Optimizing Copper Production from Scrap: The Impact of Heat Treatments on Purity and Yield
DOI:
https://doi.org/10.56801/MME1097Keywords:
Thermal refining; Purity; Isothermal holds; Holding times; Volatility of impurities; mass losses.Abstract
R Recent research has focused on improving the copper purification process to meet the strict purity requirements, particularly in sectors such as aerospace. This study investigates the use of thermal refinings on samples of copper scrap before melting at specific temperatures between 373 K and 1223 K. These samples were melted and then cast at 1393 K, which has been confirmed in previous studies as the optimum temperature to achieve higher purity from copper scrap. The first thermal refinements consist of continuous heating with isothermal holds at the specified temperatures, with each refining having a holding time of 5, 10, 15, or 20 minutes set at the beginning. By exploiting the volatility of certain impurities (Zn, As and P) and the oxidation of others, this process has significantly improved the purity of the casting copper from 99.9230 .wt% to 99.9714 .wt%. Despite these improvements, significant mass losses were observed at the end of thermal refining for equivalent holding times greater than 10 minutes. These mass losses are mainly due to degradation of thin copper wire. To remedy this, thermal refinings with different holding times were tested. One of these latest refinings not only improved the purity to 99.9716.wt% and reached a thermal conductivity of approximately 360 W/m·K , but also reduced the total refining holding time to 94 min. These results help optimize copper purification processes by reducing costs and mass losses while improving overall efficiency.
References
Exploring future copper demand, recycling and associated greenhouse gas emissions in the EU-28 https://doi.org/10.1016/j.gloenvcha.2020.102093
Jain, P. K., Recycling of metal scraps—a positive concept leading to augmentation of reserve base. Mineral Economics, 25(1), 45–51 (2011) . DOI:10.1007/s13563-011-0007-4
https://www.researchgate.net/publication/270048511
Copper recycling and scrap availability https://doi.org/10.1016/j.resourpol.2007.08.002
The limitations of end-of-life copper recycling and its implications for the circular economy of metals https://doi.org/10.1016/j.resconrec.2023.107318
Extractive metallurgy of copper chapter collection processing of recycled copper page 376-377
William D. Riley, Harry V. Makar , Impurity effects in secondary copper alloys & Recycling. 9(4), 315–323 (1986).DOI: https://doi.org/10.1016/0361-3658(86)90066-4
Sa Xiao, Wei Xiong, Lijun Wang, Qiaolin Ren. Atlantis Press .(2016) DOI:10.2991/icseee-15.2016.82
Antonia Loibl, Luis A. Tercero Espinoza, Current challenges in copper recycling: aligning insights from material flow analysis with technological research developments and industry issues in Europe and North America. Resources, Conservation and Recycling. 169 (2021). DOI: https://doi.org/10.1016/j.resconrec.2021.105462
Jirang Cui, Eric Forssberg, Mechanical recycling of waste electric and electronic equipment: a review. Journal of Hazardous Materials. 99(3), 243–263 (2003). DOI: https://doi.org/10.1016/S0304-3894(03)00061-X
Current challenges in copper recycling: aligning insights from material flow analysis with technological research developments and industry issues in Europe and North America https://doi.org/10.1016/j.resconrec.2021.105462
Behaviour of Impurities during Electron Beam Melting of Copper Technogenic Material https://doi.org/10.3390/ma15030936
https://www.researchgate.net/publication/310503800
Study of ultrahigh-purity copper billets refined by vacuum melting and directional solidification DOI: 10.1007/s12598-011-0388-0
Preparation of high-purity copper through vacuum distillation https://doi.org/10.1016/j.vacuum.2023.112566
Production of ultrahigh purity copper using waste copper nitrate solution DOI:10.1016/S0304-3894(02)00312-6
Complex electronic waste treatment – An effective process to selectively recover copper with solutions containing different ammonium salts https://doi.org/10.1016/j.wasman.2016.03.015
Efficient separation of impurities in scrap copper by sulfurization-vacuum distillation DOI: 10.1007/s12598-011-0388-0
Production of ultrahigh purity copper using waste copper nitrate solution https://doi.org/10.1016/S0304-3894(02)00312-6
Md. Mominul Haque, Hyungsub Kim, Man-Sik Kong, Hyun-Sun Hong, Kyung-Sub Kim, Caroline Sunyong Lee, Recycling copper from waste copper wire using an applied voltage. International Journal of Precision Engineering and Manufacturing. 13(7), 1251–1254 (2012). DOI:10.1007/s12541-012-0167-3
Smalcerz, L. Blacha, Removal of Lead From Blister Copper by Melting in the Induction Vacuum Furnace. Archives of foundry engineering, 20 (2), 84-88. (2020). DOI: http//10.24425/afe.2020.131307
Smalcerz, L. Blacha, Vacuum refinning cooper blister to remove antimony. Metalurgija .59 (3), 358-360. (2020). DOI: https://hrcak.srce.hr/file/344190
N. K. Dosmukhamedov, E. E. Zholdasbay, G. B. Nurlan, Ultra-pure Cu obtaining using zone melting: influence of liquid zone width on impurities’ behaviour. Heavy non-ferrous metals. (2), 15–20 (2017). DOI: 10.17580/nfm.2017.02.03
Dosmukhamedov N. K , Zholdasbay E. E, Nurlan G. B, Kurmanseitov M. B, Employment of zone melting to obtain ultrapure Cu: behavioural patterns of impurity metals. Tsvetnye Metally. 7, 34–41(2017). DOI:10.17580/tsm.2017.07.06
Jinyue Liu, Yingbao Yang , Bo Li , Yonggang Wei, Phase Transformation of Impurity Elements and High-efficiency Impurity Removal in Complex Copper Concentrate Smelting Process. Springer link. 40, 1639-1653,(2023).DOT:10.1007/s42461-023-00827-w
Choukri.O, Mohsine.E, Souadi.T, Optimizing melting temperatures for high-purity copper recovery from scrap sources
http://www.brammerstandard.com/certificates/bs110C.pdf
Villarroel. D, Process for refining copper in solid state. Minerals Engineering, 12(4), 405–414. (1999). DOI: 10.1016/s0892-6875(99)00020-5
Perry’s Chemical Engineers Handbook 9th Edition page 2-59
Copper Production. (2014). Treatise on Process Metallurgy, 534–624. doi:10.1016/b978-0-08-096988-6.00027-4
https://faculty.utrgv.edu/samantha.ramirez/MECE3160/3160TCS.pdf
J. Tuttle, E. Canavan, M. DiPirro, thermal and electrical conductivity measurements of cda 510 phosphor bronze (2010). DOI:10.1063/1.3402333
Zhaomeng Wang , Qianchu Li , Jie Ren , Jie Chen , Yingbo Zhang , Hui Chen , Hongmei Liu, Prediction of electrical/thermal conductivity in as-cast Mg binary alloys. Journal of Materials Research and Technology 27, 5924–5934 (2023).
M. C. I. Siu, W. L. Carroll, T. W. Watson, Thermal Conductivity and Electrical Resistivity of Six Copper-Base Alloys (1976).
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