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ArticleName Co-deposition of copper in trans-dichlorodiaminepalladium salt
DOI 10.17580/tsm.2019.09.03
ArticleAuthor Ryumin A. I., Belousov O. V., Sorkinova G. A., Sirotina D. Yu.

Siberian Federal University, Krasnoyarsk, Russia:

A. I. Ryumin, Associate Professor at the Department of Non-Ferrous Metallurgy
O. V. Belousov, Associate Professor at the Department of Non-Ferrous Metallurgy, e-mail:
G. A. Sorkinova, Senior Lecturer at the Department of Non-Ferrous Metallurgy
D. Yu. Sirotina, Postgraduate Student


In palladium refining, the trans-dichlorodiaminepalladium salt serves as the basic compound for selective extraction of palladium from complex solutions. The final salt of trans-[Pd(NH3)2Cl2], which is then used to produce refined metallic palladium, is subjected to hydrochloric acid deposition from ammonia solution containing non-ferrous metal impurities. Copper is the dominant impurity in refined palladium. This research aimed to understand the process of co-deposition of copper with dichlorodiaminepalladium. Copper (I) and (II) chlorides were introduced in the ammonia solution of palladium salt [Pd(NH3)4]Cl2. Dichlorodiaminepalladium was then deposited from the solution, and the salt that formed was analysed for copper content. It is shown that due to the poorly soluble compound of CuCl being formed in acid media it is copper (I) that predominantly gets deposited with dichlorodiaminepalladium. Prior oxidation of the ammonia solution leads to a significantly reduced copper concentration in the deposited salt as CuCl2 is highly soluble. It is demonstrated that as the concentration of copper in the solution goes down from 0.72 to 0.125 g/l, a reduction in the copper concentration in dichlorodiaminepalladium is observed (from 0.008 to 0.001%). Through a drastic change in the salt deposition conditions, it was clearly shown that both the absorption mechanism of copper co-deposition in trans-[Pd(NH3)2Cl2] and occlusion are auxiliary. It was established that, in hydrochloric acid processing of ammonia solutions containing palladium and copper, once рН has reached 5–7 what precipitates first is copper in the form of poorly soluble hydroxide Cu(OH)2 and maybe also hydroxochloride. рН ~ 5 launches large-scale deposition of dichlorodiaminepalladium. Cu(OH)2 particles serve as salt nuclei helping [Pd(NH3)2Cl2] nucleation. As a result, the Cu(OH)2 microparticles find themselves in the cores of the dichlorodiam inepalladium cr ystals, so there are no conditions to enable the dissolution of copper hydroxides even at the final рН of 1.0. The salt deposition conditions were changed to prove that copper co-deposition with dichlorodiaminepalladium is mainly caused by the nonisomorphic inclusions of Cu(OH)2 in the trans-[Pd(NH3)2Cl2] crystals.

keywords Copper, palladium, deposition, dichlorodiaminepalladium, hydrochloric acid, ammonia solution, nucleation.

1. Schreier G., Edtmaier C. Separation of Ir, Pd and Rh from secondary Pt scrap by precipitation and calcinations. Hydrometallurgy. 2003. Vol. 68, No. 1–3. pp. 69–75.
2. Phetla T., Muzenda E., Belaid M. A Study of the Variables in the Optimisation of a Platinum Precipitation Process. International Journal of Chemical and Molecular Engineering. 2010. Vol. 4, No. 9. pp. 573–579.
3. Lottering C., Eksteen J. J., Steenekampt N. Precipitation of rhodium from a copper sulphate leach solution in the selenium/tellurium removal section of a base metal refinery. The Journal of The South African Institute of Mining and Metallurgy. 2012. Vol. 112, No. 4. pp. 287–294.
4. Tatarnikov A. V., Sokolskaya I., Shneerson Ya. M., Lapin A. Yu., Goncharov P. M. Treatment of Platinum Flotation Products. Platinum Metals Review. 2004. Vol. 48, No. 3. pp. 125–132.
5. Jha M. K., Lee J., Kim M., Jeong J., Kim B.-S., Kumar V. Hydrometallurgical recovery/recycling of platinum by the leaching of spent catalysts: A review. Hydrometallurgy. 2013. Vol. 133. pp. 23–32.
6. Mpinga C. N., Eksteen J. J., Aldrich C., Dyer L. Direct leach approaches to Platinum Group Metal (PGM) ores and concentrates: A review. Minerals Engineering. 2015. Vol. 78. pp. 93–113.
7. Edwards R. I. Refining of the platinum-group metals. JOM. 1976. Vol. 28, Iss. 8. pp. 4–9.
8. Sobral L. G. S., Granato M. Palladium: Extraction and refining. Minerals Engineering. 1992. Vol. 5, Iss. 1. pp. 17–25.
9. Bernardis F. L., Grant R. A., Sherrington D. C. A review of methods of separation of the platinum-group metals through their chloro-complexes. Reactive and Functional Polymers. 2005. Vol. 65, No. 3. pp. 205–217.
10. Sidorenko Yu. A. The practice of optimizing the processing of palladium materials at the open joint stock company “Gulidov Krasnoyarsk Non-Ferrous Metals Plant”. Rossiyskiy khimicheskiy zhurnal. 2006. Vol. 50, No. 4. pp. 6–12.
11. Belousov O. V., Belousova N. V., Ryumin A. I., Borisov R. V. Behavior of platinum metal concentrates under autoclave conditions. Russian Journal of Applied Chemistry. 2015. Vol. 88, No. 1. pp. 31–34.
12. Belousov O. V., Belousova N. V., Ryumin A. I., Borisov R. V. Refining of platinum-palladium concentrate under hydrothermal conditions. Russian Journal of Applied Chemistry. 2015. Vol. 88, No. 6. pp. 1078–1081.
13. Lidin R. A., Molochko V. A., Andreeva L. L. Chemical properties of inorganic substances. Moscow : KolosS, 2006. 480 p.
14. Inorganic chemistry. Ed. by Yu. D. Tretiakov. In 3 volumes. Vol. 3. Book 1. The chemistry of transition elements. Moscow : Akademiya, 2007. 352 p.
15. Monjaraz-Rodríguez A., Rodriguez-Bautist a M., Garza J., Zubillaga R. A., Vargas R. Coordination numbers in hydrated Cu (II) ions. Journal of Molecular Modeling. 2018. Vol. 24, No. 7. p. 187.
16. Hill S. J., Arowolo T. A., Butler O. T., Chenery S. R. N., Cook J. M., Cresser M. S., Miles D. L. Atomic spectrometry update. Environmental analysis. Journal of Analytical Atomic Spectrometry. 2002. Vol. 17, No. 3. pp. 284–317.
17. Resano M., Flórez M. R., Queralt I., Marguíc E. Determination of palladium, platinum and rhodium in used automobile catalysts and active pharmaceutical ingredients using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sample analysis. Spectrochimica Acta Part B: Atomic Spectroscopy. 2015. Vol. 105. pp. 38–46.

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