Recovery Of Cu Research Articles

Analysis of Cu, Co, V and Zn in coastal waters of the East China Sea by inductively coupled plasma mass spectrometry (ICP-MS)

In this study, a simple method for the simultaneous determination of trace metals (Cu, V, Co, Zn) in coastal seawater using the Mg(OH)2 coprecipitation inductively coupled plasma mass spectrometry (ICP-MS) was developed. This multi-element method enables the simultaneous extraction of four metals, particularly Co and V. The recoveries of Cu, Co, V and Zn after Mg(OH)2 coprecipitation were 73%, 96%, 94% and 92%, which means that our procedure was well-suited to the determination of these four trace metals. The detection limits were 3.81, 0.18, 6.09 and 1.91 nmol L−1, respectively. Then, applying this method to the simultaneous determination of these four metals in coastal water samples from the East China Sea revealed that the concentrations of Cu, Zn, Co and V were higher in bottom waters compared to water at other depths, and higher concentrations were generally observed at the Yangtze River estuary. Additionally, example vertical profiles of dissolved trace metal concentrations for the East China Sea in spring and autumn are compared. These findings indicate that Zn had the greatest seasonal variation followed by Cu, V and Co. For Zn and Co, the concentrations were higher during spring than during autumn. For Cu and V, the seasonal variation in the concentrations was opposite.

Advanced Metal Contamination Analysis for High Efficiency Solar Cell Manufacturing

In view of the increasing importance of wafer surface purity for the manufacturing of high efficiency cells we present here a sensitive method for the quantitative determination of wafer surface contaminations. Our results show that the detection limits are sufficient for process control in solar cell manufacturing. Particularly, the analysis and recovery of Cu is regarded, which may – besides Fe – play an important role in the degradation of surface and interface quality of high efficiency solar cells.

Bioleaching of valuable metals from spent lithium-ion mobile phone batteries using Aspergillus niger

In this paper, a bio-hydrometallurgical route based on fungal activity of Aspergillus niger was evaluated for the detoxification and recovery of Cu, Li, Mn, Al, Co and Ni metals from spent lithium-ion phone mobile batteries under various conditions (one-step, two-step and spent medium bioleaching). The maximum recovery efficiency of 100% for Cu, 95% for Li, 70% for Mn, 65% for Al, 45% for Co, and 38% for Ni was obtained at a pulp density of 1% in spent medium bioleaching. The HPLC results indicated that citric acid in comparison with other detected organic acids (gluconic, oxalic and malic acid) had an important role in the effectiveness of bioleaching using A. niger. The results of FTIR, XRD and FE-SEM analysis of battery powder before and after bioleaching process confirmed that the fungal activities were quite effective. In addition, bioleaching achieved higher removal efficiency for heavy metals than the chemical leaching. This research demonstrated the great potential of bio-hydrometallurgical route to recover heavy metals from spent lithium-ion mobile phone batteries.

Fluorometric determination of copper(II) using CdTe quantum dots coated with 1-(2-thiazolylazo)-2-naphthol and an ionic liquid

The sulfur-containing reagents dithizone, 2,3-dimercapto-1-propanol, 2-thenoyltrifluoroacetone, 1,3,4-thiadiazole-2,5-dithiol, and 1-(2-thiazolylazo)-2-naphthol (TAN) were first examined with respect to their stabilizing effect on CdTe nanocrystals. The indicator TAN was found to best passivate the surface of CdTe NCs if added during synthesis of the NCs at 100 °C. These NCs (referred to as NC-1) have an emission that peaks at 430 nm, and a quantum yield (QY) of 25 %. If, however, TAN-capped particles are prepared in presence of an ionic liquid at room temperature, the QY of such nanocrystals (referred to as NC-2) is increased by 80 % and the emission peak is shifted to 460 nm. The NC-1 particles bind Ag(I), Pb(II), Hg(II), Fe(III), Cr(III), and Cu(II) in phosphate buffer of pH 6.5 while NC-2 particles bind Cu(II) only. Binding of metal ions is associated with a drop in fluorescence intensity. In case of NC-1, quenching is observed in the 23.3 nM to 23.3 μM Cu(II) concentration range with detection limit of 0.5 nM. In case of NC-2, quenching occurs in the 233 nM to 233 μM Cu(II) concentration range with detection limit of 5.0 nM. The method was applied to the determination of Cu(II) in spiked biosamples, and recoveries of Cu(II) (at a 233 nM level) in BSA and fetal bovine serum using NC-2 are 95 % and 92 %. This is better than the recoveries from the same media with NC-1 (70 % and 32 %). These findings demonstrate that the NC-2 material is superior in terms of selectivity and stability but inferior in terms of detection limit.

