The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Göran Lindbergh - One of the best experts on this subject based on the ideXlab platform.
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Methanol and formic acid oxidation in zinc Electrowinning under process conditions
Journal of Applied Electrochemistry, 2008Co-Authors: M. Wesselmark, Carina Lagergren, Göran LindberghAbstract:The possibility of using methanol or formic acid oxidation as the anode process in zinc Electrowinning was examined. The activity for methanol and formic acid oxidation on Pt coated high surface area electrodes was investigated over 36 h, at a current density used in industry. The activity could be maintained at a constant potential level in a synthetic Electrowinning electrolyte if the current was reversed for short periods. During the tests, the anode potential was, more than 1.2 V below the potential for the oxygen evolving lead anodes used in modern zinc Electrowinning. The lowered anode potential would lead to a significant energy reduction. However, tests in industrial electrolyte resulted in a very low activity for both methanol and formic acid oxidation. The low activity was shown to be caused mainly by chloride impurities. A reduction of the chloride content below 10^−5 M is needed in order to obtain sufficient activity for methanol oxidation on Pt for use in zinc Electrowinning. Pt and PtRu electrodes were compared regarding their activity for methanol oxidation and the latter was shown to be more affected by chloride impurities. However, at a potential of 0.7 V vs NHE, with a chloride content of 10^−4 M, formic acid oxidation on PtRu gives the highest current density.
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Methanol Oxidation as Anode Reaction in Zinc Electrowinning
Journal of The Electrochemical Society, 2005Co-Authors: M. Wesselmark, Carina Lagergren, Göran LindberghAbstract:The lead anodes used in zinc Electrowinning today are not dimensionally stable and have a high overvoltage for oxygen evolution. By replacing the oxygen evolution in sulphate based electrolytes with methanol oxidation the anode potential could be lowered significantly. This would reduce the energy consumption and also enable the use of new and more stable types of electrodes. In this study, different types of electrodes were compared regarding their activity and stability for methanol oxidation in a zinc Electrowinning environment. The activities of the electrodes studied were sufficient for Electrowinning processes. The highest activity was obtained with porous PtRu, but platinised titanium was the most stable electrode. All electrodes were deactivated with time and the deactivation mechanism seemed to differ between Pt and PtRu. The best method for reactivation was to periodically reverse the current. The platinised titanium electrode was considered to be most suitable for use in Electrowinning processes.
L. Hermida - One of the best experts on this subject based on the ideXlab platform.
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Application of Taguchi optimization for nickel Electrowinning using batch recycle methods
2018Co-Authors: Sudibyo Sudibyo, A. Junaedi, Muhammad Amin, Anton Sapto Handoko, Slamet Sumardi, Fajar Nurjaman, Yayat Iman Supriyatna, L. HermidaAbstract:Low-grade laterite which has nickel content 0.5% has been processed using solvent extraction and followed by Electrowinning process. Cyanex which diluted in toluene was used as an organic solvent to separated cobalt from nickel solvent. In this work, nickel solvent which frees from cobalt was processed using Electrowinning. Electrowinning was conducted using batch recycle methods to ensure the Electrowinning performed well. Meanwhile, cylindrical cathode electrode was used to increase the performance of Electrowinning, easy to operate and easy to harvest. The parameters which have a significant effect in batch recycle methods such as flow rate, voltage and process duration. Taguchi analysis showed the optimum condition and the parameter which has the highest effect towards the mass of nickel electrodeposits.Low-grade laterite which has nickel content 0.5% has been processed using solvent extraction and followed by Electrowinning process. Cyanex which diluted in toluene was used as an organic solvent to separated cobalt from nickel solvent. In this work, nickel solvent which frees from cobalt was processed using Electrowinning. Electrowinning was conducted using batch recycle methods to ensure the Electrowinning performed well. Meanwhile, cylindrical cathode electrode was used to increase the performance of Electrowinning, easy to operate and easy to harvest. The parameters which have a significant effect in batch recycle methods such as flow rate, voltage and process duration. Taguchi analysis showed the optimum condition and the parameter which has the highest effect towards the mass of nickel electrodeposits.
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Application of Taguchi optimization for nickel Electrowinning using batch recycle methods
2018Co-Authors: Sudibyo Sudibyo, A. Junaedi, Muhammad Amin, Anton Sapto Handoko, Slamet Sumardi, Fajar Nurjaman, Yayat Iman Supriyatna, Bramantyo Bayu Aji, L. HermidaAbstract:Low-grade laterite which has nickel content 0.5% has been processed using solvent extraction and followed by Electrowinning process. Cyanex which diluted in toluene was used as an organic solvent to separated cobalt from nickel solvent. In this work, nickel solvent which frees from cobalt was processed using Electrowinning. Electrowinning was conducted using batch recycle methods to ensure the Electrowinning performed well. Meanwhile, cylindrical cathode electrode was used to increase the performance of Electrowinning, easy to operate and easy to harvest. The parameters which have a significant effect in batch recycle methods such as flow rate, voltage and process duration. Taguchi analysis showed the optimum condition and the parameter which has the highest effect towards the mass of nickel electrodeposits.
R F Sandenbergh - One of the best experts on this subject based on the ideXlab platform.
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effect of aluminium on polarisation parameters and deposit characteristics in typical nickel sulfate electrolyte for Electrowinning applications
Hydrometallurgy, 2020Co-Authors: Liezl Schoeman, Emmanuel N Nsiengani, Kathryn C Sole, R F SandenberghAbstract:Abstract Impurities present in the sulfate electrolyte during nickel electrodeposition influence the Electrowinning process and morphology of deposited nickel metal in various ways. The presence of aluminium can be either detrimental or beneficial, depending on its concentration. Effects of the presence of aluminium in the electrolyte during nickel Electrowinning were investigated by evaluation of the relationship between nucleation and plating overpotentials, nickel morphology, deposit contamination, internal stress development, and buffer characteristics of the electrolyte. Results showed that aluminium present at concentrations of lower than 1250 mg/L was unfavourable for the Electrowinning process and highly strained nickel deposits of poor morphology were produced; at higher concentrations, the presence of aluminium was advantageous for the morphology and internal stress, and correlated with increased buffer characteristics of the electrolyte.
