Selective Extraction Of Cu Research Articles

The Development of Innovated Complex Process for Treatment of Old Flotation Tailings of Copper-Zinc Sulfide Ore.

The possibility of selective Cu and Zn leaching from the sample of old pyrite tailings, which is one of the most widespread types of solid waste forming during non-ferrous metal production, using sulfuric acid solutions and water was studied. It was shown that water leaching provided selective extraction of Cu and Zn and comparatively low iron ion extraction. At the same time, acid leaching provided the obtainment of pregnant solutions with high ferric ion concentration, which can be used for oxidative leaching of substandard copper concentrates. Water and acid leaching also provided increased Au recovery by cyanidation. The results suggest that acid leaching can be an effective approach for processing old flotation tailings, which allows the extraction of base metals from these wastes and treating flotation tailings for subsequent cyanidation. Effective flotation treatment methods should also provide environmental load reduction, which is caused by the long-term storage of metal-bearing wastes.

Selective Extraction of Cu (II) Using Novel C=O–NOH-Contained Compound-Dodecyl Phenyl Ethyl Hydroxamic Acid and Its Extraction Mechanism

ABSTRACT Herein, a novel C=O–NOH-contained compound was synthesized and used in the extraction and recovery of copper from sulfate solution. Dodecyl phenyl ethyl hydroxamic acid (DPEHA) exhibited high selectivity to Cu(II) over the competing ions, and the separation factors (β) obtained were β Cu/Zn = 227.370, β Cu/Co = 199.094, β Cu/Ni = 188.889, respectively. The separation effect was stronger than that of 2-hydroxy-5-nonyl acetophenone oxime. Meanwhile, extraction capacity of 0.10 g Cu(II) per gram DPEHA was reached, and the extracted Cu(II) can be stripped effectively. The investigation of extraction mechanism revealed that O atoms in C=O and O-H groups of DPEHA operate as active sites, which could powerfully chelate with Cu(II) by forming stable five-membered rings. The high copper extraction efficiency and selectivity associated with a simple synthesis of DPEHA make it to serve as the potential selective Cu(II) extractant, which also provide a novel insight for the research and development of economical Cu(II) extractants.

Development of ion-imprinted polymers for the selective extraction of Cu(II) ions in environmental waters

Several ion-imprinted polymers (IIPs) were synthesized via bulk polymerization with Cu(II) as template ion, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as crosslinking agent, and azobisisobutyronitrile as initiator in acetonitrile or methanol as porogen solvent. Non-imprinted polymers (NIPs) were similarly synthesized but without Cu(II). After grounding and sieving, the template ions were removed from IIPs particles through several cycles of elimination in 3 M HCl. All NIPs were equally subjected to this acid treatment with the exception of one NIP, called unwashed NIP. The resulting IIP/NIP particles were packed in solid phase extraction (SPE) cartridges for characterization. The SPE protocol was designed by optimizing a washing step following the sample percolation to eliminate potential interfering ions prior to the elution of Cu(II), all fractions analyzed by inductively coupled plasma mass spectrometry. The best IIP showed a high specificity (recovery of Cu(II) vs. interfering ions) and a good selectivity (retention on IIP vs. NIP). Its adsorption capacity was determined to be 63 μg g−1. Then, a volume of 50 mL was percolated with 30 mg of IIP, thus giving rise to an enrichment factor of 24. Finally, applications to real samples (mineral and sea waters) were successfully performed. In addition, Brunauer-Emmett-Teller analyses showed that the surface area of the washed NIP was almost double that of the unwashed one (140.70 vs. 74.49 m2 g−1), demonstrating for the first time that the post-treatment of a NIP after its synthesis may have a significant impact on its porous structure, and thus need to be more precisely detailed by authors in the future papers.