Simultaneous degradation of ofloxacin and recovery of Cu(II) by photoelectrocatalysis with highly ordered TiO2 nanotubes

A photoelectrocatalytic system for removal of ofloxacin and Cu2+ complex was developed. In such a photoelectrocatalytic system, highly ordered titanium dioxide nanotubes served as a highly active photoanode for photoelectrocatalytic degradation of ofloxacin; and titanium plate was used as the cathode, on which Cu2+ ions were electrodeposited. Compared with other treatment methods including photocatalysis, electrochemistry and direct photolysis, photoelectrocatalytic technique exhibited the highest removal efficiency for either ofloxacin or Cu2+. To obtain the optimum photoelectrocatalytic operation conditions, some influencing factors such as current, pH and supporting electrolyte concentration were investigated systematically. The mutual influence analysis indicated that the photoelectrocatalytic removal efficiency of ofloxacin was first promoted by Cu2+ but was then suppressed with prolonging the treatment time; whereas the removal of Cu2+ was always promoted by ofloxacin over the whole photoelectrocatalytic treatment process. Furthermore, the photoelectrocatalytic removal of ofloxacin −Cu2+ was studied by differential pulse voltammetry and high-performance liquid chromatography-mass spectrometry. The results indicated that although Cu2+ influenced the removal rate of ofloxacin, it did not change the degradation mechanism of ofloxacin. The formation of an electroactive intermediate product during the photoelectrocatalytic process was clearly observed by voltammetric analysis. Based on intermediate products identified by high-performance liquid chromatography-mass spectrometry, a possible photoelectrocatalytic removal mechanism for ofloxacin −Cu2+ was proposed.

Effect of desliming on the flotation of a complax copper ore from China

The complex copper oxide ore sample was taken from Deerni copper deposit, Qinghai Province of China. Batch flotation tests had been conducted to upgrade the copper concentrate by conventional amyl xanthate reagents under 73% -74 μm of the particle size; however, the unsatisfied results (Cu grade of 18.21% and recovery of 59.25%) were obtained. Also there are a large amount of slimes trapped in the concentrate and high-dosages consumption of reagents, for example, more than 2.5 kg/t sodium sulfide and 1.5 kg/t sodium silicate at only one-staged roughing. Based on the analysis of the sample, most of gangues are clay, feldspar and mica, which may easy to over-grind and deteriorate the flotation process either on reagents consumption or slurry fluidity or viscosity. A hydro-cyclone had been introduced to pre-concentrate the oxide ore by scrubbing the slime before flotation, which can result obviously in reducing the dosages of sodium sulfide from 2.5 Kg/t to 1 Kg/t, and raising the grade of Cu in the concentrate from 18.21% to 26.65% at the expense of about 1% recovery of Cu. In this paper, the effects on the recovery of Cu by the different dosages of flotation reagents with or without de-sliming were studied, with the objective of determining the different effects on the functions of flotation reagents by slime during flotation.

