Extraction and separation of palladium(II), platinum(IV), gold(III) and rhodium(III) using piperidine-based extractants
Introduction
Technological processes all over the world show relentless demand for precious metals, in particular palladium (Pd), rhodium (Rh), platinum (Pt) and gold (Au). The demand is still increasing, as these metals have been for many years used as catalysts in the organic technology processes, as boosters in motor vehicle catalytic converter systems and recently as afterburners in modern, environmentally friendly domestic furnaces installations. Besides the application in vehicle catalytic converter systems, palladium is used mainly in dentistry, jewelry and electrical engineering. Palladium has been widely used in electronic applications on account of its electrical conductivity and durability. Palladium-containing components are used in virtually every type of electronic device, from basic consumer products to complex military hardware. In addition, platinum is also used in jewelry products, in inorganic chemical, petrochemical, electrical, glass industry, dentistry, it also is a good capital investment. The world supply and demand of palladium is presented in Fig. 1. (Hagelüken, 2006, Hagelüken and Corti, 2010, Matthey, n.d, Matthey, 2016). Recovery of precious metals from spent materials is very important to replenish a gap between the demand and the limited supply from natural resources. Recycling of waste materials, like electronic scraps or spent vehicle catalytic converter systems is perfectly legitimate, not only due to the impact that the ill-managed waste may have on the environment, but also because of its profitability in view of the possibility of recovery of valuable components, including precious metals.
Currently, the recovery of PGMs from natural and spent materials is carried out using traditional pyrometallurgical or hydrometallurgical methods. Hydrometallurgical processing of waste materials has been the area of the most intensive research in the field of wet techniques for the last two decades. The advantage of the wet methods is that they are more precise, predictable and easier to control. In addition, they do not require the use of complex and expensive equipment to ensure proper temperature and process conditions. A disadvantage of hydrometallurgy is formation of harmful to the environment solutions, which should be managed and if possible, reused. Hydrometallurgical processing can be broken down to three general steps: leaching, solution concentration, separation and purification (solvent extraction, adsorption and ion exchange) as well as metal recovery. Solvent extraction in hydrometallurgical processing is a suitable method for removal of PGMs from low concentrated sources and allows their separation and purification (Bernardis et al., 2005, Cui and Zhang, 2008, Iwakuma et al., 2008). Many different extractants have been investigated and proposed for palladium(II) extraction, including alkyl derivatives of 8-hydroxyquinoline (Cote and Demopoulos, 1994), hydroxyoximes and ketoximes (Cleare et al., 1981, Rane and Venugopal, 2006, Shen and Xue, 2007, Wisniewski and Szymanowski, 1996, Nguyen et al., 2016), dialkyl sulphides and sulphoxides (Pan and Zhang, 2009, Pan et al., 2008, Preston and du Preez, 2002, Zhu et al., 2006), organophosphorus extractants (Gupta and Singh, 2013, Men'shikov et al., 2009, Zhidkova et al., 2009), various kind of amide derivatives (Anpilogova et al., 2014, Huang et al., 2015, Ortet and Paiva, 2015, Paiva et al., 2014, Regel-Rosocka et al., 2007), and phosphonium ionic liquids (Cieszynska and Wisniewski, 2010, Cieszynska and Wisniewski, 2011, Cieszynska and Wisniewski, 2012). Also hydrophobic amines and quaternary ammonium salts have been used as extractants for recovery and separation of palladium ions. Extraction properties of amine depend on their structure and the type of substituent. The ability of simple amines to extract metal complexes with nitrates and halides increases in the order: primary < secondary < tertiary < quaternary (Belova et al., 2007, Lee et al., 2009, Najafi et al., 2015, Nguyen et al., 2015, Rovira et al., 1998, Swain et al., 2010). It is supposed that the heterocyclic amines, like N-alkylpiperidine, should exhibit comparable or better extraction properties of metal ions such as palladium(II), platinum(IV) and rhodium(III) than simple amines.
Looking for an extractant capable of fast extraction of palladium ions, we proposed to synthesize and test N-alkylpiperidines: N-decylpiperidine (P-C10), N-dodecylpiperidine (P-C12), N-tetradecylpiperidine (P-C14) and N-hexadecylpiperidine (P-C16). It is the aim of the work to establish the extraction abilities of the synthesized N-alkylpiperidines (P-C10, P-C12, P-C14 and P-C16) to extract palladium(II) from hydrochloric acid solutions of various concentrations. The selectivity of palladium(II) extraction over rhodium(III), platinum(IV) and gold(III) with the synthesized N-dodecylpiperidine (P-C12), in the presence of toluene, has been investigated.