Selective Extraction of Cu(II) from the Hydrochloric Acid Leaching Solution of Spent Lithium-Ion Batteries by a Mixture of Aliquat 336 and LIX 63

The smelting reduction of spent LIBs produces metallic alloys containing Co, Cu, Fe, Mn, and Ni. These metallic alloys can be completely dissolved by 2 M HCl solution containing H2O2 as an oxidizing agent. Extraction of the leaching solution with D2EHPA results in a Fe(III) free raffinate. In this work, solvent extraction experiments were performed with a mixture of Aliquat 336 and LIX 63 to separate Cu(II) from the Fe(III) free raffinate. This mixture showed selectivity for Cu(II) over Co(II), Mn(II), Ni(II), and Si(IV). The mixture of 0.3 M Aliquat 336 and 0.2 M LIX 63 had the highest synergistic coefficient for the extraction of Cu(II) from the solution. The Cu(II) in the loaded mixture was easily stripped by weak sulfuric acid solution, which facilitates the recovery of copper sulfate from the stripping solution. McCabe-Thiele diagrams for the extraction of Cu(II) by the mixture and for the stripping with sulfuric acid solution were constructed. Three stages of counter-current extraction and stripping experiments verified that only Cu(II) was completely extracted, and the purity of Cu(II) in the stripping solution was higher than 99.9%. Considering the selectivity and easy stripping of Cu(II) from the loaded organic, this mixture can be employed in real operation for the recovery of valuable metals from the leaching solutions of spent LIBs.

The synthesis and use of new amic acid extractants for the selective extraction of Cu(II),Ni(II) and Co(II) from other base metal ions in acidic medium

ABSTRACT We investigate the separation of Co2+ and Ni2+ from base metal ions Co2+, Ni2+, Mn2+, and Li+ ions using solvent extraction in chloroform medium. We also looked at the extraction within a larger pool of metal ions, Mn2+, Ni2+, Co2+, Cu2+, Zn2+, Cd2+, and Li+. Four new ligands were synthesized via a two-step bimolecular nucleophilic substitution and were characterized by conventional means. The ligands were subjected to solvent extraction of Co2+, competitive extraction using metal ions Co2+, Mn2+, Ni2+, and Li+, selectivity tests, loading tests, pH-extraction isotherms, time-dependence, and back extraction. Ligand L4 was the best compared to the other ligands in single and competitive extraction. When considering the pool of metal ions, the percentage extraction of Cu2+ increased as the concentration of ligand L4 was increased. Furthermore, the extraction of Ni2+ and Cu2+ increases with increase of pH as expected. The selectivity changed toward Ni2+ in most of the ligands when the concentration of Cu2+ ion was reduced. Cu2+ metal ions could be 80% back-extracted using 1 mol dm−3 nitric acid during a single stripping. The new extractants extracted Ni2+ preferentially with a high selectivity over Mn2+ and Co2+ in the presence of these three metal ions. The synthesized ligands could perhaps be used in the future for the separation of Ni2+ from a solution containing Mn2+ and Co2+.

Selective electromembrane extraction and sensitive colorimetric detection of copper(II)

Abstract In this study, an extremely effective electromembrane extraction (EME) method was developed for the selective extraction of Cu(II) followed by Red-Green-Blue (RGB) detection. The effective parameters optimized for the extraction efficiency of EME include applied voltage, extraction time, supported liquid membrane (SLM) composition, pH of acceptor/donor phases, and stirring rate. Under optimized conditions, Cu(II) was extracted from a 3 mL aqueous donor phase to 8 µL of 100 mM HCl acceptor solution through 1-octanol SLM using an applied voltage of 50 V for 15 min. The proposed method provides a working range of 0.1–0.75 µg·mL−1 with 0.03 µg·mL−1 limit for detection. Finally, the developed technique was applied to different environmental water samples for monitoring environmental pollution. Obtained relative recoveries were within the range of 93–106%. The relative standard deviation (RSD) and enhancement factor (EF) were found to be ≤4.8% and 100 respectively. We hope that this method can be introduced for quantitative determination of Cu(II) as a fast, simple, portable, inexpensive, effective, and precise procedure.

