本研究以濕式冶金技術進行廢棄車用觸媒轉換器之貴金屬資源再生，實驗主要分為四大部分，第一部分為材料基本特性分析，依據表面特性分析、晶體結構分析與化學成分分析之結果，規劃整體研究範疇與實驗設計。再藉由第二部分加壓酸溶浸漬將貴金屬溶解至水溶液中，並探討不同條件下金屬浸漬率得到最佳浸漬溶出參數，鈀、鉑、銠之浸漬效率皆可達到98%以上。
第三部分為金屬分離、純化之研究，以溶媒萃取法為本研究提純貴金屬之核心技術，並透過實驗數據計算分配比(Distribution ratio)、分離係數(Separation factor)、萃取率(Extraction percentage)做為判斷指標。使用三正辛胺(Tri-n-Octylamine)進行萃取分離，將[PdCl4]2-、[PtCl6]2-轉移至有機相，[RhCl6]3-則留在萃餘液中。接續使用硫脲/鹽酸系統與過氯酸進行兩階段反萃取，以化學反應速率不同之特性可先將[PdCl4]2-反萃取至水相，而[PtCl6]2-則使用過氯酸溶液做為反萃取藥劑。藉由萃取和反萃取程序可使三種貴金屬達到良好的分離效果，鈀萃取率和反萃率分別為74.9%、94.9%；鉑萃取率和反萃率分別為95.9%、99.1%。銠的損耗率為1.4%。
第四部分為金屬化合物析出之研究，本階段將分為三種方式，以氨水進行鈀的沉澱析出；利用氯化銨/氨水水溶液使鉑產生沉澱；銠使用聯胺/氫氧化鈉水溶液進行還原析出，得到之產物分別為二氯二氨鈀、氯鉑酸銨及銠黑，其純度分別為99.48%、99.36%、99.85%。

Compared to natural resources, automotive catalysts contain over 100 times the concentrations of platinum group metals (PGMs). The catalysts were initially crashed into powder in this study. Furthermore, sieving and mixing were adopted to ensure the homogeneity of the samples. Hydrometallurgy was then applied to recover palladium, platinum, and rhodium. Employing hydrochloric acid and hydrogen peroxide to do pressure leaching is an effective way to dissolve precious metals in the catalysts. After that, Tri-n-octylamine (TOA) was used to separate palladium and platinum from rhodium in the extraction step. Thiourea/HCl and perchloric acid were stripping agents for Pd and Pt, respectively. The metal compounds were subsequently recovered by chemical precipitation and hydrazine reduction. [PtCl6]2- reacted with ammonium chloride and ammonia to produce (NH4)2PtCl6; [PdCl4]2- reacted with ammonia to produce (NH3)2PdCl2; [RhCl6]3- was directly reduced to metallic state. In brief, this research investigated the optimal parameters for leaching and solvent extraction procedures. The purities of (NH4)2PtCl6, (NH3)2PdCl2, and Rh were 99.48%, 99.36%, and 99.85%.

[1] S. Sun, C. Jin, W. He, G. Li, H. Zhu, and J. Huang, A review on management of waste three-way catalysts and strategies for recovery of platinum group metals from them. Journal of Environmental Management, 2022. 305.
[2] I. Yakoumis, M. Panou, A. M. Moschovi, and D. Panias, Recovery of platinum group metals from spent automotive catalysts: A review. Cleaner Engineering and Technology, 2021. 3.
[3] Mineral commodity summaries 2023, in Mineral Commodity Summaries. 2023: Reston, VA. p. 210.
[4] R. Granados-Fernández, M. A. Montiel, S. Díaz-Abad, M. A. Rodrigo, and J. Lobato, Platinum recovery techniques for a circular economy. Catalysts, 2021. 11(8).
[5] C. H. Kim, S. I. Woo, and S. H. Jeon, Recovery of platinum-group metals from recycled automotive catalytic converters by carbochlorination. Industrial and Engineering Chemistry Research, 2000. 39(5): p. 1185-1192.
[6] K. C. Chiang, K. L. Chen, C. Y. Chen, J. J. Huang, Y. H. Shen, M. Y. Yeh, and F. F. Wong, Recovery of spent alumina-supported platinum catalyst and reduction of platinum oxide via plasma sintering technique. Journal of the Taiwan Institute of Chemical Engineers, 2011. 42(1): p. 158-165.
