HYDROMETALLURGY
·
2021
·
IF 4.156
Linquan Sun,Hongdong Yu,Fancheng Meng,Tao Qi,Shili Zheng,Yihe Peng,Lina Wang
Niobium consumption has burgeoned owing to the increasing application of niobium in critical industries, including the aerospace and oil and gas industries. Conventional metallurgical technologies and separation methods for niobium extraction use highly concentrated HF, which is hazardous to both humans and the environment. A solvent extraction system comprising trioctyl tertiary amine (N235) and 4-methyl-2-pentanone (MIBK) that can extract and separate niobium from an oxalate-containing H 2 SO 4 solution is proposed in this paper. Niobium solutions tend to contain titanium and iron impurities; therefore, the effects of various conditions on the separation of the three elements were investigated. The extraction mechanism and thermodynamics of the process were also examined. Over 82% niobium was extracted at an organic-to-aqueous phase ratio of 1:1 and the H + concentration of 8.29 mol/L using an organic phase with 50 vol% N235 and 50 vol% MIBK as the extractants at 20 °C. Only 18.4% titanium and 3.35% iron were co-extracted. Two stripping processes, both of which further separated niobium and titanium, are also proposed herein. The possible composition of the niobium-containing extraction complex was [(R 3 NH)·NbO(C 2 O 4 ) 2 (H 2 O) 2 ], as supported by a Fourier transform infrared spectroscopy (FT-IR) analysis and ultraviolet–visible (UV–vis) spectrophotometry . The extraction mechanism was inferred to be the association of R 3 NH + in N235 with the [NbO(C 2 O 4 ) 2 (H 2 O) 2 ] − from the acidic niobium-containing solution, and the stripping mechanism was concluded to be anion exchange. The enthalpy change (∆H o ) of the extraction system was −11.0 kJ/mol at 288.15–313.15 K, which indicated that niobium extraction from the H 2 SO 4 solution with oxalate using N235 and MIBK was an irreversible exothermic process.
研究领域:
冶金学
·
化学工程
✓ 已验证
DOI
高影响因子
Metals
·
2025
·Vol. 15
·期 5
·468
·
IF 2.5
Shuo Tian,Jing Song,Hongqian Sun,Congcong Zhao,Zhiyu Zhang,Mingming Han,Tao Qi
Zirconium (Zr) and hafnium (Hf) are very important in nuclear and high-temperature applications, but their similar physical and chemical properties bring great challenges to separation. The current extraction methods have defects, such as low efficiency at high metal concentration. In this article, a zirconium (Zr)/hafnium (Hf) solvent extractive separation from sulfuric acid solutions using trioctylamine (TOA) as the extractant was researched at room temperature. The aqueous solution is prepared using zirconium sulfate (containing Hf), and the concentration of metal ions (Zr4+and Hf4+) was about 1.096 mol·L−1. The effects of the aqueous acidity, the concentration of TOA, the contacting time, and the organic to aqueous O/A ratio on the separation of Zr and Hf were investigated. It is observed that the Zr can be extracted in the organic phase selectively, and the optimal conditions were: TOA concentration of 40 vol%, organic to aqueous O/A ratio of 3, contacting time of 5 min. Under these conditions, the single-stage extraction rate of Zr is 61.23%, while the Hf is almost not extracted. The mechanism of Zr extraction by TOA was studied through the saturation capacity and slope methods. Based on the results, it is believed that the structure of the extracted complex may be [R3NH]2[Zr(SO4)3]. This study provides a new approach for the development of industrialized Zr-Hf separation.
