SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Xuanbing Wang,Junli Wang,Wenhao Jiang,Chen Chen,Bohao Yu,Ruidong Xu
In industrial zinc electrowinning, the anodic oxygen evolution reaction (OER) has sluggish kinetics leading to ultrahigh overpotential and energy consumption. Herein, a sandwich-like MnCo 2 O 4 modifying PbO 2 composite electrode was fabricated via chemical-bath-deposition and electrodeposition. Consequently, the synthesized PbO 2 electrode exhibits low Tafel slope of 0.17 V per decade and an operating potential of 1.68 V vs. SCE for 500 A m −2 in a simulated solution containing 150 g L −1 H 2 SO 4 and 50 g L −1 Zn 2+ . Compared with traditional Pb-0.76Ag alloy, the overpotential at 500 A m −2 decreased by 357 mV, which ascribe to the incorporation of MnCo 2 O 4 minoring crystal grain size and charge transfer resistance and enlarging active surface area. Furthermore, the composite electrode shows robust durability as long as 95 h at 15,000 A m −2 in 0.5 M H 2 SO 4 electrolyte. Hence, this study offers a facile synthesis route to prepare composite electrodes for zinc electrowinning and provides deep insight into the relationship among modifying substances, microstructures, and electrocatalytic activity.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Jianqiang Ye,Buming Chen,Shixing Wang
The zinc electrowinning process demands considerable energy, prompting the quest for energy-efficient solutions to curtail costs. Hence, the development of energy-saving anode materials for zinc hydrometallurgy is an important issue. Herein, multilayered PbO 2 film materials were prepared through thermal decomposition and composite electrodeposition, yielding a new PbO 2 –ZrO 2 electrode featuring ZrO 2 particles as the second phase for energy-saving zinc electrowinning. The introduction of ZrO 2 leads to reduced PbO 2 crystal size, heightened the specific surface area of the electrode, and preferential growth of crystal planes. Electrochemical tests underscore that the PbO 2 –ZrO 2 electrode manifests a reduced charge-transfer resistance ( R ct ) and overpotential alongside a 46.15 % extension in service life compared to the pure PbO 2 electrode. Simulated zinc electrowinning experiment affirms PbO 2 –ZrO 2 electrode has a 3.63 % surge in the current efficiency and a substantial 244.61 kWh/t reduction in energy consumption relative to the traditional Pb–0.6wt%Ag anode. This study provides a strategic framework for designing and developing cost-efficient, cost-effective anode materials, promoting advancements in energy conservation and consumption reduction within zinc electrowinning processes.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Zuowei Liu,Qinghua Tian,Xueyi Guo,Yasong Huang,Zhipeng Xu
Traditional gallium electrowinning suffers from low current efficiency and high specific energy consumption due to the inevitable hydrogen evolution reaction. In order to inhibit hydrogen evolution reaction and alleviate the concentration polarization, the pulse cyclone electrowinning process was proposed and developed to enhance diffusion and convection. During the pulse current off time, the ion concentration in the cathode diffusion layer can be effectively restored, while forced convection accelerates this process. Electrochemical experiments using a rotating disk electrode have preliminarily confirmed that pulsed electrodeposition can accelerate nucleation and improve current efficiency. Pilot experiments were conducted using an industrial gallium electrolyte to further validate the feasibility of the pulse cyclone electrowinning process. Under the following conditions: current density of 2000 A/m 2 , duty ratio of 50%, frequency of 10 Hz, and circulation flow of 400 L/h, the current efficiency and specific energy consumption were determined to be 69.21% and 7836 kWh/t, respectively. Compared to the traditional electrowinning process at the same average current density, pulse cyclone electrowinning exhibited a significant increase in current efficiency and a reduction in specific energy consumption by 52.28% and 31.57%, respectively. Overall, this study confirmed the feasibility of pulse cyclone electrowinning coupling pulse current and forced convection, which can also be applied to other electrodeposition processes to achieve higher current efficiency and lower energy consumption.
