Separation of gold(III) ions from copper(II) and zinc(II) ions using thiourea–formaldehyde or urea–formaldehyde chelating resins

Abstract

Thiourea-formaldehyde (TF) and ureaformaldehyde (UF) chelating resins were synthesized and these resins were used in the separation of gold(III) ions from copper(II) and zinc(II) base metal ions. In the experimental studies, the effect of acidity on gold(III) uptake and gold(III) adsorption capacities by batch method, and loading and elution profiles of gold(III) ions, gold(III), copper(II), and zinc(II), dynamic adsorption capacities and the stability tests of TF and UF resins by column method were examined. By batch method, the optimum acidities were found as pH 2 and 0.5M HCl, and gold(III) adsorption capacities in the solutions including copper(II) and zinc(II) ions were obtained as 0.088 and 0.151 meq Au(III)/g for UF and TF resins, respectively. On the other hand, by column method, the dynamic adsorption capacities were calculated as 0.109 meq Au(III)/g with TF, 0.023 meq Au(III)/g with UF, 0.015 meq Cu(II)/g with TF, 0.0057 meq Cu(II)/g with UF, and under 6.1 Â 10 À5 meq Zn(II)/g with TF or UF. TF resin was more effective in the separation and the concentration of gold(III) ions from copper(II) and zinc(II) ions than UF resin. It was seen that sulfur atoms contributed the gold(III) adsorption comparing with oxygen atoms.

Functionalization of Fe₃O₄/SiO₂ with N-(2-Aminoethyl)-3-aminopropyl for Sorption of [AuCl₄]^-

“…The increase of the amount of Au(III) desorbed from Fe3O4/SiO2/ED is due to the existence of ion H + in solution that can stabilize thiourea and prevent the degradation leadings to decrease the consumption of thiourea [22]. Additionally, Cl -ion from HCl has a function as competitor for the Au(III) complexes [23]. As shown in Fig.…”

Synthesis of a novel dithiooxamide–formaldehyde resin and its application to the adsorption and separation of silver ions

“…These powdered resins were used in the all experimental studies. They were characterized by elemental analysis and FTIR [14][15][16]34,37].…”

“…The condensation of the hydroxymethyl compounds can result in dimethylene ether or only methylene bridges. A highly cross-linked resin may be produced using higher formaldehyde:amine mole ratio before the hydroxymethylation [6,7,14,15,[33][34][35][36][37].…”

“…Silver ion shows affinity to N atom and especially S atom in a functional group. Chelating resins containing N and/or S atoms as donor atoms have great attention due to their selectivity towards silver(I) ions [6,7,[13][14][15][16][17].…”

Effect of γ-irradiation on the hydrolytic stability and thermo-oxidative behavior of bio/inorganic modified urea–formaldehyde resins

“…These peaks (ANACH 2 ANA and ACAOACA) show the cross-linking in the resin via N atoms. Moreover, ACAOACA peaks in the both resins show polyether product [67].…”