研究领域:
化学工程
·
核工业
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Lianjun Song,Xueyu Wang,Dongqi Wang,Qian Xiao,Haowei Xu,Qiuju Li,Lanlan He,Songdong Ding
The synthesis, Eu 3+ complexation, and selective solvent extraction of Am 3+ over Eu 3+ in nitric acid solution by 2-carboxamido-6-(1 H -pyrazol-3-yl)-pyridines (A-PzPy) ligands were described. Without the aid of any lipophilic anion source, A-PzPy ligands in methyl isobutyl ketone (MIBK) diluent demonstrated a more favorable affinity of Am 3+ than Eu 3+ at high acidity levels. Slope analysis showed the formation of 1:2 metal/ligand extracted species. The extraction was a spontaneous exothermic process. The analyses of fluorescence titration, Fourier transform infrared (FT-IR), Raman, time-resolved laser fluorescence spectrum (TRLFS), electrospray ionization mass spectrometry (ESI-MS), conductivity and microcalorimetric titration revealed that the composition of complex is [Eu(NO 3 ) 2 (H 2 O)∙2(Et- p -Tol-A-PzPy)](NO 3 ). Combining the results of solvent extraction and complexation study, the extraction mechanism was proposed. Furthermore, the stability constants (log β ) and thermodynamic parameters (Δ H , Δ S , Δ G ) for complexation of Eu 3+ with Et- p -Tol-A-PzPy were also presented.
研究领域:
化学
·
核化学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2016
·
IF 3.926
Yanliang Chen,Yuezhou Wei,Linfeng He,Fangdong Tang
To separate thorium and uranium in nitric acid solution using anion exchange process, a strong base silica-based anion exchange resin (SiPyR-N4) was synthesized. Batch experiments were conducted and the separation factor of thorium and uranium in 9 M nitric acid was about 10. Ion exchange chromatography was applied to separate thorium and uranium in different ratios. Uranium could be eluted by 9 M nitric acid and thorium was eluted by 0.1 M nitric acid. It was proved that thorium and uranium can be separated and recovered successfully by this method.
研究领域:
化学工程
·
放射化学
✓ 已验证
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2014
·
IF 3.065
Huang Huang,Songdong Ding,Dongping Su,Ning Liu,Jieru Wang,Mengling Tan,Jianen Fei
N , N , N ′, N ′, N ″, N ″-hexaoctylnitrilotriacetamide (NTAamide(C8)) and N,N,N ′ ,N ′ ,N ″ ,N ″-hexabutylnitrilotriacetamide (NTAamide(C4)) were synthesized for selective solvent extraction of Th(IV) from U(VI) and lanthanides(III) (Lns(III)) and for coordination between Th(IV) and NTAamide, respectively. NTAamide(C8) exhibits excellent extraction power and selectivity toward Th(IV) over U(VI) and Lns(III) in a wide range of acidity from 0.1 to 10.0 M HNO 3 . Very high SF Th/M in the range between 2.5 × 10 2 and 10 × 10 3 was observed. Slope analysis shows that Th(IV), U(VI) and Lns(III) were all extracted as mono-solvated species at 3.0 M HNO 3 . The thermodynamic parameters describing the extraction of Th(IV) indicate that the process is endothermic and spontaneous at 298 K. The single-crystal X-ray diffraction observations also establish that 1:1 complex is formed between NTAamide and thorium nitrate, which are in good accordance with the solvent extraction results, and NTAamide is coordinated with Th(IV) in a tetradentate coordination mode.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2020
·Vol. 22
·期 24
·8728-8733
·
IF 9.48
Qun Liu,Dan Pan,Tingting Ding,Mengchao Ye,Fengjiao He
The spent pickling solution, which comes from the pickling process of iron and steel, is indispensable in the manufacturing industry. Iron gets dissolved in the acid solution during the pickling process. When the concentration of metal ions in the acid solution accumulates to a certain value, it cannot to be used to wash iron and steel materials and becomes spent pickling solution that should be treated before discharge. At present, spent pickling solutions are treated via neutralization precipitation techniques in industries. This treatment method has a large discharge of wastewater, and the cost is high due to which it cannot meet the needs of green cycle in industry production. In this study, a new method, which is based on the formation of quaternary ammonium salt precipitate in a strong acid solution, is proposed to treat the spent pickling solution. The spent pickling solution was recycled and reused by precipitation separation of iron ion. The quaternary ammonium salt was recycled by dissolving the obtained precipitate in an alkali solution. The new ferric hydroxide precipitate formed and quaternary ammonium salt was returned to the solution. In the whole process, only a few amount of alkali was consumed. The removal rate of iron ion was up to 99.72%. Compared with the traditional neutralization precipitation method, the acid is not consumed and it can be reused; the alkali was consumed only for the precipitation of iron ions, not for the neutralization of the acid. The proposed method is an effective and economic method for the recovery of the spent pickling solution. It is expected to satisfy the requirements of green cycle and environmental protection in industry production.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Nuclear Science and Techniques
