Vol. 25, No. 1 (2026), Proc26676 https://doi.org/10.24275/rmiq/Proc26676

Palladium solvent extraction process using a tertiary amine and isodecanol

 

Authors

G. Martínez-Ballesteros, J. L. Valenzuela-García, P. Guerrero-Germán, B. Valdez-Salas, R. Martínez-Peñuñuri

Abstract

The recovery of platinum-group metals from secondary resources has attracted much attention due to their high demand and low concentration in the Earth's crust. Metals can be recycled through hydrometallurgical processes that consist of leaching followed by an aqueous concentration and purification process, such as solvent extraction. This study investigated the separation of palladium via solvent extraction using chlorinated leaching solutions from waste electronic cards. To determine the best conditions for palladium extraction, a tertiary amine extractant was used, varying its concentration in the organic phase (8, 10, and 12% v/v) and isodecanol modifier at 10% v/v. In the aqueous phase, the pH (0.1, 0.5, 1, 1.5, and 2) and phase ratio were varied (0.8/1, 1/1, and 1.2/1), obtaining greater than 95% palladium extraction at pH=1.5 and an aqueous/organic ratio of 1.2/1, followed by 72% gold, 43% silver, and 30% platinum.

Keywords

Palladium, Solvent Extraction, Tertiary Amine, Isodecanol, Chloride Ions.

