ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Handong Jiao,Mengjun Liu,Zhe Wang,Manpeng Lin,Zhaoliang Qu,Jianxun Song,Shuqiang Jiao
Molten salt electrorefining is expected to be a powerful technology for upcycling titanium scrap because of its robust ability of removing impurities. However, realizing the stable operation of electrorefining, for example, the current efficiency of the anode and the cathode is still a key challenge from the viewpoint of industrial applications. Here, we study titanium’s anodic dissolution and cathodic deposition processes via a direct three-dimensional visualization method based on a computed tomography technology under high-temperature operational conditions. Real-time quantitative results show that the current efficiency is obviously affected by the concentration of titanium ions in the melt. Visual analysis of the local dissolution rate and the curvature of the titanium anode at different electrolysis stages reveals the kinetic origin of the concentration-induced current efficiency changes, which arise from the priority of the side reactions being dependent on the concentration of titanium ions. Finally, we show that employing the high concentration and single existence forms of titanium ions is an effective strategy to prevent the side reactions and improve the current efficiency. This work provides a fresh and fundamental understanding of the side reactions occurring at the interface of electrodes and is significant for facilitating the stability of electrorefining engineering of titanium.
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 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
MATERIALS TRANSACTIONS
·
2017
·Vol. 58
·期 3
·395-399
·
IF 0.713
Xiaolong Liu,Chao Huang,Bing Li
In this paper, the cyclic voltammetry was applied to investigate the electrochemical reduction processes of Nd(III) ions in NdF3-LiF melts with or without excessive metal Nd. Equilibrium experiments were carried out in NdF3-LiF melts with excessive spheric metal Nd to investigate the relationship between the NdF3:LiF mass ratio and NdF2 concentration. Electrolysis experiments were performed in NdF3-LiF-Nd2O3 melts with different NdF3:LiF mass ratios to explore the relationship between the NdF2 concentration and the current efficiency.The results indicated that Nd(III) ions in the melts were reduced in two steps, i.e., Nd(III)→Nd(II) and Nd(II)→Nd(0). NdF2 could be formed by the comproportionation reaction between Nd(III) and Nd(0) and could stably exist in NdF3-LiF melts containing metal Nd(0). NdF2 mass concentration in the melts decreased from 45.5% to 36.4% with the increase of NdF3-LiF mass ratio from 7:3 to 9:1 in NdF3-LiF melts containing excessive spheric metal Nd, which resulted in a higher current efficiency during the electrolysis. And the highest current efficiency of about 50% for Nd extraction has been obtained by electrolysis in NdF3-LiF (9:1 mass ratio) melts with Nd2O3 (2%, mass concentration) at 1423 K.
研究领域:
冶金学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2024
·
IF 6.9
Buju Guo,Yaowu Wang,Yuyao Huang,Jianping Peng,Yuezhong Di,Chang Wang,Ke Wang
The amount of scrap aluminum has increased continuously in recent years such that the widely adopted method of remelting no longer meets the demands of high-quality recycled secondary aluminum. Molten salt electrolysis is a method of upcycling scrap aluminum to pure aluminum. In this study, pure aluminum was recovered from scrap aluminum through the electrolysis of a 56 mol%LiCl-36 mol%KCl-8 mol%NaCl molten salt system. The electrochemical dissolution behavior of scrap aluminum was studied adopting an anodic polarization curve. The results show that Al dissolved preferentially compared with Si and Fe in scrap aluminum. The effects of electrolysis parameters, such as the AlCl 3 concentration, electrolysis temperature, and current density, on the current efficiency and cathode products were studied along with the process of purifying scrap aluminum. The results show that the adoption of a suitable current density, electrolysis temperature and AlCl 3 concentration increases the current efficiency and improves the morphology of the cathode products. Pure aluminum of industrial grade with purity of 99.8 % can be obtained on the cathode at an electrolysis temperature of 550 °C, AlCl 3 concentration of 10 mol%, electrolysis time of 3 h, and current density controlled below 0.15 A/cm 2 .
