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Electrolytic manganese is an important metal material that is widely employed in batteries, electronics, steel, and other fields. However, there are many issues regarding the production process of electrolytic manganese, such as low current efficiency, high-content toxic SeO2 additives in the electrolyte, and difficulty in controlling the product morphology. These issues not only impact the production efficiency and quality of electrolytic manganese but also result in severe environmental pollution. To address these issues, a MnSO4-(NH4)2SO4 electrolyte system was prepared based on the electrolytic manganese industry standard. The effects of polyacrylic acid, glycine, ethylenediaminetetraacetic acid (EDTA), and gluconic acid were explored as auxiliary additives under neutral electrolysis conditions to lower the SeO2 content, which is a highly toxic main additive. The effects of the different additives on the metal manganese morphology, crystal structure, and cathodic electrochemical polarization behavior were examined by field-emission scanning electron microscopy, X-ray diffraction, and constant current cathodic polarization curve tests. The findings reveal that the main orientation of the metal manganese crystal form deposited by the four auxiliary additives is the (330) crystal plane, and all of them can promote the formation of α-Mn, enhance the electrolysis efficiency, and lower the energy consumption. In particular, the optimized amount of polyacrylic acid of 0.08 g·L−1 contributes to an energy consumption of 5735.34 kW·h·t−1. Correspondingly, the addition of 10 g·L−1 glycine is the most favorable amount, leading to an energy consumption of 5518.56 kW·h·t−1. For EDTA, the lowest energy consumption of 5168.26 kW·h·t−1 is measured at an added amount of 0.5 g·L−1. Note that among the four investigated candidates, gluconic acid is the most favorable auxiliary additive, contributing to the increased cathode current density and reduced cathodic polarization as well as denser metal manganese products. Moreover, gluconic acid addition can lower the concentration of toxic SeO2 from 0.03–0.06 to 0.015 g·L−1, significantly increase the cathode current density, reduce the cathodic polarization, and result in a more dense and smooth product morphology, with the current efficiency being increased from approximately 70% to 89.73% and energy consumption being reduced from 6500 to 4990.58 kW·h·t−1 at the same time. Gluconic acid, as the auxiliary additive, not only contributes to the best electrolysis indexes for electrolytic manganese but also facilitates the formation of metal manganese with the most desirable crystal structure. This work offers novel insights into the environmentally friendly production and cheap electrodeposition of metal manganese for the electrolytic manganese industry.

The aim of copper hydrometallurgy is to produce high-quality cathode copper with the lowest energy consumption and the highest current efficiency. How to achieve this objective has become the focus of research. The anode material significantly influences the anode overpotential, current efficiency and cathode copper quality. Therefore, developing energy-saving anodes holds great practical significance for the copper electrowinning industry. The introduction of alloying element such as Ag, Ca, Co and Re into the lead alloy anode can enhance the mechanical strength of lead alloy, inhibit lead dissolution, and improve its electrocatalytic activity and corrosion resistance; the fabrication of composite anodes with active layers such as β-PbO2, IrO2-Ta2O5, TiB2/β-PbO2 and Co3O4 on conductive substrates, which possess excellent conductivity and catalytic activity, can enhance the anode’s corrosion resistance and reduce the oxygen evolution overpotential; it is found that graphite, lead with a three-dimensional structure and the PANI/Co3O4 composite can enhance both the active specific surface area and current efficiency of anode. By adjusting the copper acid ratio in the electrolyte from 0.25 to 0.30, and adding guar gum, thiourea and Co2+, the performance of the anode can be enhanced and the quality of the cathode copper can be improved. Furthermore, optimizing process conditions such as the temperature of the electrolyte and electrode spacing can also impact the anode’s lifespan and catalytic activity. In this paper, energy-saving measures for hydrometallurgical copper refining were mainly introduced from three aspects: the development of oxygen-evolving anodes, adjustments to the solution system, and optimization of process parameters. Finally, the future development direction of energy-saving in copper electrowinning was discussed.

