Recovery Of Cu Research Articles

Biological extraction of Cu and Ni from printed circuit boards via redoxolysis with concomitant material characterization

Among the different types of secondary post-consumption wastes, E-wastes or waste electrical and electronic equipment represent the fastest growing and most problematic waste stream with printed circuit boards (PCBs) constituting its major ingredient. Results from the extraction of Cu and Ni from PCBs using biogenic Fe2(SO4)3 obtained from the original isolate Acidithiobacillus ferrooxidans 61 (KM819692) are presented. At. ferrooxidans 61 was grown at a temperature of 30 °C in a modified 9 K medium supplemented with ferrous iron. Two-stage bioleaching was carried out at 600 rpm and 40 °C. Experiments were performed at 10% of pulp density (PD) with 48-h duration (each stage of 24 h), under pH 1 and 20 g/L Fe3+. Under these conditions, overall recovery of Cu and Ni of 95% and 87% respectively was achieved. The obtained results indicate that non-ferrous metals in PCBs may be efficiently leached within two-stage bioleaching coupling bio-oxidation to subsequent redoxolysis. Scanning electron microscope (SEM) images acquisition and elemental mapping were performed to assess the liberation degree of essential phases after size-reduction steps and their implication on bioleaching efficiency.

Selective electrochemical recoveries of Cu and Mn from end-of-life Li-ion batteries

Lithium-ion batteries (LIBs) are a tremendous achievement in the current energy storage landscape. However, there is an increasing demand for their implementation due to a variety of applications, such as mobile devices and a growing market of electric vehicles. Hence, the recycling of end-of-life batteries is one of the ways to satisfy the need for manufacturing new ones; however, this is challenging due to the lack of sustainable and efficient methods on a large scale. Electrochemical methods are widely used in the production of metals and alloys, therefore constituting a promising way for the recovery of critical metals present in cathode materials in LIBs. In this work, cathode materials have been collected from used LIBs from different sources and leached altogether with sulphuric acid and hydrogen peroxide. The resulting solution was treated electrochemically by applying a constant potential of -0.5 V for 20 h, which promoted the selective separation of copper and manganese at the cathode and anode sides, respectively. Complete and selective recoveries of Cu and Mn were proved by ICP-OES methods, while the purity of the obtained products was assessed by XRD, XPS and SEM-EDS analysis. This investigation presents a great potential for the implementation of an electrochemical treatment to recover valuable metals in pure and ready to reuse form from spent LIBs, which can be easily scaled-up as an alternative to current non-green recovery processes.

Enrichment and separation behaviors of impurities from stripped copper wire with super-gravity fields

Supergravity technology is an efficient method to remove trace impurities and recycle valuable components from secondary sources. This study investigated the enrichment and separation behaviors of impurities from simulated Cu alloys that based on the typical impurity compositions (such as Pb, Fe, Sn, Al, and inclusions) of waste stripped copper wire using supergravity technology. After supergravity enrichment, nonmetallic inclusions and Fe impurity were concentrated in the top of the sample, and the enrichment degree positively correlated with the gravity coefficient. The low-melting-point impurities in Cu alloys were separated by supergravity. Improving the gravity coefficient and temperature benefited the removal of Pb and Sn but had negative influence on the recovery of Cu. Ultimately, the removal rates of Fe, Sn, and Pb were 79.1%, 39.8%, and 74.4%, respectively, and the recovery of Cu was 91.2% under the optimal conditions. Based on these results, supergravity technology is feasible for purification of Cu alloy and achieves good application. It has provided theoretical foundation for recycling of high purity copper and also pointed out a green and efficient way for recycling waste stripped copper wire that can improve resource utilization and prevent environmental damage.

