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1

Novel functional polymers for recovery of silver

Pilśniak-Rabiega Magdalena, Wolska Joanna

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 6

36--54

EN

In this study, the functional polymers containing heterocyclic ligands were synthesized by microwave modification of a crosslinked poly(vinylbenzyl chloride–divinylbenzene) matrix with 4-tertbutylpyridine, pyrrolidine, and 3-morpholinopropylamine. The sorbents were used to recover Ag(I) from the synthetic and real chloride solutions (4.00 mol/dm3 of NaCl, 0.100 mol/dm3 of HCl). The best Ag(I) sorption was achieved from synthetic and real chloride solutions in the case of pyrrolidine resin (16.2 and 16.7 mg/g, respectively). The sorption kinetic data were well fitted to the pseudo-first-order kinetic model. The degree of silver desorption was approximately 90% using a 1.0% potassium cyanide solution in a 0.50% hydrogen peroxide solution. All resins showed good selectivity for Ag(I) compared to Cu(II), Pb(II), Co(II), Ni(II), and Zn(II) in real chloride solution. On the basis of this study, it can be concluded that the obtained sorbents can be used to recover Ag from various sources such as ores, wastewater, and jewelry scraps.

2

Silver(I) recovery on sulfur-containing polymeric sorbents from chloride solutions

Pilśniak-Rabiega Magdalena, Wolska Joanna

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 6

290--310

EN

This work describes the preparation of functional polymers containing 2-mercapto-1-methylimidazole and guanylthiourea ligands from chemically modified vinylbenzyl chloride/divinylbenzene copolymer (VBC/DVB). The resins were used for the removal of Ag(I) from synthetic and real chloride solutions. The 2-mercapto-1-methylimidazole resin was highly selective towards Ag(I) in relation to Pb(II) from real chloride leaching solution. The resins were selective for Ag(I) from real chloride solution and they did not sorb chloride complexes of Co(II), Ni(II) and Zn(II). The sorption kinetic data were well fitted to the pseudo-first-order kinetic model. The degree of Ag(I) desorption was about 80% using 1% potassium cyanide solution in 0.5% hydrogen peroxide solution. Resins retain their capacity towards Ag(I) in five consecutive sorption/desorption cycles.

3

Selective removal of Ag(I) and Cu(II) by plasticizer membranes with n-(diethylthiophosphoryl)-aza[18]crown-6 as a carrier

Kolodziejska M., Kozlowski C., Kozlowska J., Ulewicz M.

Physicochemical Problems of Mineral Processing

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2014

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Vol. 50, iss. 1

237--247

EN

The competitive transport of equimolar mixtures of Ag(I) and Cu(II) ions from aqueous source phase (cMe = 0.001 mol/dm3) across polymer inclusion membranes PIMs with N-(diethylthiophosphoryl)aza[18]crown-6 as ion carriers, was studied. The influence of pH of source phase and metal concentration on an efficiency of silver(I) transport through polymer inclusion membranes containing cellulose triacetate as the support and o-nitrophenyl pentyl ether as the plasticizer was studied. The transport selectivity order for the PIM with N-(diethylthiophosphoryl)-aza[18]crown-6 was: Ag(I) >> Cu(II). The metal cations transport rate can be explained by size and nature of substituent in lariat ether molecule, which prefer formation of Ag(I) complex in the membrane phase.

4

The Influence of 2,2'-Bipyridine and 1-Amino-9,10-anthraquinone Side-Arm on Complexation Equilibria of Diaza-15-crown Ether in Various Solvents

Kira J., Ossowski T.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 12

2067-2078

EN

The influence of 2,2'-bipyridine and 1-amino-9,10-anthraquinone side-arm of diaza-15-crown ether on sil ver(I) complexation equilibria has been investigated in various non-aqueous solvents. The 2,2'-bipyridyl residue attached to the nitrogen atom of the macrocycle significantly controls the formation of 1:1 inclusion-type complexes by stabilizing silver ions in side the cavity. The addi tion of a sec ond 2,2'-bipyridine or 1-amino-9,10-anthraquinone slightly changes the stability constants of diaza-15-crown ether complexes and as well 1:2 metal-to-ligand complexes. Ag2L2+, Ag2L3 2+ and Ag2L3 2+ have been found, depending on the type of ligand and solvent species of higher complexity. This has been proved by both spectro photometric and potentiometric methods. Studies of substituted diaza-15-crown ethers were performed for comparison with an unsubstituted ligand.

5

An Influence of 2,2'-Bipyridine Side-Arm on Complexation Equilibria of Monoaza Crown Ethers in Various Solvents

Kira J., Ossowski T.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 6

1245-1254

EN

The influence of 2,2'-bipyridine side-arm of monoazacrown ethers on silver(I) complexation equilibria has been investigated in various non-aqueous solvents. The 2,2'-bipyridyl residue attached to nitrogen atom of the macrocycle significantly controls the formation of 1:1 inclusion-type complexes by stabilizing silver ion inside the cavity. For 1:2 metal-to-ligand complexes, 2,2'-bipyridine unit only slightly in creases stability constants of monoaza crown ether complexes. Opposite to the previous report, Ag2L2+com plex has not been observed; instead species of higher complexity, Ag2L3 2 have been found. Their presence has been proved by both spectrophotometry and potentiometry followed by advanced analysis. Studies of monoaza 12-crown ether were performed for comparison with 15- and 18-crown ethers.

6

Equilibria between Ag+ and Aza-Crown Ethers

Ossowski T., Trokowski R., Rogowska D, Kira J.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 3

345-353

EN

Complex-formation equilibria of silver(I) ions and aza-crown ethers and aliphatic amines were studied in acetonitrile, propylene carbonate, and methanol by the potentiometric method. It was found that AgL+ and AgL2 + species (L denoting the organic ligand) are formed. The stability constants of the complexes with crown ethers are greater compared to those with amines. It was found that solvent composition and cavity size of macrocyclic polyethers influence significantly the stability constants of the complexes formed. The difference in stability constants for various crown polyethers is discussed in terms of possible structure of the complexes.

7

Correlation Between temperature Coefficients of Ag+L Cryptate Stability Constant and of Ag/Ag+ Electrode Potential

Lewandowski A., Galiński M.

Polish Journal of Chemistry

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1999

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Vol. 73, nr 12

1987-1994

EN

The temperature coefficients, dlogK/dT, of the stability constants of Ag+ complexes with cryptands 221 and 222 were obtained directly from van't Hoff linear plots logK=a+bT-1 in 10 aprotic solvents: acetone, acetobitrile, propanenitrile, butyronitrile, benzonitrile.