[7] O. Lanaridi, S. Platzer, W. Nischkauer, J. H. Betanzos, A. U. Iturbe, C. Del Rio Gaztelurrutia, L. Sanchez-Cupido, A. Siriwardana, M. Schnürch, A. Limbeck, T. Konegger, and K. Bica-Schröder, Benign recovery of platinum group metals from spent automotive catalysts using choline-based deep eutectic solvents. Green Chemistry Letters and Reviews, 2022. 15(2): p. 404-414.
[8] Wei-Sheng Chen and Jie-Yu Yang, Concentrating and Dissolving Platinum Group Metals from Copper Anode Slime. International Journal of Materials, Mechanics and Manufacturing, 2019. 7: p. 245-249.
[9] A. Van den Bossche, N. Rodriguez Rodriguez, S. Riaño, W. Dehaen, and K. Binnemans, Dissolution behavior of precious metals and selective palladium leaching from spent automotive catalysts by trihalide ionic liquids. RSC Advances, 2021. 11(17): p. 10110-10120.
[10] M A Barakat, G A EL-Mahdy, M Hegazy, and F Zahran, Hydrometallurgical recovery of nano-palladium from spent catalyst. The Open Mineral Processing Journal, 2009. 2(1).
[11] J. de Oliveira Demarco, J. Stefanello Cadore, H. M. Veit, H. Bremm Madalosso, E. Hiromitsu Tanabe, and D. Assumpção Bertuol, Leaching of platinum group metals from spent automotive catalysts using organic acids. Minerals Engineering, 2020. 159.
[12] B. Xu, Y. Chen, Y. Zhou, B. Zhang, G. Liu, Q. Li, Y. Yang, and T. Jiang, A Review of Recovery of Palladium from the Spent Automobile Catalysts. Metals, 2022. 12(4).
[13] 進 清水 and 幸宏 村岸, 絵とき貴金属利用技術基礎のきそ. Machine design series. 2011: 日刊工業新聞社.
[14] L. Xolo, P. Moleko-Boyce, H. Makelane, N. Faleni, and Z. R. Tshentu, Status of recovery of strategic metals from spent secondary products. Minerals, 2021. 11(7).
[15] S. Kolbadinejad and A. Ghaemi, Recovery and extraction of platinum from spent catalysts: A review. Case Studies in Chemical and Environmental Engineering, 2023. 7.
[16] Joyce A. Ober, Mineral commodity summaries 2017, in Mineral Commodity Summaries. 2017: Reston, VA. p. 202.
[17] Joyce A. Ober, Mineral commodity summaries 2018, in Mineral Commodity Summaries. 2018: Reston, VA. p. 204.
[18] Mineral Commodity Summaries 2019, in Mineral Commodity Summaries. 2019: Reston, VA.
[19] Mineral commodity summaries 2020, in Mineral Commodity Summaries. 2020: Reston, VA. p. 204.
[20] Mineral commodity summaries 2021, in Mineral Commodity Summaries. 2021: Reston, VA. p. 200.
[21] Mineral commodity summaries 2022, in Mineral Commodity Summaries. 2022: Reston, VA. p. 202.
[22] H. Tang, Z. Peng, Z. Li, Y. Ma, J. Zhang, L. Ye, L. Wang, M. Rao, G. Li, and T. Jiang, Recovery of platinum-group metals from spent catalysts by microwave smelting. Journal of Cleaner Production, 2021. 318.
[23] H. Tang, Z. Peng, R. Tian, L. Ye, J. Zhang, M. Rao, and G. Li, Recycling of platinum-group metals from spent automotive catalysts by smelting. Journal of Environmental Chemical Engineering, 2022. 10(6).
[24] M. Benson, C. R. Bennett, J. E. Harry, M. K. Patel, and M. Cross, The recovery mechanism of platinum group metals from catalytic converters in spent automotive exhaust systems. Resources, Conservation and Recycling, 2000. 31(1): p. 1-7.
[25] R. Panda, M. K. Jha, and D. D. Pathak. Commercial processes for the extraction of platinum group metals (PGMs). in Minerals, Metals and Materials Series. 2018.
[26] Georgios Kolliopoulos, Efthymios Balomenos, Ioanna Giannopoulou, Iakovos Yakoumis, and Dimitrios Panias, Behavior of platinum group metals during their pyrometallurgical recovery from spent automotive catalysts. Open Access Lib. J, 2014. 1: p. 1-9.
[27] Saša Z Ivanović, Vlastimir K Trujuć, Milan D Gorgievski, Ljubiša D Mišić, and Dragana S Božić. Removal of platinum group metals (PGMs) from the spent automobile catalyst by the pyrometallurgical process. in 15th International Research/Expert Conference” Trends in the Development of Machinery and Associated Technology”. 2011. Citeseer.