Selective extraction of Cu+ and Cu2+ ions from mushroom and lichen samples prior to analysis by micro-volume UV-Vis spectrophotometry: Application of a novel poly (SMIm)-Tris-Fe3O4 nanocomposite

In this study, a novel poly (SMIm)-Tris-Fe3O4 nanocomposite was prepared for selective extraction of Cu+ and Cu2+ ions by ultrasound assisted-cloud point extraction (UA-CPE). The nanocomposite was characterized by analysis of ATR-FT-IR, 1H NMR and XRD. After optimization of the extraction conditions, the copper ions were independently detected against sample blank at 347 nm by micro-volume UV–vis spectrophotometer. Under the optimal conditions, good linear relationship was obtained in the ranges of 0.3−150 and 10−350 μg L−1 for each ion at pH 7.0 and pH 5.0, respectively, with a better regression coefficient than 0.992. The method detection limits, accuracy and precision were 0.095 and 3.03 μg L−1, 91.5−96.0 % and 93.0−98.5 %, and 2.5–4.5 and 3.8–7.1 % (n:5, 25 and 100 μg L−1) for Cu+ and Cu2+ ions, respectively. A preconcentration of 70-fold was obtained from 35-mL of sample. After validation, the method was successfully applied to determination of total Cu levels in lichen and mushroom samples after pre-reduction at pH 7.0, and the recoveries in the range of 90−96 % were obtained by two calibration approaches after spiking with 10 μg L−1. The results were also statistically compared with those obtained by FAAS analysis to ensure accuracy and precision.

Transmembrane transport of copper(i) by imidazole-functionalised calix[4]arenes.

Here we present the first synthetic transmembrane transporters for Cu+. Calix[4]arenes with two imidazole groups have a linear coordination motif, which allows selective extraction of Cu+ into chloroform. Transmembrane transport of Cu+ into liposomes was investigated with a newly developed assay and the results open the way to biomedical applications of these Cu+ ionophores.

Selective Extraction of Cu(II) from Sulfuric Acid Leaching Solutions of Spent Lithium Ion Batteries Using Cyanex 301

Spent lithium ion batteries contain cobalt, copper, lithium, manganese and nickel. Recovery of these metals with high purity from spent lithium ion batteries is of importance. A sulfuric acid solution is generally employed for the treatment of spent lithium ion batteries, but it is difficult to separate these metal ions from the leaching solution because the divalent metal ions have similar extraction behaviors. Once Cu(II) is separated from the sulfuric acid leaching solution, the traditional solvent extraction process for the separation of Co(II) and Ni(II) can be applied to the raffinate. Therefore, selective extraction of Cu(II) was investigated in this work using Cyanex 301. The effect of the concentration of sulfuric acid and Cyanex 301 was investigated. Within the sulfuric acid concentration range (pH 5-2.0 M) employed in this work, Cu(II) was completely extracted by Cyanex 301, while the extraction percentage of other metal ions decreased to negligible when the sulfuric acid concentration increased to 2.0 M. The addition of TBP to Cyanex 301 depressed the extraction of other metal ions except Cu(II) at an initial pH of 3, facilitating the selective extraction of Cu(II). The McCabe-Thiele extraction diagram indicates that most of the Cu(II) was extracted by two count-current extraction at an A/O ratio of 2. The Cu(II) loaded in Cyanex 301 was completely stripped by using 5% aqua regia. Key words: spent lithium ion batteries, sulfuric acid, Cyanex 301, copper(II), extraction

Extraction of Copper and Zinc from Waste Printed Circuit Boards

The recovery of valuable metals from waste printed circuit boards (WPCBs) is crucial in order to harness their economic resources, and prevents potential environmental contamination. However, selective extraction of Cu and Zn, and the co-extraction of other metals as impurities at ambient temperature using selected lixiviants such as HCl, H2SO4, HNO3, trifluoromethanesulfonic acid (TFMS), NaOH, and mixtures of NaCl and CuCl2 was studied. It is shown that the extraction efficiencies of all the metals increased with increases in lixiviant concentrations. High selectivity of Cu and Zn toward Fe were achieved in dilute H2SO4, HNO3, TFMS, and 0.5 M NaCl + 0.1 M CuCl2, and low dissolution of Pb (<5%) was observed in all H2SO4 lixiviants. Almost 100% Zn extraction using NaOH lixiviants without trace of other metals was achieved. Therefore, 0.5 M NaCl + 0.5 M CuCl2, 1.0 M HNO3, 0.5 M H2SO4, and 1.0 M TFMS showed high extraction selectivity toward Cu and Zn with low chemical consumption, and produced pregnant leach solution rich in Cu and Zn, as well as residue containing Fe, Ni, and other metals.

