Economic considerations for stripping precious metals coatings (chemically and electrochemically) | ||||
| International Design Journal | ||||
| Article 2, Volume 10, Issue 1, January 2020, Page 33-45 PDF (1.08 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/idj.2020.81288 | ||||
 View on SCiNiTO | ||||
| Author | ||||
| Mohamed Al Awamy Mohammed | ||||
| Assistant Professor-Metal Products and Jewelry department –Faculty of Applied Arts, Benha University | ||||
| Abstract | ||||
| Electroplating is a surface treatment technique to enrich the aesthetic appearance of the product and protect it from corrosion that leads to distortion of metal surfaces and to achieve these requirements in the product uses precious metals coatings such as silver, gold, platinum and others to cover the metal surface and maintain it from various environmental factors by taking advantage of the unique characteristics of these metals. Hence, the Electroplating process has some problems and defects that occur to the coating such as surface roughness and poor adhesion and other defects with which it is difficult to perform the surface of the plated product for its functions, whether it is useful or aesthetic, Forcing Electroplater to strip the coating and replace it with other properties better and free from defects. This may have an economic impact on the production processes because of the loss of time, energy and effort as a result of the repetition of some operations. Stripping precious metal coatings from the surface of any product is a difficult and challenging process that most Electroplater do not like. However, some engineering and metallic products (such as jewelery) may need to be removed for some unsuccessful coatings, to correct errors or to improve the appearance of the product. Statement of problem. Therefore, the problem of research is determined by the need to avoid the economic effects resulting from the waste of precious metals, especially gold and silver when replating metal products, whether for defects appear after the completion of the coating process or improve the appearance of the product. Objectives: Identify the most important chemical and electrochemical methods to remove the layers of metallic coatings from the surfaces of painted products, whether new or unpainted to improve the appearance and acknowledge the methods of extracting metals from removal solutions to preserve them, especially precious ones such as gold and silver. In addition to the determination of economic values to remove paint layers. Research Methodology: The research uses the descriptive analytical and experimental method. Results. 1.The Electroplating process has some problems and defects that occur to the coating layer such as surface roughness, poor adhesion and other defects with which it is difficult to perform the surface product for its functions, whether it is useful or aesthetic, which causes stripping of the coating and replace it with other properties better and free from defects. 2- The actual utilization of metals used in electroplating processes shall not exceed 30% to 40% of the total metals used in this process. 3 - Stripping of metal coating, especially precious from the surface of any product is a difficult process and a challenge not preferred by most workers in the field of plating. 4 - There are several methods of mechanical, chemical and electrochemical to strip the metal coating where it depends on the friction or immersion in solutions (chemical) or anodic units (electrically) deposition of metal ions on cathodes. 5- After successful strip coatings must take advantage of the metals that have dissolved in the stripping solutions because its large economic value, especially when stripping precious metals such as gold and silver, and the most common methods in the application, which relied on research in practical experiments, the method of chemical deposition and the method of Electrowinning 6 - The processes of stripping coating of metal plated several economic values | ||||
| Keywords | ||||
| الاعتبارات الاقتصادية; Economic considerations; ازالة طبقات الطلاء; coatings stripping; المعادن الثمينة; precious metals | ||||
| References | ||||
|
1- Janikowski, S.K., et al.- 1989.- Noncyanide Stripper Placement Program.- Air Force Engineering & Services Center. ESL- TR- 89- 07
2- T. Jones, M.1.M.F- 2004- Stripping of Precious Metal Coatings- Metal Finishing, Volume 102, Issue 2, , Pages 14- 21
3- G. N. K. Ramesh Bapu*, C. Eagammai and S. Jayakrishnan- 2008 - Electrolytic recovery of silver from low concentrated silver cyanide spent plating solutions- Institute of Metal Finishing- Maney on behalf of the Institute- p.p.67- 72
4- Sekar, T. C. Selvi, C. Eagammai and S. Jayakrishnan- 2007- Chemical stripping of gold deposits from different substrates- Transactions of the Institute of Metal Finishing - VOL 85 NO 3 R
5- D.R.Gabe Iptme- 2006- Metal Strippers: Their Science And Technology., Loughborough University, LE11 3TU, UK. Trans Inst Met Fin Tutorial Series. www.PF online.com- Enthone Inc. Posted on: 9/29/2011
6- Charles Rosenstein- 2011- Stripping Metallic - 12th Issue by Metal Finishing Magazine - New York- USA.
7- N.V parthosoradhy –1989- Practical Electroplating Handbook – New Jersey- U.S.A – Prentice Hall Inc- pp.307- 309
8- K.K. Wong, C.K. Lee , K.S. Low, M.J. Haron- 2003- Removal of Cu and Pb from electroplating wastewater using tartaric acid modified rice husk- Selangor, Malaysia- Chemistry Department, Faculty of Science and Environmental Studies, Universiti Putra Malaysia,
9- O. Gyliene, J. Aikaite, O. Nivinskiene, 2004- Recycling of Ni(II)–citrate complexes using precipitation in alkaline solutions, J. Hazard. Mater- pp.105 , 109–111. https://www.finishing.com/195/29.shtml- 25/7/2019
10- P. Gomathi Priyaa, C. Ahmed Bashab,∗, V. Ramamurthia, S. Nathira Begumb- 2008- Recovery and reuse of Ni(II) from rinsewater of electroplating industries- Department of Chemical Engineering, A.C. College of Technology, Anna University, Chennai 600025, India
11- Wong Wai Leong Eugene and Arun S. Mujumdar- Mar 2009- Gold Extraction and Recovery Processes- Minerals, Metals and Materials Technology Centre (M3TC), Faculty of Engineering, National University of Singapore-
12- D.R.Gabe Iptme- 2006- Metal Strippers: Their Science And Technology., Loughborough University, LE11 3TU, UK. Trans Inst Met Fin Tutorial Series
13- G. N. K. Ramesh Bapu, C. Eagammai and S. Jayakrishnan- 2008- Electrolytic recovery of silver from low concentrated silver cyanide spent plating solutionsInstitute of Metal Finishing- Maney on behalf of the Institute- p.p.67- 72
14- Pilar González1, F. Javier Recio2- 2011- Silver Recovery from Acidic Solutions by Formation of Nanoparticles and Submicroparticles of Ag on Microfiltration Membranes- - España- Universidad Autónoma de Madrid, Madrid- InTech Europe- pp.439- 440
15- Lei Zhu1,a,Jingsong Wang1,b, Zhengwei Xiong1,c, - 2015.- Recovery of Nickel by Electrolytic Method from Electroplating Wastewater- University of South China, Hengyang- China- Atlantis Press-
16- Wen- juan Zhang,Ling Liu, Cheng- mei Li.Industrial Safety and Environmental Protection,Vol.32(2006),P.35(in Chinese) | ||||
|
Statistics Article View: 300 PDF Download: 1,444 |
||||
