JOURNAL OF RARE EARTHS
·
2024
·
IF 5.2
Yusufujiang Mubula,Mingming Yu,Hongju Gu,Lei Wang,Man Chen,Tingsheng Qiu,Guangjun Mei
Rare earth molten salt electrolytic slag (RMES) has emerged as a promising secondary resource for rare earth elements (REEs). This study introduces an innovative leaching technique for extracting REEs from RMES under atmospheric conditions, employing an alkali phase reconstruction method followed by an acid leaching process. Additionally, the external electric field was employed to enhance the reaction. Under the optimal reaction conditions: NaOH initial concentration of 70 wt%, NaOH-slag mass ratio of 4:1, temperature of 160 °C, current density of 1000 A/m 2 , reaction time of 90 min, stirring speed of 300 r/min, HCl concentration of 4 mol/L, liquid-solid ratio of 15:1, and leaching time of 20 min, the leaching efficiencies of Nd and Pr reach up to 99.21% and 99.14%, respectively. Phase analysis indicates that the rare earth fluorides transform into rare earth hydroxides, significantly enhancing their solubility in acid solution. The imposition of an external electric field leads to pronounced disruption of the RMES surface, thereby promoting the formation of stable reactive oxygen species in the alkaline medium. This facilitates the decomposition of fluorinated rare earths and hastens the phase reconstruction, resulting in an enhanced leaching process. The achieved leaching efficiency with an external electric field is 37% higher than that without an electric field.
研究领域:
冶金工程
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Zhongsheng Hua,Xiaobin Wu,Zengli Zhu,Jiwen He,Shiwei He,Huan Liu,Liang Xu,Yongxiang Yang,Zhuo Zhao
Exploring more efficient and low-cost electrocatalysts to replace platinum (Pt) is highly desired to promote the practical hydrogen production through water splitting. Herein, a facile and effective strategy is proposed to fabricate self-standing Al 3 Ni 2 /Ni electrode with controlled phase composition and surface morphology, which is obtained by one-step electrochemical reduction of Al 3+ on commercially available nickel in eutectic NaCl-KCl melt. Different from previously reported approaches, uniform Al 3 Ni 2 monolith catalyst can directly grow onto Ni substrate. The deposit possesses unique three-dimensional (3D) cauliflower-like morphology comprising of nano- and microparticles due to the rapid nucleation rate during molten salt electrolysis. The as-fabricated Al 3 Ni 2 /Ni electrode can be directly used as the cathode to catalyze Hydrogen evolution reaction (HER). Impressively, it exhibits remarkable HER activity comparable to commercial Pt, including a low overpotential of 83.4 mV for a current density of 10 mA cm −2 , a small Tafel slope of 40.7 mV dec -1 , and excellent long-term stability over 36 h of continuous HER operation in 0.5 M H 2 SO 4 solution. The intrinsic catalytic ability of Al 3 Ni 2 with the unique hierarchical structure of nano/microsized grains can offer multiple effects, including massive exposed active sites, enhanced charge transfer and mass transport, and fast gas releasing that synergistically contribute to improving the electrocatalytic performance of HER. This work represents a highly promising approach to the design and one-step controllable fabrication of efficient and self-standing base metal electrode for electrocatalytic hydrogen production.
研究领域:
材料科学
·
电化学
·
能源科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Shijie Li,Qi Wang,Yao Chang,Zhenghao Pu,Yi Lu,Yiwa Luo,Zhe Wang,Wei-Li Song,Wei Wang,Shuqiang Jiao,Dongbai Sun
The molten salt electrolysis method has garnered significant attention for titanium extraction. However, the multi-step reduction and disproportionation reactions of titanium ions severely impact the current efficiency of this process. This study investigated the cathodic behavior of titanium ions on liquid lead (Pb) and zinc (Zn) electrodes in fluoride melts using first-principles calculations and electrochemical analysis. The structure of titanium species in the melt and the reduction mechanism of titanium ions on solid molybdenum (Mo), liquid Zn, and Pb electrodes were elucidated through high-temperature in-situ Raman spectroscopy and experimental analysis. Numerical simulations were employed to analyze the electrolysis process, yielding optimal electrolysis parameters such as current density and overpotential. Electrolysis products were examined through experimental electrolysis and X-ray computer microtomography (x-ray μ-CT) reconstruction, validating the numerical simulation results and confirming the optimal electrolysis parameters. These findings provide valuable insights for enhancing the scalability of the molten salt electrolysis method for titanium extraction and purification.