Combined application of EDDS and EDTA for removal of potentially toxic elements under multiple soil washing schemes

Chelant-enhanced soil washing, such as EDTA (ethylenediaminetetraacetic acid) and biodegradable EDDS ([S,S]-ethylene-diamine-disuccinic acid), has been widely studied, however, EDTA is persistent under natural conditions while EDDS has a low efficiency for Pb extraction. Therefore, we investigated the efficacy of mixed chelants (EDDS and EDTA mixture at 1:1 M ratio) for the removal of Cu, Zn, and Pb from a field-contaminated soil using various washing schemes (multi-pulse, step-gradient chelant, and continuous washing schemes). Speciation modelling of the target metals, mineral elements, and EDDS/EDTA was performed, while the leachability and bioaccessibility of residual metals in the treated soils were also assessed. Our results suggested that the combined use of EDDS and EDTA reached equivalent extraction efficiency of the target metals as EDTA, i.e., 50% reduction in the dosage of EDTA was made possible. This was accomplished by selective extraction of Cu by EDDS and Pb by EDTA, which was supported by the results of speciation calculation. Multi-pulse washing scheme with intermittent water rinsing steps removed entrapped metal-chelant complexes and free chelants, therefore reducing the leachability and bioaccessibility of residual metals in the treated soils. Step-gradient chelant washing with the maximum dosage of chelants in the first washing step only achieved marginal improvement but undesirably promoted Pb bioaccessibility. Continuous washing for 24 h enhanced metal extraction but promoted mineral dissolution, together with a large amount of uncomplexed chelants and increase in Cu leachability. Thus the combined use of EDDS and EDTA in multi-pulse washing is recommended for further studies.

Improving selective separation of Cu(II) from acidic polymetallic media with 2-ethylhexyl 4-pyridinecarboxylate ester: Extraction behaviors, coordination structure and microscopic mechanism

In this work, the extraction selectivity on Cu(II) against other impurity metal ions is greatly improved with 2-ethylhexyl 4-pyridinecarboxylate ester (LII) as a synergist where dinonylnaphthalene sulfonic acid (HDNNS) was used as an extractant. To illuminate the synergistic extraction mechanism, a model complex of Cu(II) with nahpthalene-2-sulfonic acid (HNS) and n-hexyl 4-pyridinecarboxylate ester (LI) was synthesized and characterized by single crystal X-ray diffraction, elemental analysis, thermo-gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and electrospray ionization mass spectrometry (ESI-MS), respectively. The crystal structure analysis indicates that the molecular structure of the Cu(II) model complex is determined as [Cu(NS)2(LI)2(H2O)4], where Cu(II) is directly coordinated with two deprotonated HNS, two monodentate LI and two water molecules to form a twisted octahedral configuration. Furthermore, in order to provide parallels to actual solvent extraction, the extracted Cu(II) complex in the non-polar organic phase was also prepared and studied using FT-IR and ESI-MS. Compared with the spectra of both the Cu(II) model complex and the extracted Cu(II) complex, it could be inferred that the extracted Cu(II) complex probably has an identical coordination configuration with the Cu(II) model complex, and the inner coordination sphere of Cu(II) might be occupied with N atoms from pyridine ring in two LII molecules, O atoms from two water molecules and O atoms of two deprotonated HDNNS molecules, respectively. The microscopic mechanism on the selective extraction of Cu(II) was proposed.

Tripodal polyamines: Adjustable receptors for cation extraction

ABSTRACTExtraction experiments of a series of tris(2-aminoethyl)amine-based ligands with different aromatic substituents act as efficient extractants for transition metals. Octanol-water distribution measurements, determined stability constants of Ag(I) complexes and Zn(II) extraction studies with different counterions point to the extraction efficiency in dependence of the ligand lipophilicity and the specific structure of the ligand. Competitive extraction experiments showed a selective extraction of Cu(II) from a mixture of Co(II), Ni(II), Cu(II), Zn(II), and Cd(II). Additional hydroxyl groups in (tris(2-hydroxybenzylaminoethyl)amine lead to a loss of this selectivity with extraction yields of 46%, 86% and 97% for Co(II), Ni(II) and Cd(II) ions.

