•Chelating resins were used to study the adsorption of Cu and Au from glycine-cyanide solutions.•Puromet MTS9300 resin is selected due to its high selectivity towards Cu2+ over Cu+ and Au+.•The ...experimental data of Cu2+ fit with both Freundlich and Langmuir isotherms.•The experimental kinetic data of Cu2+ fit with pseudo-second-order model.•Alkaline glycine solutions with salt can effectively desorb Cu from the resin.
A method is presented to remove and recover copper from copper-gold glycinate solutions using an iminodiacetic functionalized resin with subsequent regeneration. The adsorption/desorption approach was evaluated for a glycine leaching process which was shown to be effective for the dissolution of gold and copper from different gold-copper ores and concentrates. In this process, glycine is the lixiviant in the presence of very low cyanide concentration as a synergistic reagent. The copper species in glycine-cyanide process are mainly present as cupric glycinate and a low concentration of cuprous dicyanide and no free cyanide. While cupric glycinate does not load well onto activated carbon, cuprous dicyanide is problematic due to its high carbon affinity and co-loading with gold onto activated carbon, thereby requiring the removal of most of the copper prior to the gold recovery. In this study, the use of ion-exchange resins as one of the possible downstream recovery processes for gold and copper from glycine-cyanide solutions was tested. The isotherms and kinetics of gold and copper (cupric copper (Cu2+)) adsorb onto the chelating resin (Puromet MTS9300) from their alkaline glycinate and cyanide complexes were studied. Results show that the CNT−: CuT molar ratio has significant effects on the adsorption of CuT, due to the change in Cu2+/Cu+ ratio in the solutions, where CN−T is the total cyanide in the system (free cyanide being zero). The results show that the chelating resin is selectively adsorbed cupric (Cu2+) over cuprous (Cu+) ions. The adsorption results were fitted to both the Freundlich and Langmuir isotherm models, while the Langmuir model shows a better correlation. The adsorption kinetic data of Cu2+ is well fitted to the pseudo-second-order model. Alkaline glycine solutions in the presence of NaCl was selected as the main eluent for the resin elution study. The multi-cycle adsorption/desorption tests showed that the resin adsorption and regeneration efficiencies are not significantly changed after five cycles of adsorption/desorption. Microscopic visual analysis by using scanning electron microscopy (SEM) showed that there is no significant change in shape and size of the resins, although more cracks were observed after the 5 cycles of adsorption/desorption.
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•Nickel ion exchange from complexing media was studied at 22 and 80 °C.•Complexation with SO42− and NH3 indirectly enhance nickel uptake.•In acidic solutions at 80 °C, proton masking ...as bisulfate favors nickel exchange.•In (NH4)2SO4-NH3 solution, nickel uptake is high due to low proton concentration.
In real hydrometallurgical systems, ion exchange of metal cations is often accompanied by competing processes, such as complex formation. In this paper, we have analyzed influence of complex formation on nickel uptake in a chelating ion exchanger that contains iminodiacetate groups. Both outer-sphere complexation with sulfate and inner-sphere complexation with ammonia were studied at 22 and 80 °C. In ammoniacal ammonium sulfate matrix, both these complexes are formed and prediction of nickel uptake becomes challenging. According to the results, nickel uptake can be substantially enhanced by complex formation. Under acidic conditions and at 80 °C, proton is complexed by sulfate more effectively than nickel and as a result, the exchange equilibrium favors nickel uptake. High sulfate background concentration further enhances the positive effect. In ammonium sulfate solutions, however, complexation with ammonia is needed to prevent nickel precipitation. The solution is stable near pH 7 and high nickel uptake can be obtained, because competition by H+ is practically absent and Ni2+/NH4+ selectivity is high. Complexation with NH3 thus makes the conditions favorable for Ni uptake rather than affects directly on Ni exchange. All these findings were successfully correlated with a dynamic model including pertinent complexation and dissociation equilibria.
In this research, the removal of boron and arsenic from geothermal water was examined by using novel
-methyl-d-glucamine functionalized gel-like resins (abbreviated as 1JW and 2JW) synthesized by the ...membrane emulsification method. The outcomes were compared with those of commercially available boron selective chelating ion exchange resin (Diaion CRB 05). According to the results obtained with the novel resins, it was possible to reduce both boron and arsenic concentrations in geothermal water by using these novel gel-like chelating resins below their permissible levels for agricultural irrigation (<1 mg B/L) and drinking water (<0.01 mg As/L) by using the batch method. The optimum resin concentration required for almost complete boron removal (more than 95%) with the two chelating resins was determined to be 2 g/L. The novel gel-like chelating resins 1JW and 2JW achieved 94% of arsenic removal by using the resin concentration of 8 g/L, while the required resin concentration was 32 g/L for 94% of arsenic removal using commercially available Diaion CRB05 resin. In addition, the column performance characteristics of the novel chelating resins for the separation of boron were studied, and the results were compared to those obtained with Diaion CRB05. According to the column data obtained, the total resin capacities of the Diaion CRB05, 1JW, and 2JW resins were calculated as 6.29, 5.08, and 4.64 mg B/mL-resin, respectively.