研究领域:
材料科学
·
电化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2015
·Vol. 163
·期 3
·E33
·
IF 3.266
Liwen Hu,Yang Song,Jianbang Ge,Shuqiang Jiao,Jin Cheng
Molten CaCl2 has been considered as significant electrolyte for novel electrochemical metallurgy processes due to high solubility of oxygen anions. Some novel processes based on molten-salt electrolysis of oxides in molten chlorides have been proposed, typically including FFC process and OS process. An inert anode capable of sustained oxygen evolution is crucial for a green and efficient electrochemical de-oxidation process. Herein we report the results of a promising inert anode candidate, who shows an excellent performance. Several techniques including anodic polarization, cyclic voltammetry, Tafel polarization and electrochemical impedance have been performed to evaluate the anode behavior of the TiO2·RuO2 anode, revealing that the anode is quite stable during anodic polarization and has a more positive corrosion electrode potential. An in situ analysis of anode gases using the mass spectra proved the capability of the sustained evolution of oxygen at the TiO2·RuO2 anode during electrolysis, meaning that this oxides anode could be a potential candidate as inert anode in calcium chloride–calcium oxide melts for green metallurgical processes, as it showed a nearly negligible solubility of ruthenium dioxide when immersed in the melt and a low rate of corrosion even after long time electrolysis.
研究领域:
冶金学
·
电化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Liyu Chen,Jiaxin Yang,Yifan Zhang,Shaohua Wu,Youjian Yang,Wenju Tao,Zhaowen Wang
The synthesis of an Al–Zr master alloy in KF–AlF 3 –ZrO 2 molten salt by combining aluminothermic reduction and molten salt electrolysis processes was studied. The effects of reduction parameters such as stirring, reaction time, Al/ZrO 2 mass ratio and temperature on the Zr content and Zr recovery rate were studied and optimized. Under the optimal conditions of stirring, reaction time of 4 h, Al/ZrO 2 mass ratio of 3 and temperature of 960 °C, an Al–Zr master alloy can be obtained with a Zr content of 6.78 wt% and Zr recovery rate of 29.85%. The characterization results of the alloy show that the main phases contain Al and Al 3 Zr. And the Al 3 Zr appears as long rod-shaped or tetragonal shapes, which influenced by the Zr content and cooling rate. In addition, the reduced molten salt is electrolyzed to further extract Zr from the molten salt. The results show that the Zr remaining in the molten salt is completely recovered with a Zr recovery rate up to 94.72%. This two-step process is feasible for the large-scale extraction of Zr in molten salts to produce Al–Zr master alloys.