[28] 赵家春, 崔浩, 保思敏, 童伟锋, 吴跃东, and 董海刚, 铜捕集法回收铂族金属的理论及实验研究. 中国有色金属学报, 2019. 12.
[29] M. Saternus, A. Fornalczyk, W. Gąsior, A. Dębski, and S. Terlicka, Modifications and improvements to the collector metal method using an mhd pump for recovering platinum from used car catalysts. Catalysts, 2020. 10(8).
[30] Z. Peng, Z. Li, X. Lin, H. Tang, L. Ye, Y. Ma, M. Rao, Y. Zhang, G. Li, and T. Jiang, Pyrometallurgical Recovery of Platinum Group Metals from Spent Catalysts. JOM, 2017. 69(9): p. 1553-1562.
[31] C. Liu, S. Sun, X. Zhu, and G. Tu, Metals smelting-collection method for recycling of platinum group metals from waste catalysts: A mini review. Waste Management and Research, 2021. 39(1): p. 43-52.
[32] M. H. Morcali, A new approach to recover platinum-group metals from spent catalytic converters via iron matte. Resources, Conservation and Recycling, 2020. 159.
[33] Y. Ding, H. Zheng, S. Zhang, B. Liu, B. Wu, and Z. Jian, Highly efficient recovery of platinum, palladium, and rhodium from spent automotive catalysts via iron melting collection. Resources, Conservation and Recycling, 2020. 155.
[34] 蒋开喜, 加压湿法冶金. 2016: 冶金工业出版社.
[35] L. Pietrelli and D. Fontana, Automotive spent catalysts treatment and platinum recovery. International Journal of Environment and Waste Management, 2013. 11(2): p. 222-232.
[36] Martyna Rzelewska-Piekut, Dominik Paukszta, and Magdalena Regel-Rosocka, Hydrometallurgical recovery of platinum group metals from spent automotive converters. Physicochemical Problems of Mineral Processing, 2021. 57.
[37] B. A. Masry, M. M. Zeid, A. T. Kassem, H. G. Noweir, E. A. Saad, and J. A. M. Daoud, Liquid-liquid extraction and recovery of Pd(II) from nitric acid medium using green diesel as extractant. Journal of Physical Science, 2018. 29(2): p. 25-48.
[38] Ulziikhuu Otgonbayar, Lesia Sandig-Predzymirska, Alexandra Thiere, and Alexandros Charitos, Process Development for the Separation of Pt, Ru, and Ir by Solvent Extraction. World of Metallurgy - ERZMETALL, 2023. 76(3): p. 177-183.
[39] M. L. Firmansyah, F. Kubota, and M. Goto, Selective recovery of platinum group metals from spent automotive catalysts by leaching and solvent extraction. Journal of Chemical Engineering of Japan, 2019. 52(11): p. 835-842.
[40] R. Gaita and S. J. Al-Bazi, An ion-exchange method for selective separation of palladium, platinum and rhodium from solutions obtained by leaching automotive catalytic converters. Talanta, 1995. 42(2): p. 249-255.
[41] Jeong-yi Moon, Syouhei Nishihama, and Kazuharu Yoshizuka, Recovery of Platinum and Palladium from Spent Automobile Catalyst by Solvent-Impregnated Resins. Solvent Extraction and Ion Exchange, 2018. 36(5): p. 470-479.
[42] P. Moleko-Boyce, H. Makelane, and Z. R. Tshentu, Recovery of Platinum Group Metals from Leach Solutions of Spent Catalytic Converters Using Custom-Made Resins. Minerals, 2022. 12(3).
[43] K. Matsumoto, Y. Sezaki, S. Yamakawa, Y. Hata, and M. Jikei, Selective and mutual separation of palladium (II), platinum (IV), and rhodium (III) using aliphatic primary amines. Metals, 2020. 10(3).
[44] K. Matsumoto, S. Yamakawa, Y. Sezaki, H. Katagiri, and M. Jikei, Preferential Precipitation and Selective Separation of Rh(III) from Pd(II) and Pt(IV) Using 4-Alkylanilines as Precipitants. ACS Omega, 2019. 4(1): p. 1868-1873.
[45] J Siame and H Kasaini. Selective precipitation of Pt and base metals in liquid-liquid chloride systems. in Conference on Chemical and Environmental Engineering (ICCEE'2013) April. 2013.