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
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Changliu Xiang,Sijun Zhu,Jinbo Song,Yougang Li,Tao Luo,Cong Chang,Junjie Qu,Shenghai Yang,Changhong Wang,Yongming Chen
The conventional electrorefining process of crude lead (Pb)─employing a bone glue (BG)- and calcium lignosulfonate (CL)-synergistically assisted fluosilicic acid (H2SiF6) system─suffers the undesired environment burden caused by the high saturated vapor pressure and low stability of H2SiF6. Herein, we propose an additive-assisted methanesulfonic acid (MSA) system for green and efficient electrorefining of crude Pb based on the low volatility and high stability of MSA. Combinations of MSA with additives are evaluated and screened using photographic images, SEM observations, XRD, white light interference, etc. The electrochemical analysis of cyclic voltammetry and chronoamperometry elucidates the Pb deposition behavior in the Lugalvan BNO12-assisted MSA system, in which a three-dimensional nucleation model is applicable. Using MSA as the solvent and β-naphthol ethoxylate (Lugalvan BNO12) as the assisted additive, the bench-scale operation of crude Pb electrorefining experimentally achieves an electric energy requirement (W) of 87 kWhe/t Pb and a cathodic current efficiency (η) of 99.6%. This is very competitive with the W of 120 kWhe/t Pb and η of 95.0% for the BG-CL-assisted H2SiF6 system. Also, the bench-scale operation obtains a plat and dense deposit sample with a Pb purity of >99.99%. The distribution behavior of elements shows that most of the Pb element is recovered in the form of the cathodic Pb, elements Sn, Zn, and Fe mainly accumulate in the electrolyte, and elements As, Sb, Bi, Ag, and Cu remain in the anode slime. This work opens new directions for more technically and economically feasible Pb electrorefining.
研究领域:
冶金工程
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环境科学
✓ 已验证
DOI
高影响因子
JOM
·
2022
·Vol. 74
·期 5
·1889-1899
·
IF 2.597
Zhu Qiang,Yang Jianguang,Tang Chaobo,Nan Tianxiang,Ding Ruize,Liu Jiang
This work proposes a novel nitrogen bottom-blowing method to enhance mass transfer in the molten salt electrolysis process, improve current efficiency, and reduce electrolysis energy consumption. The effect of nitrogen agitation on the dissolution of Sb 2 S 3 and Sb was studied. The effects of nitrogen flow rate, electrolytic temperature, cell voltage, and pole spacing on the distribution behavior of Sb during constant piezoelectric reduction were investigated. The results show that nitrogen agitation can obviously accelerate the dissolution of Sb 2 S 3 . The current efficiency of the cathode reaches 92.76%, the energy consumption is 1.78 kWh kg −1 , and the grade of crude antimony is 98.5%. Compared to no nitrogen stirring, electrolytic current efficiency is improved by 19.87% and the energy consumption is saved by 20.89%. Furthermore, the appropriate flow rate of nitrogen accelerates the removal of sulfur from the reactor and avoids the formation of high-priced antimony compounds.
研究领域:
冶金学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
·
2024
·
IF 2.2
Yang Wenqiang,Han Shanyu,Yin Yakun,Wang Zelong,Shi Wen,An Juan,Wang Hongdan,Xia Wentang
The production of ultralight copper powder (UCP) remains challenging due to the requisite ultralow apparent density coupled with a well-developed dendritic morphology, which greatly constrain the modulation and optimization of process parameters. In this study, we conducted a comprehensive investigation to gain deeper insights into the impact of these parameters on the performance of deposited UCPs. Our findings revealed the limitations of relying solely on conventional electrolytic parameters for tailored UCP production. To overcome this challenge, the introduction of hydrochloric acid into the electrolyte system was proposed. Upon which, remarkable improvements in UCP production were observed, including optimized dendritic morphology, enhanced current efficiency and reduced power consumption. By adjusting the amount of chloride addition, UCPs with tunable particle sizes and apparent densities were obtained. Under the benchmark factory process condition, the chloride-treated UCP exhibited an ultralow apparent density (0.47 g cm −3 ) and particle size (19.96 μm), considerably surpassing the corresponding figures for industrial copper powder (1.79 g cm −3 and 64.10 μm) and even the optimum values achieved by GGP Metalpowder AG for their UCP products (0.55 g cm −3 and < 63 μm), with 22.5% of the particles exhibiting simultaneously ultralight and ultrafine properties.
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
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2024
·
IF 4.7
Zhi-peng XU,Zuo-wei LIU,Xue-yi GUO,Dong LI,Ming-jin ZOU,Qing-hua TIAN
A process for gallium recovery by cyclone electrowinning was proposed to inhibit concentration polarization and improve current efficiency (CE). The diffusion coefficient of GaO 2 − in 120 g/L NaOH solution was determined to be 1.65×10 −7 cm 2 /s by electrochemical study. The effect of various parameters on gallium electrowinning was investigated, and the optimum conditions were determined as: titanium cathode, current density of 750 A/m 2 , gallium concentration of 39.9 g/L, NaOH concentration of 120 g/L, and circulation flow of 200 L/h. Under these conditions, the CE and gallium recovery of electrowinning were 47.9% and 90.2%, respectively. The precipitated gallium can be easily separated from the cathode, and the final purity of gallium after washing was 99.993%. The energy consumption (EC) of gallium cyclone electrowinning was about 9048 kW·h/t. Overall, it is suggested that cyclone electrowinning is a promising process for gallium production with high CE and low EC.