研究领域:
冶金工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2023
·Vol. 170
·期 8
·082502
·
IF 3.9
Ruijing Kong,Shanshan Liu,Zepeng Lv,Shaolong Li,Yong Fan,Jilin He,Handong Jiao,Jianxun Song
In electrochemical process, electrolyte composition is one of the key factors that determine the electrochemical behavior of elements. In this work, the nucleation mechanism and deposition process of titanium ions after the introduction of fluoride ions into molten salt were analyzed in detail by electrochemical technology, and the coordination behavior between fluorine ions and titanium was explored by molecular dynamics simulation, revealing the relationship between the electrocrystallization mechanism of titanium and its coordination properties. It can be found that the electrocrystallization mechanism of titanium ions is related to its coordination structure. Under our experimental conditions, the Ti-Cl bond in the system was gradually replaced by the Ti-F bond. This will lead to the change of charge transfer and ion diffusion of titanium ions, which will have an important effect on the electrocrystallization processes. This work has an important guiding significance for further study on the influence of different molten salt systems on the electrocrystallization mechanism of molten salt electrolytic titanium.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 8
·083501
·
IF 4.316
Peng Wang,Yanan Liu,Zhida Li,Deqiang Ji,Zhiqiang Qiao,Jing Zhang,Qinxin Jia,Hongjun Wu
Molten salt electrochemistry is cited as one of the most efficient ways to convert stable but unwanted CO2 into value-added chemical fuels and functional materials, in particular carbon nanotubes (CNTs). In this work, we report the high yield and scalable CO2-deriving CNTs by adding ZnO to molten carbonate electrolyte. The physicochemical properties such as crystal structure, morphology and element composition of the carbon products were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), X-ray diffractometer (XRD) and Raman spectrometer (Raman). It is demonstrated that an appropriate amount of ZnO additives can greatly increase the content of CNTs in carbon products. However, the micromorphology and microstructure of the carbon products are found to be significantly changed when the ZnO content is insufficient or excessive. Compared with molten salt electrolyte without ZnO, ZnO-included electrolyte endows CNTs with a higher degree of graphitization and crystallinity. This work demonstrates the feasibility of improving CNTs content in carbon products and lowering required energy for CNTs production by adding ZnO as a promoter.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Xuan Liu,Hao Guo,Jilai Xue,Zengjie Wang,Yanan Zhang,Xiang Li
Al-7Si-0.8Sc-0.6Ce alloys were prepared with combined addition of low-cost Ce and high-priced Sc through molten salt electrolysis with controlled cooling process. The phases of as-casted alloys consisted of α-Al, eutectic silicon , ternary AlSi 2 Sc 2 and CeAl 2 Si 2 . Rapid cooling transformed the huge hollow ternary AlSi 2 Sc 2 blocks (300–500 µm) into fine Al 3 Sc particles (dozens of μm), and simultaneously refined the AlSi 2 Sc 2 with reducing its interlayer thickness from 15.26 µm down to 1.94 µm (the cooling rate from 0.05 K s −1 up to 30 K s −1 ). The eutectic Si became fine fibrous-like clusters and the thickness of CeAl 2 Si 2 phase reduced by 62.6 % when the cooling rate reached 30 K s −1 . Micro-hardness measurement and first principles-based calculation were applied for evaluating the individual mechanical performance of each phase in the alloy. The calculated Young’s modulus (E) suggests that Al 3 Sc (E = 168 GPa), AlSi 2 Sc 2 (E = 178 GPa) and CeAl 2 Si 2 (E = 39.2 GPa) can toughen Al-matrix (E = 30.6 GPa). The rapid cooling (30 K s −1 ) strongly enhances all phase components but diminish the huge hollow AlSi 2 Sc 2 blocks (ultrahigh micro-Vickers hardness ∼ 780 HV), making a homogenous Al-RE alloy with improved mechanical property (68 ∼ 84 HV balanced among phase components). The refining mechanisms on the improved mechanical performance are also discussed.
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2019
·Vol. 166
·期 13
·E401
·
IF 3.12
Handong Jiao,Shuqiang Jiao,Wei-Li Song,Haosen Chen,Mingyong Wang,Jiguo Tu,Daining Fang
Owing to the low-cost and fast process, molten salt electrolysis is considered as a novel method to replace the Kroll process for preparing titanium. However, this process has not been fully realized because of the multi-step reduction and complicated disproportionation behaviors of multivalent titanium ions in melt. To address such critical problems, here we use liquid metals (Sn and Pb) as the cathode instead of solid metal cathode (Mo) during the electrolysis, in which the reduction process of Ti3+ (TiF63−) becomes a simple one-step process (Ti3+ + 3e = Ti (alloys)). Also, the deposition potential is more positive (>0.5 V) than that using solid Mo, owing to the depolarizing effect of the liquid metals. One-step process and depolarization behavior are favorable to increase the current efficiency, effectively decreasing the power consumption in comparison with the conventional electrolysis at solid metal cathodes. Similar to the electrolytic production of aluminum in Hall-Heroult system, there would be a continuous electrolysis process because the product is liquid alloy in this system.