Recovery of copper and recycling of acid from the leach liquor of discarded Printed Circuit Boards (PCBs)

Abstract Present work is focused on the recovery of metal and recycling of acid from the leach liquor of discarded Printed Circuit Boards (PCBs) using solvent extraction technique. The waste PCBs are segregated and processed for leaching under the optimized condition developed by our group at CSIR-NML. Further, the systematic basic studies were carried out to recover nitric acid (HNO3) and copper (Cu) from the leach liquor of PCBs using tri-butyl phosphate (TBP) and 2-hydroxy-5-nonylacetophenone oxime (LIX 84IC), respectively. The leach liquor mainly contains Cu (22.97 g/L) and nitric acid (6.3 mol/L). Various process parameters viz. effect of pH, extractant concentration, time, phase ratio, loading capacity, etc. were studied and optimized. Complete extraction of HNO3 was achieved using TBP in three stages at phase ratio (O/A) 3/1 in mixing time of 15 min. The acid free leach liquor obtained was further used for selective extraction of Cu using LIX 84IC. Mc-Cabe Thiele plot indicates ∼99.99% Cu can be extracted in two stages using 30% LIX 84IC at an equilibrium pH 2, O/A ratio 1/1 in contact time of 15 min. Complete stripping of Cu from loaded organic was achieved with 10% sulfuric acid (H2SO4) in 5 contacts at a phase ratio (O/A) of 1/1. From the pure copper solution metal or salt could be produced by evaporation, precipitation, electrowinning, crystallization, etc.

Surface ion-imprinted amino-functionalized cellulosic cotton fibers for selective extraction of Cu(II) ions

Surface ion-imprinted amino-functionalized cellulosic fibers (Cu-ABZ) were manufactured for efficient selective adsorption of Cu2+ ions. The chemical modification steps had been characterized utilizing elemental analysis; Fourier transforms infrared (FTIR) along with wide angle X-ray diffraction (XRD) spectroscopy. Also, the morphological structure of the ion-imprinted and the non-imprinted (NI-ABZ) fibers were visualized and compared with that of the native cotton fibers using scanning electron microscope (SEM). In addition, the coordination mode by which the Cu2+ ions bonded to the active sites were examined by both FTIR and X-ray photo electron spectra (XPS). Both Cu-ABZ and NI-ABZ were implemented in batch experiments for optimizing the conditions by which the Cu2+ ions can be selectively removal from aqueous medium and pH 5 was the optimum for the metal ion extraction. Moreover, the kinetics and isotherm studies revealed that the adsorption data fitted with pseudo-second-order kinetic and Langmuir models with estimated maximum adsorption capacity 93.6mg/g. Also, the reusability studies indicated that the prepared ion-imprinted adsorbent maintains more than 95% of its original activity after fifth generation cycle.

A Process for Advanced Recycling of Water Originating from Mining Operations, with Metal Recovery

Water associated with mines and mineral pro- cessing, as well as other industrial processes, often contains significant levels of potentially recoverable metals. For example, mineralized water associated with a mining complex in the southern Urals contains high levels of non- ferrous metals (up to 1.1 g/L of Cu and up to 1.8 g/L of Zn). A process has been developed to treat such wastewater as a hydro-mineral resource. Selective extraction of Cu and Zn was incorporated into a proposed water treatment op- eration by combining techniques such as galvanocoagula- tion, sorption, and hydrolytic precipitation.

A novel 4-(2-pyridylazo) resorcinol functionalised magnetic nanosorbent for selective extraction of Cu(II) and Pb(II) ions from food and water samples

This paper describes a novel sorbent based on 4-(2-pyridylazo) resorcinol functionalised magnetic nanoparticles and its application for the extraction and pre-concentration of trace amounts of Cu(II) and Pb(II) ions. The nanosorbent was characterised by Fourier transform infrared spectroscopy, X-ray powder diffraction, thermal analysis, elemental analysis and scanning electron microscopy. The effects of various parameters such as pH, sorption time, sorbent dosage, elution time, volume and concentration of eluent were investigated. Following the sorption and elution of analytes, Cu(II) and Pb(II) ions were quantified by flame atomic absorption spectrometry. The limits of detection were 0.07 and 0.7 μg l−1 for Cu(II) and Pb(II), respectively. The relative standard deviations of the method were less than 7%. The sorption capacity of this new sorbent were 92 and 78 mg g−1 for Cu(II) and Pb(II), respectively. Finally this nanosorbent was applied to the rapid extraction of trace quantities of Cu(II) and Pb(II) ions in different real samples and satisfactory results were obtained.