Section snippets
Reagents
Commercial palladium chloride PdCl2 (99%, Avantor Performance Materials Poland S.A., Poland), platinum chloride PtCl4 (99%, Avantor Performance Materials Poland S.A., Poland), rhodium chloride RhCl3 (98%, Sigma-Aldrich, Poland), gold chloride AuCl3 (99%, Sigma-Aldrich, Poland) hydrochloric acid (analytically pure, 35–38%, Chempur, Poland), sulfuric acid (analytically pure, 95%, Chempur, Poland), nitric acid (analytically pure, 65%, Avantor Performance Materials Poland S.A., Poland), ammonium
Effect of contact time and HCl concentration
The effect of contact time on the palladium(II) extraction was studied by contacting the aqueous feed containing 1 mM Pd(II) in 0.1 M HCl with 2 mM P-C10, P-C12, P-C14 and P-C16 in the presence of toluene. The transfer of palladium(II) to N-alkylpiperidines examined as the organic phase was very fast. About 5 min was necessary to achieve the equilibrium of palladium(II) extraction, which is a great advantage of the examined reagents (Fig. 3). The efficiency of palladium(II) extraction with the
Conclusions
Four N-alkylpiperidines (P-C10, P-C12, P-C14 and P-C16) have been synthesized and their ability to extract palladium(II) from hydrochloric acid solutions was studied. The results presented in this paper prove that N-alkylpiperidines can be used as extractants for the removal of palladium ions from chloride media. The efficiency of palladium(II) extraction depends on HCl concentration, extractant concentration, type of extractant diluent, metal concentration and contact time of the phases. The
References (41)
- et al.
A review of methods of separation of the platinum-group metals through their chloro-complexes
React. Funct. Polym.
(2005) - et al.
Extraction of palladium(II) from chloride solutions with Cyphos®IL 101/toluene mixtures as novel extractant
Sep. Purif. Technol.
(2010) - et al.
Selective extraction of palladium(II) from hydrochloric acid solutions with phosphonium extractants
Sep. Purif. Technol.
(2011) - et al.
Extractive recovery of palladium(II) from hydrochloric acid solutions with Cyphos®IL 104
Hydrometallurgy
(2012) - et al.
Metallurgical recovery of metals from electronic waste: a review
J. Hazard. Mater.
(2008) - et al.
Extraction and separation of platinum, palladium and rhodium using Cyanex 923 and their recovery from real samples
Hydrometallurgy
(2013) - et al.
Extraction of palladium(II) from nitric acid solutions with diglycolthioamide
Hydrometallurgy
(2015) - et al.
Studies of removal of platinum(IV) ion microquantities from the model solutions of aluminium, copper, iron, nickel and zinc chloride macroquantities on the anion exchanger Duolite S 37
J. Hazard. Mater.
(2006) - et al.
Liquid-liquid extraction/separation of platinum(IV) and rhodium(III) from acidic chloride solutions using tri-iso-octylamine
J. Hazard. Mater.
(2009) - et al.
Separation of platinum(IV) and palladium(II) from concentrated hydrochloric acid solutions by mixtures of amines with neutral extractants
J. Ind. Eng. Chem.
(2015)
Separation of Pt(IV), Rh(II) and Ir(III) from concentrated hydrochloric acid solutions by solvent extraction
Hydrometallurgy
Development of tertiary thioamide derivatives to recovery palladium(II) from simulated complex chloride solutions
Hydrometallurgy
Solvent extraction and separation of palladium(II) and platinum(IV) from hydrochloric acid medium with dibutyl sulfoxide
Miner. Eng.
Study on the extraction of palladium(II) and platinum(IV) using LIX 84I
Hydrometallurgy
Selective extraction of palladium(II) from hydrochloric acid solutions with piridinecarboxamides and ACORGA®CLX50
Sep. Purif. Technol.
Recovery of palladium(II) from hydrochloric acid solutions using impregnated resins containing Alamine 336
React. Funct. Polym.
Recovery palladium, gold and platinum from hydrochloric acid solution using 2-hydroxy-4-sec-octanol diphenylketoxime
Sep. Purif. Technol.
Separation of platinum and palladium from chloride solution by solvent extraction using Alamine 300
Hydrometallurgy
Thiol functionalizedmesoporous silicas for selective adsorption of precious metals
Miner. Eng.
The pilot test of Pt-Pd and Pt-Rh feeds extracted and separated with new sulfoxide extractant
Rare Metals
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