[46] H. B. Trinh, J. C. Lee, R. R. Srivastava, and S. Kim, Total recycling of all the components from spent auto-catalyst by NaOH roasting-assisted hydrometallurgical route. Journal of Hazardous Materials, 2019. 379.
[47] I. H. Choi, G. Moon, J. Y. Lee, and R. K. Jyothi, Alkali fusion using sodium carbonate for extraction of vanadium and tungsten for the preparation of synthetic sodium titanate from spent SCR catalyst. Scientific Reports, 2019. 9(1).
[48] N. Bahaloo-Horeh and S. M. Mousavi, Efficient extraction of critical elements from end-of-life automotive catalytic converters via alkaline pretreatment followed by leaching with a complexing agent. Journal of Cleaner Production, 2022. 344.
[49] J. Spooren and T. Abo Atia, Combined microwave assisted roasting and leaching to recover platinum group metals from spent automotive catalysts. Minerals Engineering, 2020. 146.
[50] A. M. Yousif, Recovery and then individual separation of platinum, palladium, and rhodium from spent car catalytic converters using hydrometallurgical technique followed by successive precipitation methods. Journal of Chemistry, 2019. 2019.
[51] E. Prasetyo and C. Anderson, Platinum group elements recovery from used catalytic converters by acidic fusion and leaching. Metals, 2020. 10(4).
[52] Suzana Dragulovic, Mile Dimitrijevic, Ana Kostov, and Smiljana Jakovljevic. Recovery of platinum group metals from spent automotive catalyst. in 12th International Research/Expert Conference: Trends in the Development of Machinery and Associated Technology, TMT. 2008. Citeseer.
[53] M. Asadzadeh and Seyed Ali Akbar Sajadi, Separation and Recovery of Platinum and Palladium from Spent Petrochemical Catalysts Using Activated Carbon, Analysis of Two Kind of Most Used Catalysts in Petro Chemistry. Iranian Journal of Chemistry and Chemical Engineering (IJCCE), 2018. 37(5): p. 9-18.
[54] S. Harjanto, Y. Cao, A. Shibayama, I. Naitoh, T. Nanami, K. Kasahara, Y. Okumura, K. Liu, and T. Fujita, Leaching of Pt, Pd and Rh from automotive catalyst residue in various chloride based solutions. Materials Transactions, 2006. 47(1): p. 129-135.
[55] P. Trucillo, A. Lancia, D. D'Amore, B. Brancato, and F. Di Natale, Selective leaching of precious metals from electrical and electronic equipment through hydrometallurgical methods. Chemical Engineering Transactions, 2021. 86: p. 1039-1044.
[56] J. Xia and A. Ghahreman, Platinum group metals recycling from spent automotive catalysts: metallurgical extraction and recovery technologies. Separation and Purification Technology, 2023. 311.
[57] C. Saguru, S. Ndlovu, and D. Moropeng, A review of recent studies into hydrometallurgical methods for recovering PGMs from used catalytic converters. Hydrometallurgy, 2018. 182: p. 44-56.
[58] H Pasdar, J Fallah, R Marandi, Sh Daneshpajuh, and H Hajmohammadi, Extraction and Recovery of Platinum Solution with tri n-octylAmine and Determination by Inductively Coupled Plasma (ICP). Journal of Applied Chemical Research, 2011. 17: p. 37-40.
[59] M. A. Barakat and M. H. H. Mahmoud, Recovery of platinum from spent catalyst. Hydrometallurgy, 2004. 72(3-4): p. 179-184.
[60] J. Wang, L. Liu, W. Xu, H. Liu, G. Xu, K. Huang, F. Yu, and G. Huang, Separation of Pd and Pt from highly acidic leach liquor of spent automobile catalysts with monothio-Cyanex 272 and trioctylamine. International Journal of Minerals, Metallurgy and Materials, 2023. 30(5): p. 877-885.
[61] H Yoshizawa, Koichiro Shiomori, Shuji Yamada, Yoshinari Baba, Yoshinobu Kawano, Kazuo Kondo, Kazuya Ijichi, and Yasuo Hatate, Solvent extraction of platinum (IV) from aqueous acidic chloride media with tri-n-octylamine in toluene. Solvent Extraction Research and Development, 1997. 1997(4): p. 157-166.
[62] A. Jaree and N. Khunphakdee, Separation of concentrated platinum(IV) and rhodium(III) in acidic chloride solution via liquid-liquid extraction using tri-octylamine. Journal of Industrial and Engineering Chemistry, 2011. 17(2): p. 243-247.