Application of D-optimal design for optimizing copper-molybdenum sulphides flotation

Froth flotation is widely used for concentration of base metal sulphide minerals in complex ores. One of the major challenges faced by flotation of these ores is selection of the type of flotation reagents. In this study, the D-optimal experimental design method was applied to determine the optimum conditions for flotation of copper and molybdenum in the rougher flotation circuit of the Sungun copper concentrator plant. The investigated parameters included types and dosages of collectors and frothers, diesel dosage and feed size distribution. The main effects on copper and molybdenum recoveries and grades were evaluated. Results of optimization showed that the highest possible grade and recovery were obtained for Z11 as a primary collector (20 g/Mg), R407 as a first promoter collector (20 g/Mg), X231 as a second promoter collector (7 g/Mg), A65 (15 g/Mg) and Pine oil as frothers (5 g/Mg), 20 g/Mg of diesel dosage, and d80 of feed size was equal to 80 μm. The analysis of variance showed that the primary promoter collector was the most significant parameter affecting the recovery of Cu, while diesel dosage and d80 were the most significant parameters influencing the Mo recovery.

A novel approach for flotation recovery of copper and molybdenite from a copper-arsenic ore

In recent years, there has been an increasing focus on the utilization of copper-arsenic ore. In this paper, the flotation behavior of arsenic and copper minerals from Peru copper ore was investigated. The results obtained from the flotation tests indicate that the grinding fineness and the lime dosage have significant effects on the flotation of copper and arsenic. With the increase in the lime dosage in the rougher flotation, Cu recovery of rougher concentrates rises slightly, while the recovery of As has a tendency to decline. However, the large amount of lime used leads to a decrease in the Cu and As grade. With an increasing proportion of particles of a particle size less than 0.074 mm in the slurry, the recovery of Cu and As increases correspondingly. The optimum process operating parameters were established as follows: MT-20 as the collector, a grinding size of 60% particles less than 0.074 mm, the lime dosage in the rougher flotation is 2000 g/t with pH at around 9.0, and AH-2 as a highly effective depressant in concentration. With the employment of this technique, a copper concentrate with a Cu grade of 26.55% and recovery of 88.09% was obtained. Meanwhile, the As grade of this concentrate is only 0.35%, and its recovery is 40.67%. It can be seen that a promising recovery technology for Northern Peru copper ore was obtained by this work.

Flotation separation of chalcopyrite from galena by sodium humate and ammonium persulfate

The flotabilities of chalcopyrite and galena with sodium humate (HA) and ammonium persulfate (APS) as the depressant were studied by flotation test, adsorption measurement and infrared spectroscopic analysis. Single mineral flotation test shows that the slurry oxidation environment and the proper oxidation of galena surface are prerequisites for the depression of galena by sodium humate. The closed-circuit flotation test of copper/lead bulk concentrate shows that the grade and recovery of Cu reach 30.47% and 89.16% respectively and those of Pb reach 2.06% and1.58% respectively in copper concentrate, and the grade and recovery of Pb reach 50.34% and 98.42% and those of Cu reach 1.45% and 10.84% respectively in lead concentrate with HA and APS. The selective depression effect of HA and APS is more obvious than that of potassium dichromate. The results of FTIR analysis and adsorption measurements indicate that the adsorption of sodium humate on the fresh surface of galena is negligible, while after oxidation, sodium humate can be chemically adsorbed on the surface of galena. According to the theory of solubility product, the sodium humate can display the oxidation product PbSO4, after then, adsorb on the surface of lead chemically to produce inhibitory effect. Thus, it can be seen that the combination of HA and APS is an efficient non-toxic reagent to achieve cleaning separation copper/lead bulk concentrate by flotation. The combination of HA and APS is an efficient non-toxic reagent to achieve cleaning for copper/lead bulk concentrate by flotation.

Environmental impact and potential utilization of historical Cu-Fe-Co slags.

Historical slags from the past Fe and Cu-Co production were investigated in order to evaluate either their potential for utilization or their long-term environmental risk for unsupervised old smelting areas. Here, we studied ferrous slags produced during the recovery of Fe from siderite-Cu ores in Slovakia and two different types of non-ferrous slags produced during the recovery of Cu and Co from Kupferschiefer ores in Germany. The glassy character, rare occurrence of primary silicate phases, and the lack of secondary phases in Cu slags indicate their stability for a prolonged period of time. Electron microprobe analytical work showed that the metals and metalloids (Cu, Co, Fe, Zn, Pb, As) are largely encased in droplets of matte and metal alloys and remain protected by the glassy matrix with its low weathering rate. Fe and Co slags are composed of high-temperature silicates such as wollastonite, cristobalite, as well as olivine, feldspar, quartz, leucite, pyroxene, and pyroxenoids. The presence of secondary phases attests to a certain degree metal release owing to weathering. Assuming minimal contents of metals in slags after a treatment with dilute H2SO4, slags could be used as pozzolanas for addition to cement.