Copper removal and recovery from electroplating effluent with wide pH ranges through hybrid capacitive deionization using CuSe electrode

In modern industry, selective extraction and recovery of Cu from strongly acidic electroplating effluent are crucial to reduce carbon emissions, alleviate resource scarcity, and mitigate water pollution, yielding considerable economic and environmental benefits. This study proposed a high-efficiency CuSe electrode to selectively remove Cu from electroplating effluent via hybrid capacitive deionization (HCDI). The potential of this electrode was thoroughly evaluated to assess its effectiveness. The CuSe electrode exhibited superior deionization performance in terms of Cu adsorption capacity, selectivity, and applicability in various water matrices. Specifically, under strong acid conditions (1 M H+), the CuSe electrode maintained an optimal adsorption capacity of 357.36 mg g−1 toward Cu2+. In systems containing salt ions, heavy metals, and actual electroplating wastewater, the CuSe electrode achieved a remarkable removal efficiency of up to 90% for Cu2+ with a high distribution coefficient Kd. Notably, the capacitive deionization (CDI) system demonstrated the simultaneous removal of Cu-EDTA. The removal mechanism was further revealed using ex-situ X-ray diffraction and X-ray photoelectron spectroscopy analyses. Overall, this study presents a practical approach that extends the capabilities of CDI platforms for effectively removing and recovering Cu from acidic electroplating effluent.

Photo-Induced Construction and Recovery of Cu+ Sites in Metal-Organic Frameworks.

The adjustment of the valence state of metal ions is crucial for various applications because peculiar activity originates from metal ions with specific valence. Cu+ can interact with molecules possessing unsaturated bonds like CO via π-complexation, while Cu2+ doesn't have such ability. Meanwhile, Cu+ sites are easily oxidized to Cu2+ , leading to the loss of activity. Despite great efforts, the development of a facile method to construct and recover Cu+ sites remains a pronounced challenge. Here, for the first time a facile photo-induced strategy is reported to fabricate Cu+ sites in metal-organic frameworks (MOFs) and recover Cu+ after oxidation. The Cu2+ precursor was loaded on NH2 -MIL-125, a typical visible-light responsive Ti-based MOF. Visible light irradiation triggers the formation of Ti3+ from Ti4+ in framework, which reduces the supported Cu2+ in the absence of any additional reducing agent, thus simplifying the process for Cu+ generation significantly. Due to π-complexation interaction, the presence of Cu+ results in remarkably enhanced CO capture capacity (1.16mmolg-1 ) compared to NH2 -MIL-125 (0.49mmolg-1 ). More importantly, Cu+ can be recovered conveniently via re-irradiation when it is oxidized to Cu2+ , and the oxidation-recovery process is reversible.

Copper recovery from printed circuit boards leaching solution with bioelectricity generation using microbial fuel cell

Recovery of valuable metals via leaching printed circuit boards (PCBs) has gained moment recently. This work studied the Microbial fuel cell (MFC) performances for recovery of Cu from a Cu2+ solution by examining key operating parameters. A dual-chamber MFC with 6cm × 6cm × 7cm dimensions was constructed. Both anode and cathode electrodes were made of a carbon cloth sheet. The anodic and cathodic chambers were separated by a Nafion membrane. The highest Cu recovery efficiency was 99.7% after 240h batch mode operation, yielding 102 mW/m2 MFC power density output using 1g/L Cu2+ solution as the catholyte (initial pH 3) and an anolyte containing 1g/L sodium acetate inoculated with a sludge from a wastewater treatment plant's anaerobic pond, with 2cm distance between the electrodes made of polyacrylonitrile polymer. The highest open circuit voltage, current density (based on cross-section cathode area) and power density with an external load of 1 kΩ was 555mV, 347mA/m2 and 193 mW/m2, respectively. Additionally, recovery of Cu in the leachate of PCBs using sulfuric acid leaching after 48h was performed and the highest Cu recovery was 50% in 48h.