► Reports improved procedure for production of HEIDA monolithic silica columns. ► New column exhibits improved capacity and efficiency for metal ions. ► Column offers unique selectivity for alkaline ...earth and transition metal cations. ► Results demonstrate multiple ways to manipulate separation selectivity. ► Speciation calculations explain observed retention trends with complexing eluents.
A commercially available porous silica monolithic column (Onyx Monolithic Si, 100mm×4.6mm I.D.) was ‘in-column’ covalently functionalised with 2-hydroxyethyliminodiacetic acid (HEIDA) groups, and applied to the simultaneous and rapid separation of alkaline earth and transition metal ions, using high-performance chelation ion chromatography (HPCIC). With a 0.3mM dipicolinic acid (DPA) containing eluent, the baseline separation of various common transition and heavy metal ions and the four alkaline earth metal ions could be achieved in under 14min with a flow rate of just 0.8mL/min. Detection was achieved using spectrophotometric detection at 540nm after post-column reaction (PCR) with 4-(2-pyridylazo)-resorcinol (PAR). Significant effects from variation of eluent nature, concentration and temperature upon selectivity and retention were demonstrated with the new monolithic silica chelating phase. Under optimised conditions (0.165M LiNO3 eluent, pH 2.5), peak efficiencies of 54,000, 60,000 and 64,000N/m, for Zn2+, Mn2+ and Cd2+, respectively, were recorded, far exceeding that previously reported for IDA based chelation ion exchange columns.
The chelating ion exchange resin - Dowex M 4195 was used in palladium(II) complexes adsorption from the acidic solutions. This study discusses the sorption kinetics, and more specifically the ...interparticle diffusion behavior of palladium(II) onto Dowex M 4195. The adsorption studies were used to determine the amount of palladium(II) complexes uptake (resin loading), the distribution coefficients, and the recovery efficiency of Pd(II) complexes. The influence of the agitation speed, the beads size (mean radius of swollen particles), the palladium concentrations, as well as acid concentrations (ionic strength of solutions), the macrocomponent addition (sodium chloride), and the phases contact time was also discussed. Moreover, the effect of temperature was taken into account during the determination of the isotherms. The experimental data obtained at 100 µg/cm
3
Pd(II) initial concentration were applied to the kinetic models, and the sorption parameters as well as the normal standard deviation were calculated. Moreover, the Langmuir, Freundlich, and Tempkin-Pyzhev isotherm models were applied and the isotherms parameters were calculated.
Chromium may exist in environmental waters as Cr(III) and Cr(IV), the latter being the toxic and carcinogenic form. Since atomic absorption spectrometry (AAS) and inductively coupled plasma atomic ...emission spectrometry can only yield information on total Cr concentration, a polymer resin bearing O,O-donor chelating groups such as the maleic acid-functionalized XAD–(CO)CH=CH–COOH resin was synthesized to selectively retain Cr(III) at pH 4.0–5.5. The dynamic breakthrough capacity of the resin for Cr(III) at pH 5.0 was 7.52mgg−1, and the preconcentration factor extended to 250–300. Chromium(III) in the presence of 250-fold Cr(VI)—which was not retained—could be effectively preconcentrated on the NH4+-form of the resin and determined by AAS or diphenylcarbazide (DPC) spectrophotometry. When Cr(VI) was reduced to Cr(III) with Na2SO3 solution brought to pH 1 by the addition of 1M H2SO4, and preconcentrated on the resin, total Cr could be determined. The developed method was validated with a blended coal sample CRM-1632. Since the adsorption behavior as a function of pH of possible interferent metal ions, e.g. Ni(II), Co(II), Cu(II), Cd(II), Zn(II), Pb(II) and Fe(III), was similar to that of Cr(III), selective elution of Cr(III) from the resin was realized using a mixture of 1wt.% H2O2+1M NH3. The eluate containing Cr as chromate could be directly analyzed by diphenyl carbazide spectrophotometry without any adverse effect from the common interferents of this method, i.e. Fe(III), Cu(II) Hg(II), VO3−, MoO42− and WO42−. Various synthetic waste solutions typical of electroplating bath effluents containing Cr, Cu, Ni, Zn, Na, Ca, cyanide (and chemical oxidation demand (COD), achieved by glucose addition) were subjected to pretreatment procedures such as hypochlorite oxidation (of cyanide) and catalytic oxidation (of COD) with peroxodisulfate. Chromium determination gave satisfactory results. The combined column preconcentration—selective elution—diphenylcarbazide spectrophotometric determination was also successfully applied to the determination of Cr in artificial and real seawater.