·
2020
·Vol. 31
·期 4
·1-13
·
IF 1.556
Zhang Shi-Chang,Ning Shun-Yan,Zhou Jie,Wang Si-Yi,Zhang Wei,Wang Xin-Peng,Wei Yue-Zhou
A porous silica-polymer-based adsorbent, iso Bu-BTP/SiO 2 -P, was prepared by a vacuum impregnation method and used for the recovery of ruthenium, rhodium, and palladium from nitric acid solution. The experimental results revealed that iso Bu-BTP/SiO 2 -P exhibited unique adsorption properties such as high saturation adsorption capacity (Ru: 0.35 mmol g −1 , Rh: 0.32 mmol g −1 , Pd: 1.05 mmol g −1 ) and excellent selectivity over other metal ions, such as lanthanides (SF PGM/ M > 40) in 1 M HNO 3 solution. The adsorption process conformed to the pseudo-second-order model and Langmuir model. From the UV, FTIR, and XPS analyses, it can be concluded that the strong affinity between functional groups (C–N=C) and metal ions as well as NO 3 − played a role in coordination during the adsorption process. Furthermore, the desorption behavior was studied, and it was found that the adsorbed Pd, Rh, and Ru could be eluted with a 0.01 M nitric acid–0.1 M thiocarbamide solution, 5 M hydrochloric acid, and sodium hypochlorite (CP) solution, respectively. Finally, based on those findings, a simple process for the separation and recovery of Pd, Rh, and Ru from high-level liquid waste using iso Bu-BTP/SiO 2 -P was designed and proposed.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2016
·
IF 1.083
Mei Zhang,Qingye Yan,Yunbin Zhao
In the present article, a new separation system was employed for the extraction of cadmium from nitric acid solutions for the first time. Phosphine oxide, tris[(dibutylamino)methyl]-(7CI,8CI),which contains nitrogen atoms and phosphorus atom in molecular, was used as extractant. The influence of the following parameters was investigated: the organic/aqueous phase ratio (O/A), pH, contact time, temperature, the concentration of extractant, cadmium (Ⅱ), sodium nitrate and sodium chloride. Results demonstrated that quantitative extraction of cadmium was feasible from 50 mg/L cadmium feed solution in a single stage at pH 3.0, 15 min and O/A phase ratio 1:5 with 20% extractant in cyclohexane diluent. The cadmium extraction isotherm under different cadmium ion concentrations was established. The loaded cadmium could be stripped by 4 mol/L ammonium chloride aqueous solutions. A contrast study was carried out, and the results indicated that phosphine oxide, tris[(dibutylamino)methyl] –(7CI,8CI), could take the place of commercial organo-phosphorous extractants in the process of cadmium(II) extractions for its effectivity, stability and low price.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Linquan Sun,Xukun Zhang,Lina Wang,Hongdong Yu,Fancheng Meng,Tao Qi,Yihe Peng
A fluoride-free solvent extraction method for niobium separation in leached sulfuric mother liquor of ilmenorutile was proposed in this paper. The extraction system comprising trioctyl tertiary amine (N235) and 4-methyl-2-pentanone (MIBK) demonstrated good extraction efficiency and selectivity of niobium over titanium and iron impurities in sulfuric acid–oxalate solutions. Details of extraction, scrubbing, and stripping processes were investigated herein, and its practical effectiveness in both batch and multi-stage simulated counter-current modes was verified. Over 73.8% niobium was extracted under optimum conditions, and only 2.8% titanium and 1.7% iron were co-extracted. The recovery of niobium reached 99.1% in the four-stage simulated counter-current extraction tests. In the three-stage simulated counter-current stripping tests, the stripping efficiency of niobium reached 99.7% with 2.0 mol/L HNO 3 . Qualified niobium oxide products were prepared. The enthalpy change, entropy change, and the standard Gibbs free energy change (Δ H o , Δ S o , and Δ G o , respectively) corroborated the exothermicity, orderliness, and spontaneity of the reaction. The possible composition of the extraction complex was [NbO(C 2 O 4 ) 2 (H 2 O) 2 ] − , as supported by a Fourier transform infrared spectroscopy and ultraviolet–visible spectrophotometry. The extraction mechanism was inferred to be the outer-sphere complexation through physical binding which was the association of R 3 NH + in N235 with the [NbO(C 2 O 4 ) 2 (H 2 O) 2 ] − . A preliminary mass balance indicated that 203.92 g Nb 2 O 5 was generated from 1000 g raw material ilmenorutile.
