Recycle of Contaminated Zinc-Nickel Plating Bath by Selective Recovery of Iron

Document Type : Research Article

Authors

Mining Engineering Department, University of Dokuz Eylul, Buca, TÜRKIYE

Abstract

Electroplating is a preferred method of coating the surface of metallic materials such as steel for wear and appearance reasons. Recently, zinc, nickel, or zinc-nickel coatings have been widely used to prevent corrosion of vehicle parts such as brake pads and connecting equipment. However, in the plating bath used in the plating processes, iron contamination might occur due to the partial dissolution of the metal parts over time, causing dark-colored defects on the plating material during electroplating. In this study, the recycling of the plating bath electrolyte by precipitation of iron ions from the solution was investigated. The addition of 7 g/L zinc dust at 30° C minimized the iron concentration in a short time (20 minutes) without affecting the quality and content of the coating bath. The chemical and physical analyses of the precipitate and electrolytes were performed by AAS, XRD, and EDX. The galvanic quality of the decontaminated electrolyte was tested at a current density of 250 A /m2 and 298 K.

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[1] Schario M., “Better Alloy Control of Alkaline Zinc Nickel Baths”, Product Finishing Magazine, Columbia, (2017).
[2] Gatto G, Nahlawi Jr.T, Kramer R., Flesch J.,  What Engineers Should Know about Zinc-Nickel Coatings?, Machine Design, Sourceesb, 26-32 (2017).
[3] Muresan L.M., Eymard J., Blejan D., Indrea E., Zn-Ni Alloy Coatings from Alkaline Bath Containing Triethanolamine Influence of Additives, Studia Universitatis Babeş-Bolyai. Chemia, 55(1): 37-44 (2010).
[4] Chatterjee B., Electrodeposition of Zinc Alloys, Jahrbuch Oberflachen Technik, 62: 76-105 (2006).
[5] Altuncu E., “Which is the Best Plating Practice for Zn-Ni Deposition? Barrel or Rack Plating”, Turkchem News Portal, (2019).
[6] Qu Z., Su T., Zhu S., Chen Y., Yu Y., Xie X., Yang J., Huo M., Bian D., Stepwise Extraction of Fe, Al, Ca, and Zn: A Green Route to Recycle Raw Electroplating Sludge, Journal of Environmental Management, 300: 1-13 (2021).
[7] Lian J., Chen Q., Hu H., Wang W., Deep Purification of Zinc Ammoniacal Leaching Solution by Cementation with Zinc Dust, The Chinese Journal of Process Engineering, 10: 879-885, (2010).
[8] Van der Pas V., Dreisinger D.B., A Fundamental Study of Cobalt Cementation by Zinc Dust in the Presence of Copper and Antimony Additives, Hydrometallurgy, 43: 187−205 (1996).
[9] Yuea T., Niub Z., Hua Y., Hana H., Lyua D., Suna W., Cr(III) and Fe(II) Recovery from the Polymetallic Leach Solution of Electroplating Sludge by Cr(III)-Fe(III) Coprecipitation on Maghemite, Hydrometallurgy, 184: 132-139 (2019).
[11] Roine A., HSC Chemistry©5.0. Outokumpu Research, Finland, (2002).
[12] Brett C., Brett A.M., Electrochemistry Principles, Methods and Applications, Oxford Science Publications, NY. 326 (1993).