Preparation of a core–shell magnetic ion-imprinted polymer via a sol–gel process for selective extraction of Cu(ii) from herbal medicines

A novel magnetic surface ion-imprinted polymer (c-MMWCNTs-SiO2-IIP) was synthesized for the first time using magnetic CNTs/Fe3O4 composites (c-MMWCNTs) as the core, 3-ammonium propyltriethoxysilane (APTES) as the functional monomer, tetraethylorthosilicate (TEOS) as the cross-linker and Cu(II) as the template. c-MMWCNTs-SiO2-IIP was evaluated for selective extraction of Cu(II) from herbal medicines via a magnetic solid phase extraction (M-SPE) procedure. One factor affecting the separation and preconcentration of the target heavy metal was pH. Under the optimized experimental conditions, the adsorption kinetics and adsorption capacity of c-MMWCNTs-SiO2-IIP toward Cu(II) were estimated. The results indicated that the adsorption mechanism corresponds to a pseudo-second order adsorption process, with a correlation coefficient (R(2)) of 0.985 and a maximum adsorption capacity of 42.2 mg g(-1). The relative selectivity factor (β) values of Cu(II)/Zn(II) and Cu(II)/Pb(II) were 38.5 and 34.5, respectively. c-MMWCNTs-SiO2-IIP, combined with flame atomic absorption spectrometry, was successfully applied in the extraction and detection of Cu(II) in herbal medicine, with high recoveries ranging from 95.6% to 108.4%.

Synthesis, characterization and application of a novel ion-imprinted polymer for selective solid phase extraction of copper(II) ions from high salt matrices prior to its determination by FAAS

A new Cu(II)-imprinted sorbent has been prepared by using 5-methyl-2-thiozylmethacrylamide (MTMAAm). The monomer of Cu(II)–MTMAAm complex was synthesized and copolymerized in the presence of ethyleneglycol dimethacrylate cross-linker via bulk polymerization method. The resulting Cu(II)-imprinted polymer was characterized by FT-IR spectroscopy and scanning electron microscopy (SEM). Copper ions were removed from the polymer with 1.0molL−1 HNO3 and determined by flame atomic absorption spectrometry (FAAS). The imprinted polymer showed higher selectivity for Cu(II) in comparison to the non-imprinted polymer. Relative selectivity coefficients (k′) for Cu(II)/Zn(II), Cu(II)/Ni(II) and Cu(II)/Co(II) were 9.1, 14.8 and 26.6, respectively. The imprinted polymer was examined as a column packing material for solid phase extraction of Cu(II) from various matrices. The effects of solution pH, acid eluents and interfering ions were investigated. The poylmer possesses selective extraction of Cu(II) within pH range from 5.0 to 6.5. The relative standard deviation and limit of detection (3s) of the method were evaluated as 1.4% and 0.9µgL−1, respectively. The accuracy of the method was verified by analysis of two certified reference materials (CWW-TM-D and SRM 3280) and then applied to the determination of Cu in seawater, lake water and tap water samples, and hemodialysis concentrates and multivitamin/multielement supplements.

Oxidative decolorization of methylene blue by leached sea-nodule residues generated by the reduction-roasting ammoniacal leaching process

The leached residue, generated after selective extraction of Cu, Ni and Co by reductive-roasting ammoniacal leaching of sea nodules, was characterized by various physicochemical methods. The finely divided residue, containing mainly manganese carbonate/silicates and manganese(III,IV) (hydr)oxides along with iron oxides, showed a lower surface area (66.3 m2 g−1) than that of the parent sea nodule (130 m2 g−1). The catalytic efficiency of water-washed sea nodule residue (WSNR) was evaluated taking oxidative decolorization of methylene blue (MB) as the test reaction. The extent of decolorization was decreased with increase in pH but increased in the presence of H2O2 or NaCl. Decolorization of MB occurred in two consecutive steps; the rate constant of the first step was ∼ 10 times higher than that of the second step. The formation of a surface precursor complex between WSNR and MB at a rate-limiting step, followed by electron transfer from MB to the active metal centre of WSNR and release of product(s), was proposed as the decolorization process.