Micellar mediated selective leaching of manganese nodule in high temperature sulfuric acid medium

The present study evaluates the possibility of selective leaching of manganese from complex, manganese and iron oxy-hydroxide based sea bed nodule utilising micelles in high temperature acid dissolution process. Application of surfactants during acid leaching of manganese nodules are described based on results from leaching studies. The factors that affected the sulfuric acid leaching of the manganese nodules in the presence of various surfactants were investigated. The effect of anionic (SDS-Sodium Dodecyl Sulphate), cationic (CTAB-Cetyl Trimethyl Ammonium Bromide) and nonionic (Triton-X 100) surfactant on the various metals extraction with respect to sulfuric acid concentration, temperature, type of surfactants and surfactant concentration is reported. Among them, CTAB showed highest improvement in the recovery of Cu, Ni, Co, Zn and Mn. Iron, aluminium, and silica were removed effectively through the present approach of high temperature sulfuric acid leaching route assisted by surfactant. Increasing the temperature of the medium has significant impact in the selective leaching of Mn, Cu, Ni and Co. The optimum conditions established for maximum metal extraction are: pulp density 10%, time 2h, temperature 160°C, sulfuric acid 5.0% (v/v) and at critical micellar concentration of CTAB. Under these conditions, recovery of Mn was 99% along with the (˃99%) recovery of Cu, Co, and Ni. The leached residues were analysed and their phase and morphologies were included herein. The present process may find application of separation of manganese from iron and aluminium at high temperature during various hydrometallurgical treatment of manganese based ores.

Determination of copper in industrial water by innovative flow injection flame atomic absorption spectrometry

ABSTRACTAn online flow injection procedure for the preconcentration of copper at µg L−1 levels was developed using a novel chelating resin and flame atomic absorption spectrometry for the analysis of industrial water. Amberlite XAD-2 functionalized with dithizone resin was packed in a minicolumn for flow injection. The pH, sample and eluent flow rates, and eluent concentration were optimized to ensure maximum recovery of Cu(II). The effect of concomittant ions on Cu (II) sorption was also investigated. The limit of detection and enrichment factor for a 180 s preconcentration time were 76 and 0.6 µg L−1, respectively. The resin offered precision of 1.0% for seven successive determinations of 100 µg L−1 Cu(II). The resin was used for more than 300 sorption and desorption cycles without appreciable loss of efficiency. The accuracy of the preconcentration procedure was confirmed by fortified recovery studies in industrial water with NIST certified copper nitrate with recovery exceeding 96%. Validation was performed by the analysis of a standard reference material.

Activated Carbon from Sewage Sludge for Preconcentration of Copper

ABSTRACTSewage sludge was pyrolyzed in an inert atmosphere at 550°C after chemical treatment with ZnCl2 or KOH using an organic precursor to inorganic weight ratio of 1:1. The materials were used as adsorbents for removal of Cu(II) from aqueous solution. The adsorbents were characterized using adsorption/desorption nitrogen isotherms, thermal analysis, scanning electron microscopy, and elemental analysis. The results showed that copper removal was linked to surface pH and compounds present on the surface of the adsorbent. The KOH-treated adsorbent had a smaller surface area (186 m2 g−1) than the ZnCl2-treated adsorbent (192 m2 g−1). However, the KOH-treated adsorbent provided more efficient removal of Cu(II). The performance of the KOH-treated adsorbent may be due to the presence of basic groups on the surface. The Liu isotherm model provided the best description of the equilibrium data: The maximum adsorption capacities at 298 K for KOH-treated, ZnCl2-treated, and untreated sewage sludge were 31.85, 19.79, and 3.513 mg g−1, respectively. The highest desorption was obtained using 1.50 mol L−1 of HNO3 as the eluent. The recoveries of Cu(II) loaded adsorbents were 98.9% for ZnCl2-treated and 95.5% for KOH-treated adsorbents.

