiaowei Huang
The MgCl 2 wastewater generated from rare earth extraction and separation process was treated by spray pyrolysis with H 2 O 2 as an additive for the first time, and achieving full recycling of MgCl 2 wastewater. The effect of H 2 O 2 on the spray pyrolysis process, the kinetic of the spray pyrolysis process, and the mechanism of the effect on the activity of MgO powder were investigated. The results showed that H 2 O 2 and the O 2 produced by its decomposition had strong oxidizing property, which contributed to the removal of Cl roots. The kinetic results indicated that the rate determining step of MgCl 2 spray pyrolysis was transformed from chemical reaction to diffusion process after the temperature exceeded 1023 K. The activity study indicated that the doping of Cl led to severe distortion of the MgO grains, and polycrystalline basic magnesium chloride had more defect sites too. Thus, the powder showed high activity. Moreover, the thermal decomposition rate of MgCl 2 reached 99.83 %, the alkalinity of the powder reached 0.044 mol/g, and the iodine absorption value reached 131.81 mg I 2 /g MgO at temperature of 1073 K and amount of H 2 O 2 addition of 1 %. Meanwhile, the high purity hydrochloric acid with concentration of 6.54 mol/L was obtained.
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 RARE EARTHS
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2021
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IF 3.712
Ye Zhang,Yong Gao,Peng Wang,Duo Na,Zhenming Yang,Jinsong Zhang
Extraction reactor is a major research area of interest within the field of rare earths extraction and separation. SiC foam offers excellent material characteristics as well as three-dimensional (3-D) reticulated structure; however, very little research has been carried out on its application in extraction reactor so far. In this work, a static mixer reactor based on SiC foam was designed and demonstrated to extract and separate Ce(III) and Pr(III) from nitric acid media by using 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (P507) as extractant. The structure–performance relationship between SiC foam and extraction performance was studied by experiment combined with computational fluid dynamics (CFD) simulation. The experiment data are in good agreement with the simulation results. Contrast experiment by using a Kenics mixer was carried out, and SiC foam shows better extraction and mass transfer performance. Using the optimal structural SiC foam (pore size D = 2.3 mm, open porosity ε = 85%, foam length L = 80 mm), high extraction efficiency η (Pr(III): 94.6%, Ce(III): 88.5%) and separation factor β (2.27) between Ce(III) and Pr(III) is achieved at a high total throughput of 200 mL/min. Besides, overall volumetric mass transfer coefficient K L a of Pr(III) and Ce(III) are 0.519 and 0.378 s −1 at the residence time τ of 3.6 s, respectively, which reach the high level of microchannel reactors and are better than conventional extractors and other static mixers. SiC foam is found to be applicable as a static mixer for efficient and high-throughput extraction and separation of rare earths.
研究领域:
稀土提取
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分离工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
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