Statistical Optimization of Bioleaching for Simultaneous Recovery of Cu, Sn, Pb, and Zn from Computer-Printed Circuit Boards

Electronic garbage is one of the fastest-growing waste streams. Its disposal and appropriate management are a worldwide concern. Printed circuit boards (PCBs) are critical components in contemporary electronic gadgets that contain toxic elements. Bioprocessing of PCBs for metal recovery employing microbial methods has evolved as a green solution in metallurgical operations. Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were used in this study to leach metals from powdered waste PCBs. The RSM is used for optimizing the leaching conditions. The optimal conditions obtained were a bacterial activation period of 28 days, a pulp density of 23 g/L, and a temperature of 31°C. A confirmatory experiment under these optimal circumstances yielded recovery rates of Cu2+, Sn2+, Pb2+, and Zn2+ of 95.62%, 96.27%, 95.6%, and 98.25%, respectively.

Recovery of Metals from Printed Circuit Boards by Gold-REC 1 Hydrometallurgical Process

The paper describes a small full-scale plant based on the Gold-REC 1 process, designed and patented by the University of L’Aquila; the hydrometallurgical process allows the treatment of printed circuit boards (PCBs). The first step is a mechanical treatment to reduce the size of the scraps below 2 mm. The extraction of base metals occurs in a first reactor by a sulfuric acid/hydrogen peroxide solution. After filtration, the solid is leached again with thiourea and ferric sulfate in a sulfuric acid solution to extract gold and silver. This second solution is sent to an electrolytic cell where gold is recovered as metal powder. The resulting solution undergoes a second electrowinning, where silver is deposited on the cathode. The first pregnant solution undergoes recovery of Cu and Sn. A simulation was developed using lab-scale trial results. The 350 tons PCBs/year, running in a batch operating mode, produces around 43.8 kg/year of gold, 85.8 kg/year of silver, 42.4 tons/year of copper, and 7.2 tons/year of tin oxide. The results show the profitability of the process: the net present value is EUR 10.7 M, with an internal rate of return of 150% and a discounted payback time of 2 years.

Membrane distillation and ion exchange combined process for mining wastewater treatment, water reuse, and byproducts recovery

In this paper, we propose the combination of direct contact membrane distillation (DCMD) and ion exchange (IX) as an alternative for (i) generating reuse water and (ii) recovering byproducts from the DCMD concentrate by IX, from gold mining wastewater. The DCMD showed a steady flux (5.49 L/m2.h), ions rejection >99.7%, and a permeate recovery rate of 33.9%. The batch equilibrium results showed that the Amberlyst A26 had a strong affinity for H2SO4 (2897.9 mg/g). Conversely, Amberlite IRC747 and Dowex M4195 showed affinity towards Cu (83.4 and 103.1 mg/g), Ni (26.3 and 89.9 mg/g), and Co (6.5 and 24.4 mg/g). Batch kinetics showed that the rate-limiting step was intraparticle diffusion. Batch recovery of H2SO4 (1265 mg/L) from Amberlyst A26 could be achieved with H2O. Although the recovery of Cu (198.6 mg/L, 91.5%), Ni (62.4 mg/L, 30%), and Co (20.1 mg/L, 41.3%) from the Amberlite IRC747 could be achieved H2SO4 (1 mol/L), carryover of impurities was found. On the other hand, the recovery from the Dowex M4195 with NH4OH 4 mol/L was higher and carryover was lower. The fixed-bed tests showed that the ions breakthrough followed the same order as in the batch and they reached the breakpoint faster at higher feed velocity (8 BV/h compared to 4 BV/h). Elution from the Amberlyst A26 fixed bed achieved 7497.4 mg/L of H2SO4 with only 4.1% of carryover from other ions. The Dowex M4195 elution can achieve high selectivity when increasing the eluting agents' strength (H2SO4 0.1 and 1 mol/L, followed by NH4OH 4 mol/L) are used. By that, separated fractions of Cu, Ni, and Co could be recovered by each agent.