研究领域:
冶金工程
·
电化学工程
✓ 已验证
产品关联
DOI
高影响因子
HYDROMETALLURGY
·
2020
·
IF 3.338
Xuanbing Wang,Ruidong Xu,Suyang Feng,Chen Chen,Buming Chen
In this paper, a Co 3 O 4 - and CNT-doped 3D PbO 2 electrode was fabricated through galvanostatic electrodeposition in a Pb(Ac) 2 -NH 2 SO 3 H solution, and the electrochemical properties were systematically investigated in a zinc electrolyte. The XRD results show that the deposit is a mixture of an α + β phase (a dominant β-PbO 2 phase with a minor α-PbO 2 phase present), and the SEM images show that Co 3 O 4 and CNT have been simultaneously deposited with PbO 2 . The 3D-Ti/PbO 2 -(4 g·L −1 ) Co 3 O 4 -(0.4 g·L −1 ) CNT electrode exhibits a voltammetric charge 5 times larger than that of the 3D-Ti/PbO 2 electrode, which indicates outstanding electrocatalytic activity. The oxygen evolution reaction overpotential and cell voltage are only 394 mV and 3.74 V at 500 A∙m −2 , respectively. In addition, the obtained electrode showed a high current efficiency of 95.3% and a service life of 26 h under a current density of 20,000 A∙m −2 . Hence, this study offers a facial synthesis route to prepare composite electrodes for zinc electrowinning and provides deep insight into the relationship among doping substances, microstructures and electrocatalytic activity.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Sustainable Metallurgy
·
2021
·Vol. 7
·期 4
·1910-1916
·
IF 2.347
Li You-gang,Liu Shan-shan,Wang Chang-hong,Luo Tao,Xiang Chang-liu,Li Shuai,Chang Cong,Yang Sheng-hai,Wang Heng-hui,Chen Yong-ming
The lead (Pb) electro-refining in the green methanesulfonic acid (MSA) system presents an alternative route to the conventional fluosilicic-acid-based Pb electro-refining. Herein, we investigated the electro-deposition behavior of the MSA-based Pb electro-refining by electrochemical measurement and apparent characterization techniques. The operational principle of the Pb deposition was preliminarily understood by performing cyclic voltammetry (CV) complemented with SEM–EDS detection. The results indicated the thermodynamic priority of the efficient Pb 2+ /Pb reduction reaction over the H + /H 2 one. The impact of various factors such as MSA concentration, scanning rate, and temperature on the effectiveness of Pb electro-deposition were investigated by linear sweep voltammetry and electrochemical impedance spectroscopy. Further numeric calculation and model analysis helped acquire in-depth kinetics and mechanism knowledge, such as the discharge form of divalent Pb(II), reversibility of the electrode process, apparent activation energy, reaction order and deposition reaction kinetics. Overall, this work revealed important electrochemical mechanism, principle, and kinetics of the Pb deposition in the MSA-based electro-refining process and would offer a significant guidance in condition optimization of its practice. Graphical Abstract
研究领域:
电化学
·
冶金工程
·
材料科学
·
绿色化学
·
应用化学
✓ 已验证
DOI
高影响因子
HYDROMETALLURGY
·
2020
·
IF 3.338
Shiwei He,Ruidong Xu,Li Sun,Youqi Fan,Zhuo Zhao,Huan Liu,Huihong Lv
In this study, a new anode based on Pb-0.3%Ag/α-PbO 2 /β-PbO 2 -Co 3 O 4 composite is proposed and its performance is compared with that of the traditional Pb-1wt%Ag anode during long-term zinc electrowinning . The electrocatalytic activity of the new anode for the oxygen evolution reaction (OER) initially decreased and then gradually increased, which was attributed to the phase transition occurring at the surface of the anode, and its corrosion resistance was gradually improved with the progress of electrowinning. Further, the electrochemical characteristics, cell voltage , current efficiency , and energy consumption of the two anodes were evaluated after 16 days of electrowinning. The OER electrocatalytic activity and corrosion resistance of the new anode were observed to be higher than those of the traditional anode. In addition, the cell voltage and power consumption of the new anode were significantly lower than those of the traditional anode. Furthermore, compared to the traditional anode, the energy consumption for producing 1 t of zinc was reduced by 358.13 kWh based on the new anode.
