scholarly journals Recovery of Palladium(II) and Platinum(IV) in Novel Extraction Systems

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 285
Author(s):  
Zuzanna Wiecka ◽  
Martyna Rzelewska-Piekut ◽  
Irmina Wojciechowska ◽  
Karolina Wieszczycka ◽  
Magdalena Regel-Rosocka
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Organic Phase ◽  
Alkyl Chain ◽  
Platinum Metal ◽  
Platinum Group Metals ◽  
Component Mixture ◽  
Quaternary Pyridinium Salts ◽  
Liquid Liquid Extraction ◽  
Stripping Efficiency

Recovery of platinum group metals (PGM) from complex aqueous solutions generated as a result of leaching of various spent materials (e.g., spent automotive converters) is a vital issue in the context of the circular economy. In this study pyridinium derivatives containing an imidoamide or imine moiety (i.e., 3-[1-(2-ethylhexyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)ethane]-1-propylpyridinium chloride and 4-[1-amine(2-ethylhexyloxyimine)]-1-propylpyridinium chloride) are proposed as novel extractants for recovery of palladium(II) and platinum(IV) from model chloride aqueous solutions. The results of liquid-liquid extraction from one-component solutions of palladium(II) or platinum(IV) showed that quaternary pyridinium salts can be used as effective extractants for platinum metal ions. Moreover, PGM extraction from a two-component mixture proved no evident selectivity in the transfer of one of the metal ions to the organic phase. As the best extractant among the investigated ones, D3EI-PrCl (with straight alkyl chain at substituent) can be pointed out, however, problems with effective stripping or phase disengagement after stripping should be indicated as a drawback of the organic phases used. Further investigation should focus on the improvement of the organic phase properties (e.g., increase in hydrophobicity of the extractants and addition of an organic phase modifier) towards stripping efficiency.

Transfer of divalent metal ions into the organic phase of the systems water–chloroform–ZnCl2–CdCl2–HgCl2–NaOH–(NaCl)–n-alkyltri(oxyethylene)carboxylic acid

1988 ◽  
Vol 66 (10) ◽  
pp. 2640-2646 ◽  
Author(s):  
Jerzy Strzelbicki ◽  
Witold Charewicz ◽  
Jorg Beger ◽  
Lutz Hinz
Keyword(s):  
Carboxylic Acid ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
Organic Phase ◽  
Metal Ion ◽  
Alkyl Chain ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Chemical Equilibria ◽  
Divalent Metal Ion

The influence of the length of an n-alkyl chain incorporated into the molecule of an n-alkyltri(oxyethylene) carboxylic acid of a general formula CnH(2n+1)(OCH2CH2)3OCH2CO2H(n = 6, 8, 10, and 12, respectively) on transfer of the zinc group element ions into chloroform was investigated. Metal ions were transferred from the aqueous solutions of ZnCl2, CdCl2, and HgCl2 at initial concentrations of 0.835 mM and 1.67 mM with, and without, added NaCl. From the aqueous solutions to which no NaCl was added, the selectivity of transfer of divalent metal ions into the organic phase was low.The selectivity of transfer of the divalent metal ions improved remarkably when NaCl was added to the aqueous phase due to the chemical equilibria involving complexation of the divalent metal ions by Cl−, OH−, and n-alkyltri(oxyethylene) carboxylic acid. In most systems (with NaCl added), Zn(II) was separated from Cd(II) and Hg(II). Less lipophilic n-alkyltri(oxyethylene) carboxylic acids (with a shorter n-alkyl chain incorporated) exhibited higher selectivity and efficiency as divalent metal ion carriers.

scholarly journals Origins of Clustering of Metalate-Extractant Complexes in Liquid-Liquid Extraction

2020 ◽  
Author(s):  
Srikanth Nayak ◽  
Raju R. Kumal ◽  
Zhu Liu ◽  
Baofu Qiao ◽  
Aurora Clark ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Organic Phase ◽  
Langmuir Monolayers ◽  
Strong Relationship ◽  
Liquid Extraction ◽  
Platinum Group Metals ◽  
Metal Loading ◽  
Liquid Liquid Extraction ◽  
Molecular Scale ◽  
Dynamics Simulations