References
  • Aguayo, S., Valenzuela, J. L., Parga, J. R., Lewis, R. G., & Cruz, M. (2007). Continuous laboratory gold solvent extraction from cyanide solutions using LIX 79 reagent. Chemical Engineering & Technology: Industrial Chemistry‐Plant Equipment‐Process Engineering‐Biotechnology, 30(11), 1532-1536. https://doi.org/10.1002/ceat.200700202
  • Bernardis, F. L., Grant, R. A., & Sherrington, D. C. (2005). A review of methods of separation of the platinum-group metals through their chloro-complexes. Reactive and functional polymers, 65(3), 205-217. https://doi.org/10.1016/j.reactfunctpolym.2005.05.011
  • Birloaga, I., De Michelis, I., Ferella, F., Buzatu, M., & Vegliò, F. (2013). Study on the influence of various factors in the hydrometallurgical processing of waste printed circuit boards for copper and gold recovery. Waste management, 33(4), 935-941. https://doi.org/10.1016/j.wasman.2013.01.003
  • Cieszynska, A., & Wieczorek, D. (2018). Extraction and separation of palladium (II), platinum (IV), gold (III) and rhodium (III) using piperidine-based extractants. Hydrometallurgy, 175, 359-366. https://doi.org/10.1016/j.hydromet.2017.12.019
  • Cotton, F. A., Wilkinson, G., Murillo, C. A., & Bochmann, M. (1999). Advanced inorganic chemistry. John Wiley & Sons.
  • Duan, H., Li, J., Liu, Y., Yamazaki, N., & Jiang, W. (2012). Characterizing the emission of chlorinated/brominated dibenzo-p-dioxins and furans from low-temperature thermal processing of waste printed circuit board. Environmental pollution, 161, 185-191. https://doi.org/10.1016/j.envpol.2011.10.033
  • Galdi, G., Brotons-Rufes, A., & Costabile, C. (2026). Gold versus palladium catalyzed cross-coupling reactions: a DFT mechanistic study on the chemoselective arylation of alkyl nitriles. Molecular Catalysis, 588, 115524. https://doi.org/10.1016/j.mcat.2025.115524
  • Jadhav, U., & Hocheng, H. (2015). Hydrometallurgical recovery of metals from large printed circuit board pieces. Scientific reports, 5(1), 1-10.
  • Kordosky, G. A., Olafson, S. M., Lewis, R. G., Deffner, V. L., & House, J. E. (1987). A state-of-the-art discussion on the solvent extraction reagents used for the recovery of copper from dilute sulfuric acid leach solutions. Separation Science and Technology, 22(2-3), 215-232. https://doi.org/10.1080/01496398708068949
  • Lee, J.-c., Kurniawan, K., Kim, S., Nguyen, V. T., & Pandey, B. D. (2023). Ionic liquids-assisted solvent extraction of precious metals from chloride solutions. Separation & Purification Reviews, 52(3), 242-261. https://doi.org/10.1080/15422119.2022.2091458
  • Lee, J. Y., Raju, B., Kumar, B. N., Kumar, J. R., Park, H. K., & Reddy, B. R. (2010). Solvent extraction separation and recovery of palladium and platinum from chloride leach liquors of spent automobile catalyst. Separation and Purification Technology, 73(2), 213-218. https://doi.org/10.1080/15422119.2022.2091458
  • Lei, L. I., Wang, S., Wu, G., Wang, H., & Wang, S. (2020). Extraction of platinum and gold from copper anode slimes by a process of chlorinating roasting first and chlorinating leaching followed. Journal of Mining and Metallurgy, Section B: Metallurgy, 56(2), 193-202.
  • MacDonald, L., Zhang, D., & Karamalidis, A. (2024). Platinum group metals: Key solid phase adsorption technologies for separation from primary and secondary sources. Resources, Conservation and Recycling, 205, 107590. https://doi.org/10.1016/j.resconrec.2024.107590
  • Martinez-Ballesteros, G., Valenzuela-Garcia, J. L., Guerrero-German, P., Valdez-Salas, B., & Gomez-alvarez, A. (2024). Separation of palladium from waste electronic card leaching solutions by solvent extraction using a tertiary amine. Rev. Mex. Ing. Quim., 24(3). https://doi.org/10.24275/rmiq/Proc24380
  • Martinez-Ballesteros, G., Valenzuela-García, J. L., Gómez-Alvarez, A., Encinas-Romero, M. A., Mejía-Zamudio, F. A., Rosas-Durazo, A. d. J., & Valenzuela-Frisby, R. (2021). Recovery of Ag, Au, and Pt from printed circuit boards by pressure leaching. Recycling, 6(4), 67. https://doi.org/10.3390/recycling6040067
  • Nguyen, V. N. H., Song, S. J., & Lee, M. S. (2022). Separation of palladium and platinum metals by selective and simultaneous leaching and extraction with aqueous/non-aqueous solutions. Hydrometallurgy, 208, 105814. https://doi.org/10.1016/j.hydromet.2021.105814
  • Pianowska, K., Kluczka, J., Benke, G., Goc, K., Malarz, J., Ochmański, M., & Leszczyńska-Sejda, K. (2023). Solvent extraction as a method of recovery and separation of platinum group metals. Materials, 16(13), 4681. https://doi.org/10.3390/ma16134681
  • Rane, M. V., & Venugopal, V. (2006). Study on the extraction of palladium (II) and platinum (IV) using LIX 84I. Hydrometallurgy, 84(1-2), 54-59. https://doi.org/10.1016/j.hydromet.2006.04.005
  • Ritcey, G. M., & Ashbrook, A. W. (1984). Solvent Extraction: Principles and Applications to Process Metallurgy. Vol. 1. Elsevier.
  • Rovira, M., Cortina, J. L., & Sastre, A. M. (1999). Selective liquid-liquid extraction of palladium (II) from hydrochloric acid media by di-(2-ethylhexyl) thiophosphoric acid (DEHTPA). Solvent extraction and ion exchange, 17(2), 333-349. https://doi.org/10.1080/07366299908934616
  • Segura-Bailón, B., & Lapidus-Lavine, G. I mportance of chemical pretreatment for base metals remotion and its effect on the selective extraction of gold from Printed Circuits Boards (PCBs). Rev. Mex. Ing. Quim. 22: 1-17. https://doi.org/ 10.24275/rmi q/IA2335
  • Shoukry, M. M., & van Eldik, R. (2023). Equilibrium Studies on Pd (II)–Amine Complexes with Bio-Relevant Ligands in Reference to Their Antitumor Activity. International Journal of Molecular Sciences, 24(5), 4843. https://doi.org/10.3390/ijms24054843
  • Sole, K. C. (2008). Solvent extraction in the hydrometallurgical processing and purification of metals: process design and selected applications. In Solvent Extraction and Liquid Membranes (pp. 159-218). CRC press. https://doi.org/10.1201/9781420014112
  • Survey, U. S. G. (2020). Mineral commodity summaries 2020. US Geological Survey, 200. https://doi.org/10.3133/mcs2024
  • Torrejos, R. E. C., Nisola, G. M., Min, S. H., Han, J. W., Lee, S.-P., & Chung, W.-J. (2020). Highly selective extraction of palladium from spent automotive catalyst acid leachate using novel alkylated dioxa-dithiacrown ether derivatives. Journal of Industrial and Engineering Chemistry, 89, 428-435. https://doi.org/10.1016/j.jiec.2020.06.015
  • Torres, R., & Lapidus, G. T. (2016). Copper leaching from electronic waste for the improvement of gold recycling. Waste Management, 57, 131-139. https://doi.org/10.1016/j.wasman.2016.03.010
  • Uheida, A., Zhang, Y., & Muhammed, M. (2002). Selective extraction of palladium (II) from chloride solutions with nonylthiourea dissolved in chloroform. Solvent extraction and ion exchange, 20(6), 717-733. https://doi.org/10.1081/SEI-120016075
  • Wilson, A. M., Bailey, P. J., Tasker, P. A., Turkington, J. R., Grant, R. A., & Love, J. B. (2014). Solvent extraction: the coordination chemistry behind extractive metallurgy. Chemical Society Reviews, 43(1), 123-134. https://doi.org/10.1039/C3CS60275C
  • Xing, W. D., Lee, M. S., & Kim, Y. H. (2018). Separation of gold (III) from hydrochloric acid solution containing platinum (IV) and palladium (II) by solvent extraction with Cyanex 272 and LIX 63. Journal of industrial and engineering chemistry, 59, 328-334. https://doi.org/10.1016/j.jiec.2017.10.039