[63] A. P. Paiva, F. V. Piedras, P. G. Rodrigues, and C. A. Nogueira, Hydrometallurgical recovery of platinum-group metals from spent auto-catalysts – Focus on leaching and solvent extraction. Separation and Purification Technology, 2022. 286.
[64] T. H. Nguyen, C. H. Sonu, and M. S. Lee, Separation of platinum(IV) and palladium(II) from concentrated hydrochloric acid solutions by mixtures of amines with neutral extractants. Journal of Industrial and Engineering Chemistry, 2015. 32: p. 238-245.
[65] B. Gupta and I. Singh, Extraction and separation of platinum, palladium and rhodium using Cyanex 923 and their recovery from real samples. Hydrometallurgy, 2013. 134-135: p. 11-18.
[66] H. T. Truong, M. S. Lee, and G. Senanayake, Separation of Pt(IV), Rh(III) and Fe(III) in acid chloride leach solutions of glass scraps by solvent extraction with various extractants. Hydrometallurgy, 2018. 175: p. 232-239.
[67] Naoto Takeno, Atlas of Eh-pH diagrams. Geological survey of Japan open file report, 2005. 419: p. 102.
[68] René Rumpold and Jürgen Antrekowitsch. Recycling of platinum group metals from automotive catalysts by an acidic leaching process. in Proceedings of the 5th International Platinum Conference, Sun City, South Africa, The Southern African Institute of Mining and Metallurgy. 2012.
[69] F. L. Bernardis, R. A. Grant, and D. C. Sherrington, A review of methods of separation of the platinum-group metals through their chloro-complexes. Reactive and Functional Polymers, 2005. 65(3): p. 205-217.
[70] JIANMIN Yu, Solvent extraction chemistry of precious metals. Platinum Metals Rev, 2005. 49(4): p. 189.
[71] 余建民, 贵金属分离与精炼工艺学. 北京:化学工业出版. 2007.
[72] CD Wagner, AV Naumkin, A Kraut-Vass, JW Allison, CJ Powell, and JR Rumble Jr, NIST standard reference database 20, Version 3.4 (Web version). National Institute of Standards and Technology: Gaithersburg, MD, 2003. 20899.
[73] X. Wei, C. Liu, H. Cao, P. Ning, W. Jin, Z. Yang, H. Wang, and Z. Sun, Understanding the features of PGMs in spent ternary automobile catalysts for development of cleaner recovery technology. Journal of Cleaner Production, 2019. 239.
[74] D. Yang, Q. Yang, W. Ma, X. Ma, S. Wang, and Y. Lei, Characteristics of spent automotive catalytic converters and their effects on recycling platinum-group-metals and rare-earth-elements. Separation and Purification Technology, 2023. 308.
[75] T. Ge, J. D. He, L. Xu, Y. H. Xiong, L. Wang, X. W. Zhou, Y. P. Tian, and Z. Zhao, Recovery of platinum from spent automotive catalyst based on hydrometallurgy. Rare Metals, 2023. 42(4): p. 1118-1137.
[76] D. Jimenez De Aberasturi, R. Pinedo, I. Ruiz De Larramendi, J. I. Ruiz De Larramendi, and T. Rojo, Recovery by hydrometallurgical extraction of the platinum-group metals from car catalytic converters. Minerals Engineering, 2011. 24(6): p. 505-513.
[77] 蔡宏鑫, 結合濕法冶金及離子液體回收汽車廢觸媒轉化器中貴金屬之技術開發, in 環境工程研究所. 2016, 國立中山大學.
[78] S. Ilyas, R. R. Srivastava, H. Kim, and H. A. Cheema, Hydrometallurgical recycling of palladium and platinum from exhausted diesel oxidation catalysts. Separation and Purification Technology, 2020. 248.
[79] I. Birloaga and F. Vegliò, An innovative hybrid hydrometallurgical approach for precious metals recovery from secondary resources. Journal of Environmental Management, 2022. 307.
[80] M. K. Jha, D. Gupta, J. C. Lee, V. Kumar, and J. Jeong, Solvent extraction of platinum using amine based extractants in different solutions: A review. Hydrometallurgy, 2014. 142: p. 60-69.
[81] V. Mohdee, V. Parasuk, and U. Pancharoen, Synergistic effect of Thiourea and HCl on Palladium (II) recovery: An investigation on Chemical structures and thermodynamic stability via DFT. Arabian Journal of Chemistry, 2021. 14(7).