研究领域:
材料科学
·
电化学工程
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2018
·Vol. 11
·期 11
·1880-1886
·
IF 7.411
Cheng Peng,Chengzhi Guan,Jun Lin,Shiyu Zhang,Hongliang Bao,Yu Wang,Guoping Xiao,George Zheng Chen,Jian-Qiang Wang
Graphical Fe-clad results : A low-cost, high-temperature rechargeable iron–oxygen battery containing a bi-phase electrolyte of molten carbonate and solid oxide is described. This new design merges the merits of a solid–oxide fuel cell and molten metal–air battery, offering significantly improved battery reaction kinetics and power capability without compromising the energy capacity. The energy and power density of conventional batteries are far lower than their theoretical expectations, primarily because of slow reaction kinetics that are often observed under ambient conditions. Here we describe a low-cost and high-temperature rechargeable iron–oxygen battery containing a bi-phase electrolyte of molten carbonate and solid oxide. This new design merges the merits of a solid–oxide fuel cell and molten metal–air battery, offering significantly improved battery reaction kinetics and power capability without compromising the energy capacity. The as-fabricated battery prototype can be charged at high current density, and exhibits excellent stability and security in the highly charged state. It typically exhibits specific energy, specific power, energy density, and power density of 129.1 Wh kg −1 , 2.8 kW kg −1 , 388.1 Wh L −1 , and 21.0 kW L −1 , respectively, based on the mass and volume of the molten salt.
研究领域:
能源材料
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Jinzhao Guan,Kaiyu Xie,Aimin Liu,Zhongning Shi,Gong Chen,Miroslav Boca
In this study, Al–Si alloy, a precursor of the solar-grade silicon , was prepared via the aluminothermic reduction–molten salt electrolysis of SiO 2 in KF–AlF 3 molten salt by employing liquid aluminum as the working cathode. The reaction mechanism of the aluminothermic reduction of SiO 2 in KF–AlF 3 molten salt at 750 °C was determined by thermogravimetry–differential scanning calorimetry. The reaction rate equation for the aluminothermic reduction of SiO 2 in KF–AlF 3 molten salt was: d α dt = 7.156 × 10 24 e − 4.688 × 10 5 RT ( 1 − α ) 1.734 . In 49.4 wt% KF–47.6 wt% AlF 3 –3 wt% SiO 2 molten salt at 750 °C, the Si content in the Al–Si alloy obtained by the aluminothermic reduction–molten salt electrolysis of SiO 2 was 24.53 wt%. Compared with solely aluminothermic reduction of SiO 2 , the current efficiency in the process of the aluminothermic reduction–molten salt electrolysis of SiO 2 was evaluated. The results reveal that the Al–Si alloy is predominantly prepared in the aluminothermic reduction step, while supplemented by electrolysis. The calculated Faradic current efficiency of the proposed aluminothermic reduction–molten salt electrolysis process was 28.4%.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2018
·
IF 3.398
Ming Li,Xiaoli Xi,Zuoren Nie,Liwen Ma,Qingqing Liu
The recycling of WC–Co hard metal scraps has been taken into consideration in the literature, due to the release of toxic substances and long recovery process. In this study, the recovery of tungsten process, based on the molten salt electrolysis treatment of WC–Co hard metal scraps, was developed. The anode polarization curves were applied to investigate the dissolution of the WC–Co hard metal scrap. Then, the electrochemical behavior of tungsten and cobalt ions dissolved from WC–Co scrap anode, was studied by cyclic voltammetry (CV) and square wave voltammetry (SWV). The results demonstrated that the reduction of tungsten and cobalt ions occurred through a one-step process involving the transfer of two electrons. This process was achieved by the diffusion of tungsten and cobalt ions in the melts. Finally, the parameters, such as the electrolysis current, the electrolysis duration and temperatures, were applied to analyze the effect of different electrolysis conditions on the composition of recycled products. The results demonstrated that the electrolysis current and the electrolysis temperature, compared to electrolysis duration, have significant effects on the selectivity of tungsten recycling. Furthermore, the analysis of cathode products demonstrated that a tungsten powder of approximately 500 nm could be selectively recovered from WC–Co hard metal scrap with the electrolysis condition of 60 mA for 4 h at 1073 K in NaF–KF molten salt.
研究领域:
材料科学
·
环境工程
✓ 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）