Copper(II)-Specific Fluorogenic Task-Specific Ionic Liquids as Selective Fluorescence Probes and Recyclable Extractants.

The designed synthesis of a series of copper(II) specific fluorogenic hydrophobic task-specific ionic liquids (TSILs) from a new naphthalene-based tetradentate ligand is reported. Absorption and fluorescence spectral studies reveal both the ligand and its derivative TSILs show exclusive selectivity towards copper(II) ions. The Stern-Volmer method for calculation of the detection limit for ligand and TSIL1-3 shows values of 0.12, 20, 17, and 15 μM, respectively. Extraction and striping studies by doping these TSILs in [bmim][NTf2] demonstrated that these TSILs are recyclable extractants for the selective recovery of Cu(II) ions from a mixture of 14 relevant metal chloride aqueous solutions in biphasic liquid-liquid extraction with approximately 95% recovery.

Recovery of Cu(II) by chemical reduction using sodium dithionite: effect of pH and ligands.

Wastewaters containing Cu(II) and ligands are ubiquitous in various industrial sectors, and efficacy of copper removal processes, especially precipitation, is greatly compromised by ligands. Chemical reduction, being commonly employed for production of metal nanoparticles, is also effective for metal removal. Adjustment of pH and addition of ligands are important to control the particle size in metallic nanoparticle production. Exploiting the fact that ligands and metals coexist in many wastewaters, chemical reduction was employed to treat ligand-containing wastewater in this study. The experimental result shows that depending on pH, type of ligands, and copper:ligand molar ratio, copper could be removed by either the reduction or precipitation mechanism. Almost complete copper removal could be achieved by the reduction mechanism under optimal condition for solutions containing either EDTA (ethylenediaminetetraacetic acid) or citrate ligands. For solutions containing ammonia, depending on pH and Cu:ammonia molar ratio, copper was removed by both precipitation and reduction mechanisms. At pH of 9.0, formation of nano-sized particles, which readily pass through a 0.45 μm filter used for sample pretreatment before residual copper analysis, results in the lowest copper removal efficiency. Both cuprous oxide and metallic copper are identified in the solids produced, and the possible explanations are provided.

Utilization of Sapindus saponaria (soap nut) bark powder for the removal of Cu(II) ions from aqueous environment

Sapindus saponaria bark powder (SSBP), an agro-waste material was investigated as a biosorbent for the removal and recovery of Cu(II) from aqueous solution. This biosorbent was characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and elemental analysis. The influence of various parameters such as effect of initial pH, contact time, metal ion concentration and sorbent dose on the removal of Cu(II) was investigated using batch process. Langmuir, Freundlich and Dubinin–Radushkevich isotherm models were applied to describe the adsorption isotherms. The Langmuir model fitted the equilibrium data better than the other isotherm models. The maximum adsorption capacity of Cu(II) was calculated from the Langmuir isotherm and found to be 37.09 mg g−1 at pH 5.0. The kinetic studies revealed that the biosorption of Cu(II) onto SSBP followed the pseudo-second-order rate model. Evaluated thermodynamic parameters, ∆G°, ∆H° and ∆S°, showed that the biosorption of Cu(II) onto SSBP was an endothermic process. Desorption studies were carried out with dilute hydrochloric acid for quantitative recovery of the metal ions as well as to regenerate the adsorbent.