研究领域:
电化学
·
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2020
·
IF 3.807
Kui Liu,Yufeng Gao,Zhengyan Fang,Xiangyu Zhou,Yue Ma,Hanyu Wu,Mingliang Kang,Biao Wang
In the electrowinning or chemical reductive extraction process, those mass transfer kinetic parameters , for instance the diffusion coefficient in the liquid cathode or medium, have a strong impact upon the practical extraction rate and separation efficiency. This work aims to calculate the diffusion coefficient of uranium in liquid gallium with galvanostatic intermittent titration technique (GITT) and to deduce its corresponding activation energy . By analyzing the data of GITT, before U saturation in liquid gallium at the temperature range of 673-873 K, the temperature dependence of diffusion coefficients of uranium in liquid gallium was measured as ln D U Ga = − 6.90 ± 1.03 − 1.2 ± 0.8 × 10 3 T and the corresponding activation energy was determined as E a = −11.0 ± 6.7 kJ/mol. The possible source of errors to calculate the diffusion coefficients, such as reference electrode, small solubility of uranium in gallium, side reactions and geometrical approximation of cathode in the theory formula are also presented and discussed.
研究领域:
材料科学
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化工工程
·
核工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Tianyang Liu,Junli Wang,Xuanbing Wang,Jinlong Wei,Xiaoning Tong,Shengyou Su,Ju Zhang,Yuantao Yang,Ruidong Xu,Linjing Yang
The traditional Pb-Ag anodes used in zinc electrowinning exhibit high overpotential for oxygen evolution reaction (OER) and poor mechanical strength, leading to high energy consumption. To overcome the shortcomings, Ti/SnO 2 -Sb 2 O 4 /PbO 2 -La-doped MnCo 2 O 4.5 composite anode was prepared by this work. It demonstrated enhanced electrochemical performance, requiring 565 mV to reach the benchmark current density of 50 mA cm −2 , and the Tafel slop of 179.79 mV dec –1 in the acidic media containing 50 g L –1 Zn 2+ and 150 g L –1 H 2 SO 4 . According to the results of XPS, the content of Mn 4+ and Co 3+ increased, which was beneficial to promote the OER catalytic activity of the electrode. The current efficiency was improved by 1.7 % compared with traditional Pb-0.76 % Ag anode, resulting in a significant reduction in energy consumption of 477.46 kW∙h for producing one ton of zinc. Moreover, the Ti/SnO 2 -Sb 2 O 4 /PbO 2 -La-doped MnCo 2 O 4.5 anode showed excellent corrosion resistance, and the accelerated service time was extended to 50 h at 2 A cm −2 . The service life of the electrode was extended thanks to the introduction of the intermediate layer and La-doped MnCo 2 O 4.5 powder. Therefore, this work provided a novel strategy to prepare the anodes with enhanced electrochemical performance applied in zinc electrowinning and other aspects.