Efficient Recovery of Cu from Wasted CPU Sockets by Slurry Electrolysis

In order to maximize the reuse of used electronic component resources, while reducing environmental pollution, Cu metal was recycled from wasted CPU sockets by the reformative slurry electrolysis method. However, the influences on the regulation of the Cu recovery rate and purity from waste CPU slots, by slurry electrolysis, has not been systematically elucidated in previous studies. In this work, the effects of H2SO4 concentration, slurry density, NH4Cl concentration, current density, and reaction time, on the recovery rate and purity of Cu in slurry electrolysis, were researched by systematic experimental methods. The results showed that the recycled metal elements were mainly present as powders from the cathode, rather than in the electrolyte. Moreover, the metallic elements in the cathode powder consisted of mostly Cu and small amounts of Sn and Ni. The recovery rate and purity of Cu were up to 96.19% and 93.72%, respectively, with the optimum conditions being: an H2SO4 concentration of 2 mol/L, slurry density of 30 g/L, NH4Cl concentration of 90 g/L, current density of 80 mA/cm2, and reaction time of 7 h. Compared with previous studies, the Cu recovered in this experiment was present in the cathode powder, which was more convenient for the subsequent processing. Meanwhile, the recovery rate of Cu was effectively improved. This is an important guideline for the subsequent application of slurry electrolysis for Cu recovery.

Targeted Decomplexation of Metal Complexes for Efficient Metal Recovery by Ozone/Percarbonate

Traditional methods cannot efficiently recover Cu from Cu(II)-EDTA wastewater and encounter the formation of secondary contaminants. In this study, an ozone/percarbonate (O3/SPC) process was proposed to efficiently decomplex Cu(II)-EDTA and simultaneously recover Cu. The results demonstrate that the O3/SPC process achieves 100% recovery of Cu with the corresponding kobs value of 0.103 min-1 compared with the typical •OH-based O3/H2O2 process (81.2%, 0.042 min-1). The carbonate radical anion (CO3•-) is generated from the O3/SPC process and carries out the targeted attack of amino groups of Cu(II)-EDTA for decarboxylation and deamination processes, resulting in successive cleavage of Cu-O and Cu-N bonds. In comparison, the •OH-based O3/H2O2 process is predominantly responsible for the breakage of Cu-O bonds via decarboxylation and formic acid removal. Moreover, the released Cu(II) can be transformed into stable copper precipitates by employing an endogenous precipitant (CO32-), accompanied by toxic-free byproducts in the O3/SPC process. More importantly, the O3/SPC process exhibits excellent metal recovery in the treatment of real copper electroplating wastewater and other metal-EDTA complexes. This study provides a promising technology and opens a new avenue for the efficient decomplexation of metal-organic complexes with simultaneous recovery of valuable metal resources.

A sustainable route for the recovery of metals from waste printed circuit boards using methanesulfonic acid

The rapid increase in electronic waste (e-waste) generation and its unsustainable management pose a threat to the environment and human well-being. However, various valuable metals are present in e-waste, which makes it a potential secondary source to recover metals. Therefore, in the present study, efforts were made to recover valuable metals (Cu, Zn, and Ni) from waste printed circuit boards (WPCB) of computers using methanesulfonic acid (MSA). MSA is contemplated as a biodegradable green solvent and has a high solubility for various metals. The effect of various process parameters (MSA concentration, H2O2 concentration, stirring speed, liquid to solid ratio, time, and temperature) was investigated on metal extraction to optimize the process. At the optimized process conditions, 100% extraction of Cu and Zn was achieved, while Ni extraction was around 90%. The kinetic study for metal extraction was performed using a shrinking core model and findings showed that MSA-aided metal extraction is a diffusion-controlled process. Activation energies were found to be 9.35, 10.89, and 18.86 kJ/mol for Cu, Zn, and Ni extraction, respectively. Furthermore, the individual recovery of Cu and Zn was achieved using the combination of cementation and electrowinning, which resulted in 99.9% purity of Cu and Zn. The current study proposes a sustainable solution for the selective recovery of Cu and Zn from WPCB.