Solvent extraction separation of copper and zinc from MSWI fly ash leachates

Fly ash from combustion of municipal solid waste (MSW) contains significant amounts of metals, some of which are valuable and some of which are potentially toxic. This type of ash is most often stabilized and landfilled which means that the metals will be difficult to reclaim at a later stage. In recent years efforts have been made to develop feasible methods to recover selected metals, such as Zn, from MSW fly ash. If this would be possible, a significant amount of valuable metals could be re-inserted in the industrial material loops.This paper describes the development and evaluation of a process for recovery of Cu and Zn from MSW combustion fly ash based on hydrochloric acid leaching followed by two solvent extraction processes, one for each metal. The separation of Cu from the acid leachate was done using an aldoxime extractant, LIX860N-I, in kerosene and a mixture of phosphine oxides, Cyanex 923, also in kerosene, was used for extraction of Zn from the Cu-depleted aqueous phase. The extraction of Cu was selective, but a significant amount of other metals, such as Fe and Pb, were co-extracted together with Zn. It was shown that it is possible to decrease the contamination of Fe by using a suitable concentration of nitric acid solution for stripping or by removing the contaminating metals through cementation.The suggested process was tested for two MSW combustion fly ashes in laboratory scale experiments and gave Cu yields of 69–87% and Zn yields of 75–80% based on the contents in the ash.

Recovery of Cu(II) by chemical reduction using sodium dithionite

Wastewaters containing Cu(II) along with ligands are ubiquitous in various industrial sectors. Efficacy of treatment processes for copper removal, especially precipitation, is greatly debilitated by ligands. Chemical reduction being commonly employed for production of metal nanoparticles has also been used for removing copper. Addition of ammonia was reported to be essential for improving copper reduction efficiency by increasing copper solubility at alkaline pH values. In this study, chemical reduction was employed to treat ligand-containing wastewater, exploiting the fact that ligands and metals are coexisted in many wastewaters. Result shows that copper ions were removed by either reduction or precipitation mechanisms depending on pH, type of ligands, and mixing condition. Complete copper reduction/removal was achieved under optimal condition. The lowest removal efficiency observed at pH 9.0 for ammonia system is due to formation of nano-sized particles, which are readily to pass through 0.45μm filter used for sample pretreatment before copper analysis. Instead of producing metallic copper, cuprous and copper oxide are identified in the samples collected from ammonia system and EDTA system, respectively. Re-oxidation of metallic copper particles by atmospheric oxygen during sample handling or incomplete reduction of Cu(II) ions during reduction process might be the cause. Finally, reduction process was applied to treat real wastewater, achieving complete removal of copper but only 10% of nickel.

Elemental determination of foulings developed in nanofiltration of synthesized liquid low-level radioactive wastes: an LA-ICP-MS study

Herein, we adopted means of LA-ICP-MS to determine the element composition of fouling developed in the end of 24 h filtration of synthesized low-level radioactive liquid. Our experiment results showed that cations possessing identical charges would deposit together, while observed low mass recoveries of Cu, Fe, and Ag ions suggested they have deposited deep in membranes than others. It was therefore speculated that fouling developed might be attributed to the formation of precipitate of high affinity transition metal oxides such as ferric hydroxides and low solubility element such as the hydroxides of Mg and Ca ions.

High Flux Recovery of Copper(II) from Ammoniacal Solution with Stable Sandwich Supported Liquid Membrane

The recovery of Cu(II) from ammoniacal solutions with the sandwich supported liquid membrane was studied by using 4-ethyl-1-phenyl-1,3-octadione as the carrier. The transport behavior of Cu(II), membrane stability and selectivity were investigated. The transport efficiency of Cu(II) in the membrane module is evidently dependent on the feed pH, carrier concentration, phase ratio and temperature, but almost independent of the H2SO4 concentration in receiving phase. The increase of carrier concentration and temperature can simultaneously enhance Cu(II) transport and initial copper flux in the feed phase, while both of them decrease as the phase ratio increases. The initial copper flux can reach 759 mmol m–2 h–1 at 45 °C. A satisfied membrane stability was obtained, and the copper concentration in the receiving phase can reach 3.91 g L–1 via uphill transport after five cycles. The main transport resistance could derive from the diffusion process of the copper complexes through the receiving phase/membrane interface. Moreover, the Cu(II) can be selectively recovered over Ni(II) and Zn(II). The high flux and good membrane stability makes the system promising for recovering metal values from various industrial process effluents.