研究领域:
冶金学
·
化学工程
✓ 已验证
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2014
·Vol. 41
·期 10
·7073-7093
·
IF 1.54
Lv T. M.,Zhu S. H.,Guo L.,Zhang S. T.
The inhibiting effect of indole on the corrosion of mild steel Q235 in 0.1 M H 2 SO 4 was investigated through different approaches including weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscope experiments, and theoretical calculations. Polarization curves reveal that the indole acts as a mixed-type inhibitor and the reaction mechanism in respect of either hydrogen evolution or mild steel dissolution has not been modified. EIS results imply that the water molecules adsorbed on the steel surface are substituted by the indole molecules and the inhibiting behavior of indole is probably due to the formation of an adsorptive film on the steel surface. Thus the thermodynamic and kinetic parameters are determined and discussed to give better understanding of the adsorption process. Theoretical calculations are also discussed in light of the optimized molecular structure of indole to gain further insight of the inhibition mechanism.
研究领域:
材料科学
·
电化学
·
理论计算
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Xiaohua Jing,Zhumei Sun,Dandan Zhao,Xiaoning Tang,Wenjing Lv,Yunfeng Shi
In this study, five novel ionic liquids denoted by [RNH 3 ][Cyanex 272] where R = C 4 H 9 , C 6 H 13 , C 8 H 17 , C 10 H 21, and C 12 H 25 were synthesized in a one-step reaction of straight-chain primary amines and Cyanex 272. The singe-stage extraction performance of [RNH 3 ][Cyanex 272] for the separation of Mn 2+ , Co 2+ , Ni 2+ and Li + was investigated. Compared with the other [RNH 3 ][Cyanex 272], the [C 4 H 9 NH 3 ][Cyanex 272] has good selective extraction and separation of Mn 2+ , Co 2+ , and Ni 2+ due to the smaller different value between the radius of metal ion and the radius of [C 4 H 9 NH 3 ] + . Using a three-stage cross flow extraction, the extraction percentages of Mn 2+ , Co 2+ , Ni 2+ , and Li + were about 99.4, 99.1, 14.9 and 0.9 %. The [C 4 H 9 NH 3 ][Cyanex 272] is a good extraction agent for co-extraction of Mn 2+ , Co 2+ , and a part of Ni 2+ from Li + based on a three-stage cross flow extraction. Diluted sulfuric acid was used to strip the organic phase containing Mn 2+ , Co 2+ , and Ni 2+ , and the aqueous phase containing Mn 2+ , Co 2+ , and Ni 2+ can be used for the preparation of ternary precursor materials. The precipitation method can be used to prepare Ni(OH) 2 and Li 2 CO 3 from an aqueous phase containing Ni 2+ and Li + . The conceptual recycling flow-sheet for Mn 2+ , Co 2+ , Ni 2+ , and Li + from spent ternary lithium batteries was presented on basis of the new extraction agent. The slope method was also used to investigate the mechanism of the extractive reaction of Mn 2+ , Co 2+ , and Ni 2+ using the [C 4 H 9 NH 3 ][Cyanex 272].
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2024
·
IF 2.9
Fuge Niu,Xinyu Hu,Christos Ritzoulis,Weiwei Tu,Xurui Zhao,Yuanzhi Xia,Yinghua Lu,Junfeng Yin,Weichun Pan
The formation of aggregates was studied in amino acid aqueous solutions. Regarding to arginine (Arg), the main driving force to form aggregates is hydrogen-bonds between the Arg molecules. The measurement of energy loss during this process, coupled with morphology data indicate that this aggregate is in solid state. The aggregation has two steps, with a liquid intermediate stage. An investigation of the effect of pH and solute concentration upon aggregate formation for other amino acid aqueous solutions verifies that aggregate formation is amino-acid specific, while small size of clusters formed by weak interactions lead to large size aggregation. Homochirality is observed in the aggregates; its existence sheds light on the origin of protein homochirality.
研究领域:
生物化学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）