JSC Uralelectromed, Verkhnyaya Pyshma, Russia:

N. E. Agarova, Leading Engineer-Technologist of the Laboratory for Electroc hemical Production of the Research Center, e-mail: N.Agarova@elem.ru
L. M. Yakovleva, Head of the Laboratory for Electrochemical Production of the Research Center, e-mail: L.Yakovleva@elem.ru

JSC Uralelectromed, Verkhnyaya Pyshma, Russia¹ ; UMMC Technical University, Verkhnyaya Pyshma, Russia²:
K. L. Timofeev, Head of the Technical Department of Engineering and Production Management¹, Associate Professor of the Сhair for Metallurgy², Candidate of Теchnical Sciences

In recent years, ultrafine copper powder has become one of the most promising industrial materials due to its unique physical and chemical properties. For example, the high electrical conductivity of the powder allows to use it as a conductive paste or screen for protection against electromagnetic waves. JSC Uralelectromed is a unique enterprise in Russia with multi-tonnage production of copper electrolytic powder. The particle size of the powders varies depending on the brand in a wide range — from 5 to 250 microns. It is necessary to obtain ultrafine copper powder with an average particle size of 3 to 6 μm. The literature review showed the possibility to obtain ultrapowders by chemical methods and electrolysis from various media. However, the above examples of obtaining ultrafine copper powder differ significantly from the JSC Uralelectromed technology. Therefore, laboratory experiments were performed to optimize the existing electrolysis mode and determine the effect of the electrolyte components concentration and cathode current density on the process of obtaining a powder with a high content of fractions up to 5 μm. Regression equations were compiled, which showed the predominant effect of chloride ions and sulfuric acid, whose growth results in increase in the content of the required fraction. Industrial tests, in addition to the modified electrolysis step, included experiments on the separation of the powder on an air-centrifugal classifier. The range of the optimal specific surface and the average particle size of the initial (before classification) powder was determined. The modes of operation of the air classifier to obtain the required fractional composition of the powder were also determined. The specific surface area of the obtained ultrapowders ranged from 4400 to 5600 cm²/g.

1. Ryzhonkov D. I., Lyovina V. V., Dzidziguri E. L. Nanomaterials: tutorial. 2^nd edition. Moscow : BINOM. Laboratoriya znaniy, 2010. 365 p.
2. Pat. 0286164 EP. Process for preparing powders of non-ferrous metals or metal alloys. Bernd Dr. Langner, Artur May, René-Holger Wilde. Applied: 26.03.1998. Published: 12.10.1988.
3. Pat. 101279377 CN. Method for preparing spherical superfine copper powder. Li Y., Jun W., Liu H., Zhang Y. et al. Applied: 15.05.2008. Published: 08.10.2008.
4. Peng Y., Lee C., Popuri S., Kumar K. Preparation of high-purity ultrafine copper powder in mass-production by chemical reduction method: Taguchi robust design optimization. Materials Science, Powder Metallurgy and Metal Ceramics. 2016. Vol. 55. pp. 386–396.
5. Pat. 103388160 СN. A circuit board with a solution of copper waste – electrodeposited copper powder prepared with the use of the method. Li J., Zhang X., Wang K., Lei Y. et al. Applied: 19.10.2013; Published: 13.11.2013.
6. Baeshov K. A., Baeshov A., Konurbaev A. E., Baeshova A. K., et. al. Method of obtaining ultrafine copper powder. Patent KZ No. U 1600. Applied: 29.01.2016. Published: 15.08.2016. Bulletin No. 9.
7. Vnukov А. А., Roslik I. G., Chigirinets Е. E. Optimization of electrolysis process factors in order to obtain ultrafine copper electrolytic powder. Inzheneriya poverkhnosti. Novye poroshkovye kompozitsionnye materialy. Svarka. Part 1. 2011. pp. 87–92.
8. Pat. 2000080408 JP. Production of fine copper powder. Kenzo Hanawa, Kazuaki Takahashi. Applied: 31.08.1998. Published: 21.03.2000.
9. Pat. 201726980 TW. Method for producing copper powder, and method for producing conductive paste using the same. Yu Yamashita, Hiroshi Okada. Applied: 22.09.2016. Published: 01.08.2017.
10. Demeev B., Dauletbay A., Nauryzbayev M. The effect of organic surface-active additives upon the kinetics of electrodeposition of ultrafine copper powder. Chemical Engineering Transactions. 2016. Vol. 47. pp. 211–216.
11. Yue S. X., Su Y. C., Luo Z. B. et al. Influence of surfactant interaction on ultrafine copper powder electrodeposition. Materialwissenschaft und Werkstofftechnik. 2019. Vol. 50. pp. 856–863.
12. Ostanina Т. N., Murashova I. B., Kuzmina Е. Е. Dynamics of growth of lead dendritic precipitates on a cylindrical electrode. Elektrokhimiya. 1996. Vol. 32, No. 11. pp. 1329–1333.
13. Murashova I. B., Taushkanov P. V., Burkhanova N. G. Change in the structural characteristics of loose copper precipitate during galvanostatic electrolysis. Elektrokhimiya. 1999. Vol. 35, No. 7. pp. 835–840.
14. Murashova I. B., Burkhanova N. G. Calculation of structural changes of dendritic precipitates during galvanostatic electrolysis. Elektrokhimiya. 2001. Vol. 37, No. 7. pp. 871–877.
15. Nichiporenko О. S., Pomosov А. V., Naboychenko S. S. Powders of copper and its alloys. Moscow : Metallurgiya, 1986. 204 p.
16. Sundus Abbas Jasim, Sajad Abd Al-kadhum Mohsin, Abd Al-kadhum Mohsin. Production of copper powder from ores by elecrodeposition process. Journal of University of Babylon for Engineering Sciences. 2019. Vol. 27, No. 2.
17. Artamonov V. P., Pomosov А. V. On effect of chlorine ions on cathodic polarization in copper sulfate solutions. Elektrokhimiya. 1976. No. 8. pp. 1331–1334.
18. Sokolovskaya Е. Е., Murashova I. B., Lebed` А. B., Osipova М. L. The pursuit of maximal possible period for copper dendritic electrocrystallization between its take off the cathode. Tsvetnye Metally. 2010. No. 1. pp. 36–39.