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
Nanomaterials
·
2024
·Vol. 14
·期 1
·126
·
IF 4.4
Xuchao Pan,Libo Zhang,Jialu Guan,Jing Lv,Yifei Xie,Haifeng Yang,Linghua Tan
Electrostatic accumulation is associated with almost all powder-conveying processes which could bring about electrostatic discharges. In most cases of industrial accidents, electrostatic discharge is proven to be the primary source of ignition and explosion. Herein, a surface modification process of polyaniline (PANI) is proposed to construct highly exothermic special powders, namely, HMX@PANI energetic composites, with low charge accumulation for improving powder electrostatic safety. Pure HMX are encapsulated within the PANI-conductive polymer layer through simple hydrogen bonding. Simulation results demonstrate that the forming process of HMX/aniline structure is a spontaneously thermodynamical process. The resultant inclusion complex exhibits excellent thermal stability, remarkable compatibility and intensive heat release. Importantly, PANI possesses superior electrostatic mobility characteristics because of the π-conjugated ligand, which can significantly reduce the accumulated charges on the surface of energetic powders. Moreover, the modified explosive has a narrower energy gap, which will improve the electron transition by reducing the energy barrier. The electrostatic accumulation test demonstrates that HMX@PANI composites possess a trace electrostatic accumulation of 34 nC/kg, which is two orders of magnitude lower than that of pure HMX (−6600 nC/kg) and might indicate a higher electrostatic safety. In conclusion, this surface modification process shows great promise for potential applications and could be extensively used in the establishment of high electrostatic safety for special powders.Keywords:electrostatic accumulation;surface modification strategy;conductive polymer;energetic materials;special powders;thermal stability
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Zhaohui Han,Lei Xu,Chandrasekar Srinivasa Kannan,Jianhua Liu,Sivasankar Koppala,Shaohua Ju,Libo Zhang
In this paper, an Al/TiB 2 layered composite was prepared by plasma spraying for use as the base material to reduce resistivity and improve electrochemical performance in an electrode. The β-PbO 2 coating was prepared by electrochemical deposition . Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to study the Al/TiB 2 composite and the β-PbO 2 coating. The electrochemical performance of the Al/TiB 2 /β-PbO 2 and Ti/β-PbO 2 composites was studied by linear sweep voltammetry (LSV), Tafel polarization curves (Tafel) and electrochemical impedance spectroscopy (EIS). The results indicate that Al/TiB 2 /β-PbO 2 composite electrode materials with a uniform structure were successfully prepared by plasma spraying and electrochemical deposition. The structure of the Al/TiB 2 composite improves the conductivity of the electrode matrix, the optimal value of conductivity is 2.76 × 10 7 S m −1 , and the optimal value of density is 8.758 g cm −3 for β-PbO 2 coating. The composite also decreases the charge resistance in the double layer structure of the electrode surface, accelerating the charge transfer rate. Compared with the Ti matrix, the Al/TiB 2 /β-PbO 2 exhibited the best corrosion-resistant performance and electrochemical catalytic activity for electrowinning of nonferrous metals .
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
FUEL
·
2025
·
IF 7.5
Penglin Kang,Changgui Song,Jinbo Guo,Yuan Lai,Xiangru Li,Leixin Hou,Wenjie Liu,Xiaodong Li
To achieve a synergistic enhancement of both energy output and safety performance in metal powder-based high-energy materials, this study employed coaxial focusing droplet technology to fabricate HMX/TiH 2 /F composite microspheres. The influence of dispersed phase concentration on microsphere morphology and particle size was systematically investigated. HMX/F and HMX/Ti/F microspheres, prepared using the same method, served as control groups for analyzing crystal structure and functional group composition. Results indicated that all three types of microspheres retained their original chemical structures. Performance tests revealed that HMX/TiH 2 /F microspheres achieved a favorable balance between thermal stability and reactivity, with thermal safety significantly improved compared to the control samples. Specifically, its impact sensitivity increased by 8 J and 13 J compared to HMX/F and HMX/Ti/F, respectively; friction sensitivity increased by 164 N and 228 N; and electrostatic accumulation was reduced by 1.46 and 16.40 nC, respectively, demonstrating superior mechanical and electrostatic safety. Combustion and detonation tests further demonstrated that HMX/TiH 2 /F microspheres exhibited the most intense combustion flame. The ignition delay time was reduced by 67.48 ms and 26.20 ms compared to HMX/F and HMX/Ti/F, respectively, and the combustion duration was shortened by 0.51 s and 0.42 s. Meanwhile, HMX/TiH 2 /F composite microspheres still maintained a high energy output, and the measured detonation velocity was 7685.7 m/s, which was 149.99 m/s higher than that of HMX/Ti/F. These findings indicate that the incorporation of TiH 2 facilitates the coordinated optimization of high-energy materials with respect to both safety and energetic performance, demonstrating promising application potential.
研究领域:
材料科学
·
含能材料
·
热力学
·
燃烧学
·
安全工程
·
颗粒工程
✓ 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）