Effective and energy efficient separation of precious and rare metals is very important for a variety of advanced technologies. Liquid-liquid extraction (LLE) is a relatively less energy intensive separation technique, widely used in separation of lanthanides, actinides, and platinum group metals (PGMs). In LLE, the distribution of an ion between an aqueous phase and an organic phase is determined by enthalpic (coordination interactions) and entropic (fluid reorganization) contributions. The molecular scale details of these contributions are not well understood. Preferential extraction of an ion from the aqueous phase is usually correlated with the resulting fluid organization in the organic phase, as the longer-range organization increases with metal loading. However, it is difficult to determine the extent to which organic phase fluid organization causes, or is caused by, metal loading. In this study, we demonstrate that two systems with the same metal loading may impart very different organic phase organization; and investigate the underlying molecular scale mechanism. Small angle X-ray scattering shows that the structure of a quaternary ammonium extractant solution in toluene is affected differently by the extraction of two metalates (octahedral PtCl<sub>6</sub><sup>2-</sup> and square-planar PdCl<sub>4</sub><sup>2-</sup>), although both are completely transferred into the organic phase. The aggregates formed by the metalate-extractant complexes (approximated as reverse micelles) exhibit more long-range order (clustering) with PtCl<sub>6</sub><sup>2-</sup> compared to that with PdCl<sub>4</sub><sup>2-</sup>. Vibrational sum frequency generation spectroscopy, and complimentary atomistic molecular dynamics simulations on model Langmuir monolayers, indicate that the two metalates affect the interfacial hydration structures differently. These results support a strong relationship between the organic phase organizational structure and different local hydration present within the aggregates of metalate-extractant complexes, which is independent of metalate concentration.

scholarly journals N,N’-Bis(salicylidene)ethylenediamine (Salen) as an Active Compound for the Recovery of Ni(II), Cu(II), and Zn(II) Ions from Aqueous Solutions

Membranes ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 60
Author(s):  
Katarzyna Witt ◽  
Daria Bożejewicz ◽  
Małgorzata A. Kaczorowska
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Active Compound ◽  
Metal Ion ◽  
High Resolution Mass Spectrometry ◽  
Separation Of Metal Ions ◽  
Ion Separation ◽  
Liquid Liquid Extraction ◽  
The Stability ◽  
Complexes With Metal Ions

In this paper, three main methods of metal ion separation, i.e., liquid–liquid extraction, transport across polymer inclusion membranes (PIMs), and sorption/desorption, are described. In all of them, N,N’-bis(salicylidene)ethylenediamine (salen) was used as an active compound, i.e., as an extractant or as a carrier for the recovery of Ni(II), Cu(II), or Zn(II) ions from aqueous solutions. In each case, the recovery was performed on a model solution, which contained only a single metal ion. The obtained results were compared with the author’s previous results for the separation of metal ions using β-diketones, since both β-diketones and salen form the so-called Werner-type complexes. Electrospray ionization high-resolution mass spectrometry (ESI-HRMS) was also applied to confirm the ability of the carrier to form complexes with metal ions in a solution. Moreover, spectrophotometry was used to determine the stability constant of the obtained complexes.