Removal of Copper Ions from Wastewater: A Review

Copper pollution of the world's water resources is becoming increasingly serious and poses a serious threat to human health and aquatic ecosystems. With reported copper concentrations in wastewater ranging from approximately 2.5 mg/L to 10,000 mg/L, a summary of remediation techniques for different contamination scenarios is essential. Therefore, it is important to develop low-cost, feasible, and sustainable wastewater removal technologies. Various methods for the removal of heavy metals from wastewater have been extensively studied in recent years. This paper reviews the current methods used to treat Cu(II)-containing wastewater and evaluates these technologies and their health effects. These technologies include membrane separation, ion exchange, chemical precipitation, electrochemistry, adsorption, and biotechnology. Thus, in this paper, we review the efforts and technological advances made so far in the pursuit of more efficient removal and recovery of Cu(II) from industrial wastewater and compare the advantages and disadvantages of each technology in terms of research prospects, technical bottlenecks, and application scenarios. Meanwhile, this study points out that achieving low health risk effluent through technology coupling is the focus of future research.

A novel pH-responsive flocculant for efficient separation and recovery of Cu and Mo from secondary resources via selective flocculation-flotation

A novel pH-responsive flocculant, P(AM-DEA-DPL) (PADD), was first used for efficient separation and recovery of Cu and Mo from secondary resources via selective flocculation-flotation. The selective flocculation behavior, flocculation-flotation and deflocculation of fine molybdenite, chalcopyrite and quartz were researched by single and artificial mixed ore. Moreover, fourier transform infrared (FTIR) spectroscopy, zeta potential, contact angle and fluorescence microscope were utilized to reveal the flocculation and deflocculation mechanism. The results showed that PADD had an excellent selective flocculation of fine molybdenite and chalcopyrite particles in the presence of sodium hexametaphosphate (SHMP), which originated from the bridging molecular chains, electrostatic adsorption and hydrophobic interaction among PADD and the fine hydrophobic particles. Moreover, the floated flocs obtained from the artificial mixed ore of fine molybdenite, chalcopyrite and quartz could be well dissociated to small size particles when the slurry pH was adjusted to 6.0, resulting from the enhanced deprotonation effect and electronegativity of PADD. It would facilitate the further separation of molybdenite and chalcopyrite from the mixed concentrate via flotation. Therefore, PADD hold a broad application prospect with the efficiently recovering and further separating molybdenite and chalcopyrite from secondary resources containing Cu and Mo.

Modelización de un biorreactor discontinuo para lixiviar residuos eléctricos y electrónicos en Guayaquil, Ecuador

The use of electrical and electronic equipment (EEE) has increased considerably worldwide, generating large amounts of waste electrical and electronic equipment (WEEE) of which only 17% is treated. The processing and extraction of metals from printed circuit boards (PCBs) of WEEE is done by a combination of physical and chemical methods, which become highly polluting. Therefore, it is necessary to formulate new eco-friendly strategies to prevent the impact of environmental pollution. The present research proposes to design a Batch bioreactor for the recovery of Cu from WEEE. For this purpose, equations of the modeling of a Batch bioreactor were coupled with real parameters and values taken from the city of Guayaquil and then designed using these values in the AutoCAD design software. A bioreactor was obtained with an optimal agitation considering 8 flat blades for mixing, also the appropriate material is stainless steel, and the optimum working temperature is 28°C. Applying these parameters, a Cu recovery of 96% is obtained in the city of Guayaquil.

Investigation of pyrolysis for the recovery of metallic values from ball grid arrays.

