Study on Electrochemical Performance of Dimensionally Stable Anodes during Zinc Electrowinning
In zinc electrowinning, small amounts of manganese ions additives are needed in the electrolyte to reduce the corrosion of anodes and minimize the contamination of cathodic zinc by dissolved lead. However, excess manganese oxide could cover the dimensionally stable anodes (DSA) surface and decrease...
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Polish Academy of Sciences
2023-12-01
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| Series: | Archives of Metallurgy and Materials |
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| Online Access: | https://journals.pan.pl/Content/129651/PDF/AMM-2023-4-27-Zhang.pdf |
| _version_ | 1797379915579916288 |
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| author | Wei Zhang Georges Houlachi Sanae Haskouri Edward Ghali |
| author_facet | Wei Zhang Georges Houlachi Sanae Haskouri Edward Ghali |
| author_sort | Wei Zhang |
| collection | DOAJ |
| description | In zinc electrowinning, small amounts of manganese ions additives are needed in the electrolyte to reduce the corrosion of anodes and minimize the contamination of cathodic zinc by dissolved lead. However, excess manganese oxide could cover the dimensionally stable anodes (DSA) surface and decrease their service life. Additives of phosphoric acid are put in the electrolyte to complex the manganic Mn3+ ion and hence reduce its disproportionation to MnO2. In the investigation, phosphoric acid was added to sulfuric acid or zinc electrolytes, and conventional and recent electrochemical measurements were carried out to examine electrochemical behaviour of DSA (Ti/IrO2-Ta2O5) anode during zinc electrolysis at 48 mA/cm2 and 39°C. It was observed that the anodic potentials of DSA anodes were lower by 27 mV after 5 h polarization in the zinc electrolyte containing 35 g/L phosphoric acid at 39°C. Electrochemical impedance measurements show that the addition of 35 ml/L H3PO4 to the zinc electrolyte can increase impedance resistances of the DSA mesh anodes. Cyclic voltammogram studies (CV) at a scan rate of 5 mV/s without agitation show that the oxidation peak in the solution with 35 ml/L phosphoric acid addition is highest, followed by that with 17 ml/L phosphoric acid addition and that without addition of phosphoric acid. |
| first_indexed | 2024-03-08T20:29:58Z |
| format | Article |
| id | doaj.art-6ac802042924464682e9dc64b7874ff2 |
| institution | Directory Open Access Journal |
| issn | 2300-1909 |
| language | English |
| last_indexed | 2024-03-08T20:29:58Z |
| publishDate | 2023-12-01 |
| publisher | Polish Academy of Sciences |
| record_format | Article |
| series | Archives of Metallurgy and Materials |
| spelling | doaj.art-6ac802042924464682e9dc64b7874ff22023-12-22T14:27:45ZengPolish Academy of SciencesArchives of Metallurgy and Materials2300-19092023-12-01vol. 68No 414571466https://doi.org/10.24425/amm.2023.146212Study on Electrochemical Performance of Dimensionally Stable Anodes during Zinc ElectrowinningWei Zhang0https://orcid.org/0000-0003-2502-3498Georges Houlachi1https://orcid.org/0000-0003-2708-0592Sanae Haskouri2https://orcid.org/0000-0003-0355-5709Edward Ghali3https://orcid.org/0000-0001-8164-6505Hunan University of Technology, School of Metallurgical, ZhuZhou, China, 412002Hydro-Québec research institute, Shawinigan, QC, Canada, G9N 7N5Laval University, Department of Mining, Metallurgical and Materials Engineering, Quebec, QC, Canada, G1K 7P4Laval University, Department of Mining, Metallurgical and Materials Engineering, Quebec, QC, Canada, G1K 7P4In zinc electrowinning, small amounts of manganese ions additives are needed in the electrolyte to reduce the corrosion of anodes and minimize the contamination of cathodic zinc by dissolved lead. However, excess manganese oxide could cover the dimensionally stable anodes (DSA) surface and decrease their service life. Additives of phosphoric acid are put in the electrolyte to complex the manganic Mn3+ ion and hence reduce its disproportionation to MnO2. In the investigation, phosphoric acid was added to sulfuric acid or zinc electrolytes, and conventional and recent electrochemical measurements were carried out to examine electrochemical behaviour of DSA (Ti/IrO2-Ta2O5) anode during zinc electrolysis at 48 mA/cm2 and 39°C. It was observed that the anodic potentials of DSA anodes were lower by 27 mV after 5 h polarization in the zinc electrolyte containing 35 g/L phosphoric acid at 39°C. Electrochemical impedance measurements show that the addition of 35 ml/L H3PO4 to the zinc electrolyte can increase impedance resistances of the DSA mesh anodes. Cyclic voltammogram studies (CV) at a scan rate of 5 mV/s without agitation show that the oxidation peak in the solution with 35 ml/L phosphoric acid addition is highest, followed by that with 17 ml/L phosphoric acid addition and that without addition of phosphoric acid.https://journals.pan.pl/Content/129651/PDF/AMM-2023-4-27-Zhang.pdfzinc electrowinningdimensionally stable anodesmanganese ionsphosphoric acidelectrochemical performance |
| spellingShingle | Wei Zhang Georges Houlachi Sanae Haskouri Edward Ghali Study on Electrochemical Performance of Dimensionally Stable Anodes during Zinc Electrowinning Archives of Metallurgy and Materials zinc electrowinning dimensionally stable anodes manganese ions phosphoric acid electrochemical performance |
| title | Study on Electrochemical Performance of Dimensionally Stable Anodes during Zinc Electrowinning |
| title_full | Study on Electrochemical Performance of Dimensionally Stable Anodes during Zinc Electrowinning |
| title_fullStr | Study on Electrochemical Performance of Dimensionally Stable Anodes during Zinc Electrowinning |
| title_full_unstemmed | Study on Electrochemical Performance of Dimensionally Stable Anodes during Zinc Electrowinning |
| title_short | Study on Electrochemical Performance of Dimensionally Stable Anodes during Zinc Electrowinning |
| title_sort | study on electrochemical performance of dimensionally stable anodes during zinc electrowinning |
| topic | zinc electrowinning dimensionally stable anodes manganese ions phosphoric acid electrochemical performance |
| url | https://journals.pan.pl/Content/129651/PDF/AMM-2023-4-27-Zhang.pdf |
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