Origins of Clustering of Metalate-Extractant Complexes in Liquid-Liquid Extraction

2020 ◽  
Author(s):  
Srikanth Nayak ◽  
Raju R. Kumal ◽  
Zhu Liu ◽  
Baofu Qiao ◽  
Aurora Clark ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Organic Phase ◽  
Langmuir Monolayers ◽  
Strong Relationship ◽  
Liquid Extraction ◽  
Platinum Group Metals ◽  
Metal Loading ◽  
Liquid Liquid Extraction ◽  
Molecular Scale ◽  
Dynamics Simulations

Effective and energy efficient separation of precious and rare metals is very important for a variety of advanced technologies. Liquid-liquid extraction (LLE) is a relatively less energy intensive separation technique, widely used in separation of lanthanides, actinides, and platinum group metals (PGMs). In LLE, the distribution of an ion between an aqueous phase and an organic phase is determined by enthalpic (coordination interactions) and entropic (fluid reorganization) contributions. The molecular scale details of these contributions are not well understood. Preferential extraction of an ion from the aqueous phase is usually correlated with the resulting fluid organization in the organic phase, as the longer-range organization increases with metal loading. However, it is difficult to determine the extent to which organic phase fluid organization causes, or is caused by, metal loading. In this study, we demonstrate that two systems with the same metal loading may impart very different organic phase organization; and investigate the underlying molecular scale mechanism. Small angle X-ray scattering shows that the structure of a quaternary ammonium extractant solution in toluene is affected differently by the extraction of two metalates (octahedral PtCl<sub>6</sub><sup>2-</sup> and square-planar PdCl<sub>4</sub><sup>2-</sup>), although both are completely transferred into the organic phase. The aggregates formed by the metalate-extractant complexes (approximated as reverse micelles) exhibit more long-range order (clustering) with PtCl<sub>6</sub><sup>2-</sup> compared to that with PdCl<sub>4</sub><sup>2-</sup>. Vibrational sum frequency generation spectroscopy, and complimentary atomistic molecular dynamics simulations on model Langmuir monolayers, indicate that the two metalates affect the interfacial hydration structures differently. These results support a strong relationship between the organic phase organizational structure and different local hydration present within the aggregates of metalate-extractant complexes, which is independent of metalate concentration.

scholarly journals Origins of Clustering of Metalate-Extractant Complexes in Liquid-Liquid Extraction

2021 ◽  
Author(s):  
Srikanth Nayak ◽  
Raju R. Kumal ◽  
Zhu Liu ◽  
Baofu Qiao ◽  
Aurora Clark ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Organic Phase ◽  
Langmuir Monolayers ◽  
Strong Relationship ◽  
Liquid Extraction ◽  
Platinum Group Metals ◽  
Metal Loading ◽  
Liquid Liquid Extraction ◽  
Molecular Scale ◽  
Dynamics Simulations

Effective and energy efficient separation of precious and rare metals is very important for a variety of advanced technologies. Liquid-liquid extraction (LLE) is a relatively less energy intensive separation technique, widely used in separation of lanthanides, actinides, and platinum group metals (PGMs). In LLE, the distribution of an ion between an aqueous phase and an organic phase is determined by enthalpic (coordination interactions) and entropic (fluid reorganization) contributions. The molecular scale details of these contributions are not well understood. Preferential extraction of an ion from the aqueous phase is usually correlated with the resulting fluid organization in the organic phase, as the longer-range organization increases with metal loading. However, it is difficult to determine the extent to which organic phase fluid organization causes, or is caused by, metal loading. In this study, we demonstrate that two systems with the same metal loading may impart very different organic phase organization; and investigate the underlying molecular scale mechanism. Small angle X-ray scattering shows that the structure of a quaternary ammonium extractant solution in toluene is affected differently by the extraction of two metalates (octahedral PtCl<sub>6</sub><sup>2-</sup> and square-planar PdCl<sub>4</sub><sup>2-</sup>), although both are completely transferred into the organic phase. The aggregates formed by the metalate-extractant complexes (approximated as reverse micelles) exhibit more long-range order (clustering) with PtCl<sub>6</sub><sup>2-</sup> compared to that with PdCl<sub>4</sub><sup>2-</sup>. Vibrational sum frequency generation spectroscopy, and complimentary atomistic molecular dynamics simulations on model Langmuir monolayers, indicate that the two metalates affect the interfacial hydration structures differently. Further, the interfacial hydration is correlated with water extraction into the organic phase. These results support a strong relationship between the organic phase organizational structure and different local hydration present within the aggregates of metalate-extractant complexes, which is independent of metalate concentration.