A cyanide-free copper(I)-based bath for direct electroplating on steel substrate was developed. The effect of thiourea as complexing agent on the electrodeposition of copper(I) ion was studied electrochemically. The adhesion, surface morphology, elemental composition, and phase structure of the electroplated copper coating were characterized by cross-cut testing, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD), respectively. The results showed that thiourea could form a stable complex with Cu(I) ion, resulting in a much more negative deposition potential of Cu(I) ion, and avoiding the displacement reaction between copper and iron when conducting the electrodeposition of copper directly on steel substrate. The given bath had a wide range of working current density at a temperature not lower than 60 °C. Both cathodic and anodic current efficiencies of the bath are higher than 95%. A smooth, compact, fine-grained, highly pure, and well-adhered copper coating could be electrodeposited directly on steel in the given bath. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China Normal University (Natural Science Edition) / Huanan Shifan Daxue Xuebao (Ziran Kexue Ban) is the property of Journal of South China Normal University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ObjectiveTo prevent the marine biofouling adhesion and corrosion of ship hulls and pipes, a system is designed which produces chlorine through seawater electrolysis using an ion-exchange membrane electrolytic bath. Thereby, the law and efficency of the electrolytic bath under different conditions is studied. MethodsFirst, the effects of brine temperature, brine concentration, current density and time of brine resided in the bath on the efficiency of the electrolysis process are investigated. Minitab software is then used to optimize the parameters of the electrolysis process using the specific energy consumption rate as the evaluation index. Finally, the seawater pretreatment process and electrolysis process are verified on site under real sea conditions. ResultsThe current density and residence time of the electrolysis parameters were reasonably controlled at 3 000 A/m2 and 46 s respectively，in this case, the current efficiency was higher than 80%, the cell voltage was lower than 6 V, and the surfaces of the anodes, cathodes and ion-exchange membranes after electrolysis were clean. ConclusionThe practical tests show that this system can produce chlorine for anti-fouling.

The effect of mass concentration of isophthalaldehyde on electrodeposition behavior of tin during electroplating in a methanesulfonic acid (MSA) bath and the properties of the tin coating obtained was studied by cyclic voltammetry, polarization curve measurement, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results showed that isophthalaldehyde could increase the cathode polarization for tin electroplating, facilitating the formation of a compact and bright coating. The current efficiency was up to 99.23%, the electrodeposition rate was 57.977 μm/h, and the tin coating obtained was uniform and compact with a strong texture of (220) crystal plane when electroplating with 0.10 g/L of isophthalaldehyde. [ABSTRACT FROM AUTHOR]

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The preparation of ferrate by electrolytic method is favored by researchers because of its advantages of no pollutcing the current efficiency and ferrate concentration in the process of preparing ferrate were discussed emphatically, analyzes and summarizes the methods to improve the current efficiency and ferrate concentration in the process of electrolysis, and provides a theoretical basis for the industrial application of ferrate. In the future, efforts should be made in electrode improvement, stabilizer and ultrasonic mixing, and optimize the preparation process of ferrate to continuously improve the preparation concentration of ferrate. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

At high current density, the effects of fence type anode plate and conventional lead alloy anode plate on the current efficiency, coating morphology and cross-section morphology of electrowinning copper were studied. The structure and surface morphology of cathode copper were characterized by scanning electron microscopy, metallographic microscope and electrochemical workstation. The results show that the performance of the two anode plates are similar at low current density, and at 400 A/m² current density, compared with the conventional lead-based alloy anode plate, the copper output of fence-type anode plate is increased by about 15%, which exhibits superior current distribution uniformity and conductivity during electrolysis. The cell voltage of fence-type anode is 30~50 mV lower than that of the conventional lead alloy anode at the same current density, and the advantages of fence-type anode are more obvious with increasing of current density. In order to improve the crystal structure and the surface quality of copper at high current density, it is important to increase the concentration of copper ions in the electrolyte, the electrolyte circulation volume and the additives amount in the production process, which can improve grade, surface quality and crystalline structure of the copper cathode. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)