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
·
2022
·Vol. 169
·期 6
·062504
·
IF 4.386
Fangzhao Pang,Peng Li,Zhuqing Zhao,Lei Guo,Kaifa Du,Bowen Deng,Dihua Wang,Huayi Yin
Electrolysis of solid oxides in molten CaCl2 has been proven a straightforward process to extract various metals thanks to the wide electrochemical window of CaCl2 and CaO which is soluble in molten CaCl2. However, the CaO produced during the cathodic reduction of oxides not only shuttles O2−, but also captures CO2 to generate CO32− that can be reduced to carbon at the cathode, resulting in decreasing current efficiency and contaminating the cathodic products by carbon. To solve this problem, we employed CaSiO3 to replace CaO to suppress/avoid the formation of CO32− and thereafter prevent the carbon deposition. The suppression of CO32− formation is because SiO32− is thermodynamically more stable than CO32−, i.e., the CO2 generated on the graphite anode can not be captured by SiO32−. In molten CaCl2−8.0 wt% CaSiO3, Cr2O3 and SiO2 are reduced to Cr and Si with much less carbon deposition than in molten CaCl2. As a result, the current efficiency increases from 21.4% to 51.9% for the reduction of Cr2O3 and 37.1% to 72.2% for the reduction of SiO2. Although introducing SiO32− will slightly decrease the electrochemical window of CaCl2, it will be a promising method to avoid carbon contamination and increase current efficiency especially for Si production.
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
Journal of Central South University
·
2024
·Vol. 31
·期 9
·3079-3089
·
IF 3.7
Jiang Yan-ying,Liu Ai-min,Tang Zi-rui,Lu Xiao-qing,Liu Feng-guo,Hu Xian-wei,Shi Zhong-ning
The electrochemical behavior of Al(III) in urea-1-butyl-3-methylimidazolium chloride-aluminum chloride (urea-BMIC-AlCl 3 ) ionic liquids, and the effect of potential and temperature on the characterization of cathode products, current efficiency and energy consumption of aluminum electrorefining have been investigated. Cyclic voltammetry showed that the electrochemical reduction of Al(III) was a one-step three-electron-transfer irreversible reaction, and the electrochemical reaction was controlled by diffusion. The diffusion coefficient of Al(III) in urea-BMIC-AlCl 3 ionic liquids at 313 K was 1.94×10 −7 cm 2 /s. The 7075 aluminum alloy was used as an anode for electrorefining, and the cathode products were analyzed by XRD, SEM and EDS. The results from XRD analysis indicated that the main phase of the cathode products was aluminum. The results from SEM and EDS characterization revealed that the cathode product obtained by electrorefining −1.2 V (vs. Al) was dense and uniform, and the mass fraction of aluminum decreased from 99.61% to 99.10% as the experimental temperature increased from 313 K to 333 K. In this work, the optimum experimental conditions were −1.2 V (vs. Al) and 313 K. At this time, the cathode current efficiency was 97.80%, while the energy consumption was 3.72 kW·h/kg.
研究领域:
材料科学
·
电化学
✓ 已验证
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2014
·
IF 2.235
Ying’hua Xu,Hai’feng Li,Cheng’pu Chu,Ping Huang,Chun’an Ma
A carbon felt was used as the cathode material for the indirect electrochemical reduction of indigo in alkaline aqueous solution employing iron-triethanolamine (Fe-TEA) complex as a redox mediator. Surface structure and specific surface area of the carbon felt electrode and its electrochemical performance toward the reduction of indigo were investigated by SEM, BET, and cyclic voltammetry, respectively. Moreover, an optimization of different operating conditions for the reduction of indigo was performed with an H-cell. In particular, the dependence of current efficiency (CE) on electrolysis time was chosen to analyze the indirect electrochemical reduction mechanism of indigo. The results showed that the carbon felt, having a high specific surface area of approximately 7289 cm2·g–1, is an excellent electrode material for the indirect electrochemical reduction of indigo and that a moderate current density, temperature, and concentration of indigo has the most beneficial effects on the reduction process.
研究领域:
环境科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）