Wastes generated by automotive industry – Spent automotive catalysts

2018 ◽  
Vol 3 (8) ◽  
Author(s):  
Martyna Rzelewska ◽  
Magdalena Regel-Rosocka
Keyword(s):  
Metal Ions ◽  
Precious Metals ◽  
Point Of View ◽  
Platinum Group Metals ◽  
Valuable Metal ◽  
Automotive Catalysts ◽  
Secondary Sources ◽  
Liquid Liquid Extraction ◽  
Liquid Phases ◽  
Spent Catalysts

Abstract Rhodium, ruthenium, palladium, and platinum are classified as platinum group metals (PGM). A demand for PGM has increased in recent years. Their natural sources are limited, therefore it is important, and both from economical and environmental point of view, to develop effective process to recover PGM from waste/secondary sources, such as spent automotive catalysts. Pyrometallurgical methods have always been used for separation of PGM from various materials. However, recently, an increasing interest in hydrometallurgical techniques for the removal of precious metals from secondary sources has been noted. Among them, liquid-liquid extraction by contacting two liquid phases: aqueous solution of metal ions and organic solution of extractant is considered an efficient technique to separate valuable metal ions from solutions after leaching from spent catalysts.

Chitosan-based Magnetic Composites - Efficient Adsorbents for Removal of Pb(II) and Cu(II) from Aqueous Mono and Bicomponent Solutions

2018 ◽  
Vol 69 (9) ◽  
pp. 2323-2330 ◽  
Author(s):  
Daniela C. Culita ◽  
Claudia Maria Simonescu ◽  
Rodica Elena Patescu ◽  
Nicolae Stanica
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Chemical Properties ◽  
Order Kinetic ◽  
Mass Ratio ◽  
Magnetic Adsorbent ◽  
Magnetic Composites ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Physical And Chemical

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.

Comparison of the fixation of several metal ions onto a low-cost biopolymer

2002 ◽  
Vol 2 (5-6) ◽  
pp. 217-224 ◽  
Author(s):  
Z. Reddad ◽  
C. Gérente ◽  
Y. Andrès ◽  
P. Le Cloirec
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Low Cost ◽  
Operating Conditions ◽  
Order Kinetic ◽  
Adsorption Mechanisms ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Beet Pulp ◽  
Removal Of Metal Ions

In the present work, sugar beet pulp, a common waste from the sugar refining industry, was studied in the removal of metal ions from aqueous solutions. The ability of this cheap biopolymer to sorb several metals namely Pb2+, Cu2+, Zn2+, Cd2+ and Ni2+ in aqueous solutions was investigated. The metal fixation capacities of the sorbent were determined according to operating conditions and the fixation mechanisms were identified. The biopolymer has shown high elimination rates and interesting metal fixation capacities. A pseudo-second-order kinetic model was tested to investigate the adsorption mechanisms. The kinetic parameters of the model were calculated and discussed. For 8 × 10-4 M initial metal concentration, the initial sorption rates (v0) ranged from 0.063 mmol.g-1.min-1 for Pb2+ to 0.275 mmol.g-1.min-1 for Ni2+ ions, with the order: Ni2+ &gt; Cd2+ &gt; Zn2+ &gt; Cu2+ &gt; Pb2+. The equilibrium data fitted well with the Langmuir model and showed the following affinity order of the material: Pb2+ &gt; Cu2+ &gt; Zn2+ &gt; Cd2+ &gt; Ni2+. Then, the kinetic and equilibrium parameters calculated qm and v0 were tentatively correlated to the properties of the metals. Finally, equilibrium experiments in multimetallic systems were performed to study the competition of the fixation of Pb2+, Zn2+ and Ni2+ cations. In all cases, the metal fixation onto the biopolymer was found to be favourable in multicomponent systems. Based on these results, it is demonstrated that this biosorbent represents a low-cost solution for the treatment of metal-polluted wastewaters.

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