The massive generation of electronic waste has led to a significant interest in sustainable metal recovery and recycling. Ball grid arrays, mounted on printed circuit boards, are identified as a potentially valuable source of metals (Cu, Ni, Au, Ag, Pb, and Sn). In this study, pyrolysis is found as a promising treatment for the degradation of the epoxy resin of ball grid arrays. As a consequence, the liberation of metallic values and glass fibers is attained. The thermal analysis revealed that the major degradation occurs in the temperature range of 300-650°C, with overall activation energy estimated as ~ 243kJ/mol. The concentration of CO gas reaches a maximum value at a comparatively lower residence time with an increase in pyrolysis temperature. The metal enrichment was significantly influenced by the variation in pyrolysis temperatures with an optimal condition chosen as 600°C. The metallic fractions (Cu, Ni, Ag, and Au) were separated from the glass fibers by water-based density separation and enriched in the sink product by three-fold. The recovery of Cu, Ni, Ag, and Au is achieved at 97%, 88%, 95%, and 96%, respectively. The metal fraction can be either used as a feedstock for the Cu smelting process or can be subjected to selective hydrometallurgical treatment. The glass fiber fraction comprises of Si, Al, and Ca oxides with potential application in laminate fabrication. High-quality gaseous products can be reutilized as fuel for other metallurgical processes. It can be concluded that 100g of BGA yielded Cu ~ 23.7g, Ni ~ 0.57g, Ag ~ 23.4mg, and Au ~ 73mg after pyrolysis and density separation, which is equivalent to 1.35kg, of primary Cu ore, 0.042kg Ni ore, 4.68kg Ag ore, and 14.6kg Au ore.

Exploring the effect of pulp aeration and lime-aid grinding on pyrrhotite-rich type copper sulfide ore flotation separation

The traditional high alkaline process (HAP) always encounters challenges in handling pyrrhotite-rich type copper sulfide ore, especially the slow copper flotation rate and the unsatisfactory separation efficiency. In this study, HAP was optimized via pulp aeration and lime-aid grinding, and their beneficial effect was studied systematically. Mineralogical study revealed that the lost Cu in tailings was coarse-grained chalcopyrite with sufficient liberation, confirming traditional HAP was not suitable for the processing of this type ore. Batch flotation tests revealed that the flotation rate and the upper limit of Cu recovery of traditional HAP were very poor, but pulp aeration and lime-aid grinding accelerated chalcopyrite flotation significantly and further increased the upper limit of Cu recovery from 74.6% to 90.0%. Industrial tests further confirmed that the optimized process was suitable for this pyrrhotite-rich type copper sulfide ore in Dongguashan Dressing Plant, and the recovery of Cu increased from 79.8% to 87.7%, significantly. The optimized process not only break through the technical bottlenecks of traditional HAP but bring an additional profit of 207 million yuan per year approximately. Therefore, pulp aeration and lime-aid grinding were expected for widespread application in the beneficiation of pyrrhotite-rich copper mines.

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.

Transformation of oil scum as magnetic char for effective recovery of Cu and Ni from EDTA-bearing wastewater

Blackish ropy scum was collected from the scum vessel of the floatation tank from the petrochemical wastewater treatment plant.

Anoxic iron electrocoagulation automatically modulates dissolved oxygen and pH for fast reductive decomplexation and precipitation of Cu(II)-EDTA: The critical role of dissolved Fe(II).

Fe-based replacement and precipitation are promising methods for removal of copper ethylenediaminetetraacetic acid (Cu(II)-EDTA) but are limited by the necessity of controlling pH and dissolved oxygen. The details of the decomplexation mechanism also remain unclear. The present work investigated an anoxic iron electrocoagulation process capable of automatically modulating anoxic conditions and solution pH during exposure to air and thus promoting the rapid and thorough decomplexation of Cu(II)-EDTA. Dissolved Fe (II), rather than Fe(II)-bearing minerals, was found to be primarily responsible for the reduction of Cu(II)-EDTA to Cu(I)-EDTA and for the subsequent replacement reaction to generate free Cu(I) ions within the initial pH range of 2-7. The Cu(I) was primarily precipitated as Cu2O on the surface of green rust and magnetite as the pH was increased. The aeration of these Fe-containing precipitates released free Cu(I) ions instead of chelated Cu into solution, allowing for recycling of the Cu. This release of Cu(I) was likely induced by the pH decrease during aeration. This study provides important insights regarding the reductive decomplexation of chelated Cu(II) and the recovery of Cu via anoxic iron electrocoagulation, which is a promising green approach to recycling Cu from wastewater.