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A study of the influence of copper on the gold Electrowinning process
Journal of The South African Institute of Mining and Metallurgy, 2004Co-Authors: J. Steyn, R F SandenberghAbstract:Electrowinning is an attractive method to recover gold from the relatively concentrated aurodicyanide solutions produced by the elution of loaded carbon, provided that the plated gold can be easily removed using high pressure water sprays. In practice, difficulty with the removal of the gold is occasionally experienced and has been correlated with the presence of high concentrations of copper in the eluate. In this work, the influence of copper on the electroplating of gold was further investigated using a laboratory Electrowinning cell with a rotating disc cathode, polarization, and adhesion tests. It was found that the reduction of copper will compete with gold Electrowinning at high copper tenors and that the adhesion of the precipitated gold is also increased under these conditions. Keywords: reduction, adhesion, morphology, current efficiency, limiting current.
M. Wesselmark - One of the best experts on this subject based on the ideXlab platform.
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Methanol and formic acid oxidation in zinc Electrowinning under process conditions
Journal of Applied Electrochemistry, 2008Co-Authors: M. Wesselmark, Carina Lagergren, Göran LindberghAbstract:The possibility of using methanol or formic acid oxidation as the anode process in zinc Electrowinning was examined. The activity for methanol and formic acid oxidation on Pt coated high surface area electrodes was investigated over 36 h, at a current density used in industry. The activity could be maintained at a constant potential level in a synthetic Electrowinning electrolyte if the current was reversed for short periods. During the tests, the anode potential was, more than 1.2 V below the potential for the oxygen evolving lead anodes used in modern zinc Electrowinning. The lowered anode potential would lead to a significant energy reduction. However, tests in industrial electrolyte resulted in a very low activity for both methanol and formic acid oxidation. The low activity was shown to be caused mainly by chloride impurities. A reduction of the chloride content below 10^−5 M is needed in order to obtain sufficient activity for methanol oxidation on Pt for use in zinc Electrowinning. Pt and PtRu electrodes were compared regarding their activity for methanol oxidation and the latter was shown to be more affected by chloride impurities. However, at a potential of 0.7 V vs NHE, with a chloride content of 10^−4 M, formic acid oxidation on PtRu gives the highest current density.
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Methanol and formic acid oxidising anodes in zinc Electrowinning
2006Co-Authors: M. WesselmarkAbstract:The possibility of using methanol or formic acid oxidation as the anode process in zinc Electrowinning was examined. The activity for methanol and formic acid oxidation on Pt coated high surface area electrodes was investigated over 36 h, at a current density used in industry. The activity could be maintained at a constant potential level in a synthetic Electrowinning electrolyte if the current was reversed for short periods. During the tests, the anode potential was, more than 1.2 V below the potential for the oxygen evolving lead anodes used in modern zinc Electrowinning. The lowered anode potential would lead to a significant energy reduction. However, tests in industrial electrolyte resulted in a very low activity for both methanol and formic acid oxidation. The low activity was shown to be caused mainly by chloride impurities. A reduction of the chloride content below 10(-5) M is needed in order to obtain sufficient activity for methanol oxidation on Pt for use in zinc Electrowinning. Pt and PtRu electrodes were compared regarding their activity for methanol oxidation and the latter was shown to be more affected by chloride impurities. However, at a potential of 0.7 V vs NHE, with a chloride content of 10(-4) M, formic acid oxidation on PtRu gives the highest current density.
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Methanol Oxidation as Anode Reaction in Zinc Electrowinning
Journal of The Electrochemical Society, 2005Co-Authors: M. Wesselmark, Carina Lagergren, Göran LindberghAbstract:The lead anodes used in zinc Electrowinning today are not dimensionally stable and have a high overvoltage for oxygen evolution. By replacing the oxygen evolution in sulphate based electrolytes with methanol oxidation the anode potential could be lowered significantly. This would reduce the energy consumption and also enable the use of new and more stable types of electrodes. In this study, different types of electrodes were compared regarding their activity and stability for methanol oxidation in a zinc Electrowinning environment. The activities of the electrodes studied were sufficient for Electrowinning processes. The highest activity was obtained with porous PtRu, but platinised titanium was the most stable electrode. All electrodes were deactivated with time and the deactivation mechanism seemed to differ between Pt and PtRu. The best method for reactivation was to periodically reverse the current. The platinised titanium electrode was considered to be most suitable for use in Electrowinning processes.
Jae-woo Ahn - One of the best experts on this subject based on the ideXlab platform.
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recovery of copper tin and lead from the spent nitric etching solutions of printed circuit board and regeneration of the etching solution
Hydrometallurgy, 2003Co-Authors: Man-seung Lee, Jong-gwan Ahn, Jae-woo AhnAbstract:Abstract In order to recover valuable metals and regenerate the etching solution from the spent nitric etching solutions of printed circuit board (PCB), solvent extraction, stripping, Electrowinning, precipitation and cementation experiments have been performed. Nitric acid was selectively extracted by TBP from the spent etching solution and pure nitric acid solution was stripped by distilled water. After extracting nitric acid, pure copper metal was obtained by Electrowinning and tin ions were precipitated by adjusting the pH of solution with Pb(OH) 2 . Lead metal with purity of 99% was obtained by cementation with iron powder.