Selective elution of the gold cyanide complex from anion exchange resin using mixed solvents

Rajasingam, Rueben; Jayasinghe, Nivari S.; Lucien, Frank P.; Tran, Tam

doi:10.1016/j.mineng.2005.09.054

Cited by 20 publications

(8 citation statements)

References 23 publications

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“…As we known, the nonaqueous solvents and mixed solvents have a profound effect on the selectivity of both anion and cation exchange and have been studied for many years. 29 The difference between the counterion exchange in water and organic solvent (water/methanol mixture, methanol and acetone) may be due to the reason that the hydrophobic PFO ion in water rejected the surrounding water molecules and was poorly solvated. So the large hydrophobic ions are usually unstable in water.…”

Section: Resultsmentioning

confidence: 99%

Tunable wettability via counterion exchange of polyelectrolyte brushes grafted on cotton fabric

Jiang

Wang

2012

New J. Chem.

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Poly [2-(methacryloyloxy)ethyltrimethylammonium chloride] (PMETAC) was grafted onto cotton fabric by surface-initiated atom transfer radical polymerization (SI-ATRP). The wettability of the as-prepared cotton fabric surface can reversibly switch between superhydrophobic (1541) and superhydrophilic (o 51) by exchanging the counterions between perfluorooctanoate anion (PFO) and SCN À , respectively. The effect of solvent on the counterion exchange was investigated, and we found that water was a poor solvent for counterion exchange, while other solvent systems, such as water/methanol, methanol and acetone, were good solvents for counterion exchange in this study. Moreover, the effect of the anions on the wettability of the PMETAC films was also studied. The as-prepared cotton fabric with controllable wettability may find application in soft superhydrophobic materials and multifunctional textiles.

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Section: Resultsmentioning

confidence: 99%

Tunable wettability via counterion exchange of polyelectrolyte brushes grafted on cotton fabric

Jiang

Wang

2012

New J. Chem.

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“…However, others have observed that the relatively high concentration of other ions may change the adsorption preference. [60,61] As pH increases from 9 to 13, the concentration of OH − increases while CN − stays the same in the solution. Even though OH − is typically less preferred by anionic resins, the abundant OH − competes with CN − for the active adsorption sites, and as such reduces the resin's CN − removal capacity.…”

Section: Effect Of Phmentioning

confidence: 99%

Removal of aqueous cyanide with strongly basic ion-exchange resin

Simsek

Kobya

Khan

et al. 2015

Environmental Technology

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The removal of cyanide (CN-) from aqueous solutions using a strongly basic ion-exchange resin, Purolite A-250, was investigated. The effects of contact time, initial CN- concentration, pH, temperature, resin dosage, agitation speed, and particle size distribution on the removal of CN- were examined. The adsorption equilibrium data fitted the Langmuir isotherm very well. The maximum CN- adsorption capacity of Purolite A-250 was found to be 44 mg CN- g(-1) resin. More than 90% CN- adsorption was achieved for most CN- solutions (50, 100, and 200 mg CN- L(-1)) with a resin dose of 2 g L(-1). The equilibrium time was ∼20 min, optimum pH was 10.0-10.5, and optimum agitation speed was 150 rpm. An increase in adsorption of CN- with increasing resin dosage was observed. Adsorption of CN- by the resin was marginally affected (maximum 4% variation) within an environmentally relevant temperature range of 20-50 °C. Fixed-bed column (20.5 mm internal diameters) experiments were performed to investigate the effects of resin bed depth and influent flow rate on breakthrough behaviour. Breakthrough occurred in 5 min for 0.60 cm bed depth while it was 340 min for 5.40 cm bed depth. Adsorption capacity was 25.5 mg CN- g(-1) for 5 mL min(-1) flow rate and 3.9 mg CN- g(-1) for 20 mL min(-1) flow rate. The research has established that the resin can be effectively used for CN- removal from aqueous solutions.

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“…For example, Zhang and Dreisinger used composite eluant solutions in the recovery of Au(I) from ammoniacal thiosulfate gold ore leachates using Dowex resins, while Al-Merey et al used potassium peroxodisulfate and acetone–water–nitric acid mixture to elute AuBr 4 – from Dowex 1×4 anion-exchange resin. Rajasingam et al used mixed solvents for the elution of Au(CN) 2 – from Purolite A500, a strong base anion-exchange resin . Resins with selective functional groups can improve significantly their separation efficiency.…”

Section: Introductionmentioning

confidence: 99%

“…For example, Zhang and Dreisinger 9 used composite eluant solutions in the recovery of Au(I) from ammoniacal thiosulfate gold ore leachates using Dowex resins, while Al-Merey et al 10 − from Purolite A500, a strong base anion-exchange resin. 11 Resins with selective functional groups can improve significantly their separation efficiency. For instance, Vernon and Zin 12 reported on the use of a chelating resin containing nsubstituted hydroxylamine functional groups for the selective separation of Au(III) from its nitric acid solutions containing Ag(I), Fe(III), and Cu(II).…”

Section: ■ Introductionmentioning

confidence: 99%

Microfluidic Fabrication of Micropolymer Inclusion Beads for the Recovery of Gold from Electronic Scrap

Zhang

Croft

Cattrall

et al. 2021

ACS Appl. Mater. Interfaces

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A composite material, referred to as micropolymer inclusion beads (μPIBs), was fabricated for the first time using a microfluidic technique and applied successfully for the recovery of Au(III) from simulated digests of electronic scrap. Best results for the extraction of Au(III) were achieved with μPIBs consisting of 55% (m/m) poly(vinyl chloride) as the base polymer, 35% (m/m) Aliquat 336 as the extractant, and 10% (m/m) 1-tetradecanol as a modifier. The size and surface morphology of the μPIBs were examined using optical microscopy and scanning electron microscopy, respectively. A batch of 200 mg μPIBs allowed the complete and selective extraction of Au(III) (2.85 mg) from 50 mL of a simulated digest of electronic scrap containing other metal ions, including 1365 mg Cu(II). The extracted Au(III) was quantitatively stripped from the μPIBs into 50 mL of 0.1 mol L −1 solution of thiourea. No Cu(II) and only sub-microgram levels of Cd(II) and Zn(II) were detected in this solution, thus confirming the suitability of the μPIBs for the efficient recovery of Au(III) from digests of electronic scrap. The microfluidic method used in this study is expected to be applicable for the fabrication of μPIBs for the selective separation of other chemical species by varying the composition of the beads.

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Selective elution of the gold cyanide complex from anion exchange resin using mixed solvents

Cited by 20 publications

References 23 publications

Tunable wettability via counterion exchange of polyelectrolyte brushes grafted on cotton fabric

Tunable wettability via counterion exchange of polyelectrolyte brushes grafted on cotton fabric

Removal of aqueous cyanide with strongly basic ion-exchange resin

Microfluidic Fabrication of Micropolymer Inclusion Beads for the Recovery of Gold from Electronic Scrap

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