The increasing demand for batteries of higher performance characteristics has led to the development of several types of manganese dioxides with optimal battery characteristics. One of these types is ...produced by a partial leach of a manganese ore, to remove the non-manganese metals to a level acceptable for direct use in batteries. The resulting leach solution must, however, undergo treatment to remove the impurity metals. This paper reports the uptake of copper, nickel, cobalt, lead, iron and manganese from manganese chloride leach solution onto the chelating resin Dowex M-4195 in column experiments. The results demonstrate the ability to remove contaminants to an extent satisfying the quality criteria required for the utilization of the manganese chloride solution for preparing manganese chemicals. Column elution tests demonstrated that a two-stage elution scheme whereby sulfuric acid is first used to elute iron, nickel and cobalt from the resin, then a subsequent ammonium hydroxide elution recovers almost all of the copper is superior to a scheme in which ammonium hydroxide is used before sulfuric acid. However, neither of these elution schemes fully eluted all the metals tested in the study.
The single extractions with 15 extractants (agents) (H
2O, KCl, NH
4Cl, NH
4F, CaCl
2, BaCl
2, CuCl
2, LaCl
3, Na
2S
2O
4, (NH
4)
2C
2O
4, Na
4P
2O
7, NTA, EDTA, DTPA, HCl), the optimised BCR ...(Community Bureau of Reference) three-step sequential extraction procedure (SEP) and the solid phase extraction (SPE) by the chelating ion-exchanger Iontosorb Salicyl (cellulose resin containing covalently bound salicylic acid functional groups) were used for the partitioning of Al in very acid soil samples taken from an area influenced by acid mine solutions. The precision, accuracy and repeatibility for all steps of the optimised BCR SEP were checked on the various reference materials (CRM 483 sewage sludge amended soil, CRM BCR 701 freshwater sediment, SRM 2710 and SRM 2711 Montana soils). Also the new indicative values of the optimised BCR SEP fractional Al concentrations were obtained for these reference materials. The aluminium amounts obtained by the used extraction procedures were valuated and discussed from the aspect of the Al concentration in the plants (grass) growing on the same studied soils. The aluminium toxicity indexes (ATI) calculated for the studied soils, the BaCl
2 and acetic acid soil extracts and the grass stems and roots were used for the assessment of the Al toxicity to the plants. The ATI value was defined as the ratio of the nutrient cations (Ca, Mg, K, Na) concentration sum to the Al concentration. The flame atomic absorption spectrometry (LOQ
=
0.2
mg
l
−1) and the inductively coupled plasma optical emission spectrometry (LOQ
=
0.03
mg
l
−1) were used for the aluminium quantification.
An off-line extraction chromatographic technique has been developed using Amberlite XAD-16 (AXAD-16)-
N,
N-dihexylcarbamoylmethyl phosphonic acid, as the stationary phase for the extraction of ...uranium, thorium and lanthanum from nuclear spent fuels as well as from geological and natural water resources. The chemical modifications of the polymeric matrix were monitored using FT-IR spectroscopy, CHNPS elemental analysis and also by thermo gravimetric analysis for water regain measurements. Various physio-chemical parameters influencing the quantitative metal ion extraction by the resin phase were optimized by both static and dynamic methods. The developed resin matrix showed good distribution ratio values under wide concentrations of acidity and pH conditions. Moreover, the sequential separation of analytes is also possible at sample pH 6.5. Also, the polymeric matrix showed superior metal sorption capacities and rapid metal exchange kinetics with a high sample flow rate value of 26
cm
3
min
−1 for all the three analytes. Thus, reducing the time of analyte extraction from large number of samples anticipated in nuclear waste management programs. The quantitative metal ion recovery of >99.8% was effected with 0.5
M (NH
4)
2CO
3 solution. The method was highly sensitive with lower limits of detections to be 10, 20 and 15
ng
cm
−3 for U(VI), Th(IV) and La(III), respectively, with a better pre-concentration values of 333 for U(VI) and Th(IV) and 400 for La(III), respectively paving way for its applicability in pre-concentrating trace analytes from large sample volumes. The analytical data were within 4.2% R.S.D. reflecting the reproducibility and reliability of the developed method.
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