Advanced utilization of copper in waste printed circuit boards: Synthesis of nano-copper assisted by physical enrichment

Zhu, Xiangnan; Nie, Chun-chen; Ni, Yang; Zhang, Tao; Li, Biao; Wang, Dezhang; Qu, Shi-juan; Qiao, Fa-ming; Lyu, Xianjun; Qiu, Jun; Li, Lin; Ren, Yangguang; Wu, Peng

doi:10.1016/j.jhazmat.2020.123294

Cited by 36 publications

(8 citation statements)

References 37 publications

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“…61 The XRD pattern in Figure S4c shows peaks at diffraction angles of 43.05, 50.19, and 73.91°, corresponding to the (111), (200), and (220) planes of the copper phase in the face-centered cubic system (JCPDF#99-0034), which were consistent with the XPS analysis. 62 Although CuO/C was deactivated in the reactions of the model species, the higher phenolic monomer yields indicated that CuO/C exerted just the right catalytic activity during the RCF of natural wood sawdust.…”

Section: ■ Introductionmentioning

confidence: 97%

Metal–Organic-Framework-Derived Copper Catalysts for the Hydrogenolysis of Lignin into Monomeric Phenols

Wang

Xiao

et al. 2022

ACS Catal.

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Reductive catalytic fractionation (RCF) of lignocellulosic biomass has emerged as a leading biorefinery strategy. Herein, we present a copper-based catalyst (CuO/C) derived from a metal–organic backbone (HKUST-1) with enhanced catalytic performance for RCF of woody sawdust, which affords high yields of propyl and propanol end-chain monomeric phenols (15.5 wt % in softwoods and 46.7 wt % in hardwoods) via the C–O bond scission. A series of conifer β-O-4 models and their deuterated analogues revealed that the synergistic action of CuO/C and hydrogen could effectively cleave aryl ether linkages. It was deduced that lignin alcoholysis led to partial α-OH etherification of the β-O-4′ units, which promoted the C–O bond breakage of Cα-OMe and Cβ-O, thus giving propanol phenolic compounds through the hydrogenation of coniferyl alcohol over the CuO/C catalyst. When both α- and γ-OH of β-O-4′ motifs were meoxylated, the para-propyl phenolics were obtained through the scission of C–O linkages (Cα-OMe and Cβ-O), followed by the Cγ-OMe cleavage of propenyl ethers and hydrogenation of propenyl phenols. We envision that this work may pave the way for the development of non-noble catalysts with high reactivity and selectively for lignin valorization.

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Section: ■ Introductionmentioning

confidence: 97%

Metal–Organic-Framework-Derived Copper Catalysts for the Hydrogenolysis of Lignin into Monomeric Phenols

Wang

Xiao

et al. 2022

ACS Catal.

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“…Even recently, a number of pretreatments and leaching processes for waste PCBs recycling have been proposed, such as the following examples. The pretreatment processes such as soaking in NaOH solution [7] and microwave pyrolysis [8] and mineral processing processes [9] such as flotation [10] were investigated to enhance the dissolution efficiency of valuable metals from PCBs. Leaching processes of PCBs have been examined using hydrogen peroxide (H 2 O 2 ) [11][12][13][14], ammonia solution [10,[14][15][16], HNO 3 [16][17][18], halogen [16,17,19,20], glycine [12,13], and ionic liquid [21].…”

Section: Introductionmentioning

confidence: 99%

“…The pretreatment processes such as soaking in NaOH solution [7] and microwave pyrolysis [8] and mineral processing processes [9] such as flotation [10] were investigated to enhance the dissolution efficiency of valuable metals from PCBs. Leaching processes of PCBs have been examined using hydrogen peroxide (H 2 O 2 ) [11][12][13][14], ammonia solution [10,[14][15][16], HNO 3 [16][17][18], halogen [16,17,19,20], glycine [12,13], and ionic liquid [21]. Bacterial leaching processes of PCBs have also been reported as environment-benign processes, where Phanerochaete chrysosporium [22], Acidithiobacillus ferrooxidans [23], Leptospirillum ferriphilum or its mixed culture Metals 2021, 11, 1369 2 of 11 with Acidithiobacillus ferrooxidans [24][25][26], and Frankia sp.…”

Section: Introductionmentioning

confidence: 99%

Leaching of Copper from Waste-Printed Circuit Boards (PCBs) in Sulfate Medium Using Cupric Ion and Oxygen

Park

Eom

Yoo

et al. 2021

Metals

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In the present paper, the leaching of copper from printed circuit boards (PCBs) using sulfuric acid with Cu2+ and O2 is proposed. The effects of various process parameters such as agitation speed, temperature, the type and the flow rate of gas, initial Cu2+ concentration, and pulp density were investigated to examine the dissolution behavior of Cu from PCBs in 1 mol/L sulfuric acid. The kinetic studies were performed using the obtained leaching data. The leaching rate of Cu from PCBs was found to be higher on addition of Cu2+ and O2 to the leachant in comparison with the addition of O2 or both Cu2+ and N2 in the leachant. The leaching efficiency of Cu was found to be increased with increasing agitation speed, temperature, O2 flow rate, and initial Cu2+ concentration and decreasing pulp density. The 96% of Cu leaching efficiency was obtained under the following conditions: sulfuric acid concentration, 1 mol/L; temperature, 90 °C; agitation speed, 600 rpm; pulp density, 1%; initial Cu2+ concentration, 10,000 mg/L; and O2 flow rate, 1000 cc/min. The leaching data and analyses indicate that the Cu leaching from PCBs followed the reaction-controlled model satisfactorily and determined that the activation energy was found to be 23.8 kJ/mol. Therefore, these results indicate that the sulfuric acid solution with Cu2+ and O2 as a mild leach medium without strong oxidants such as HNO3, H2O2, and Fe3+ is valid for Cu leaching from PCBs.

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“…10 mL of leaching solution was used, CTAB, glucose was used for the pre-reduction process at 85 °C. Ascorbic acid reducing agent, and copper was placed in a vacuum drying oven for 24 h at 60 °C to avoid oxidation Cu 99.9% (Zhu et al, 2021 ) Potassium persulfate (K 2 S 2 O 8 ) Variation in Temp. leaching 25, 35, 45, and 55 °C, S/L 1/100, constant magnetic stirring (300 rpm), Cooling recrystallization Cu 99.9% (Liu et al, 2019 ) …”

Section: Electronic Waste Management Systemmentioning

confidence: 99%

E-waste recycled materials as efficient catalysts for renewable energy technologies and better environmental sustainability

Seif

Salem

Allam

2023

Environ Dev Sustain

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Waste from electrical and electronic equipment exponentially increased due to the innovation and the ever-increasing demand for electronic products in our life. The quantities of electronic waste (e-waste) produced are expected to reach 44.4 million metric tons over the next five years. Consequently, the global market for electronics recycling is expected to reach $65.8 billion by 2026. However, electronic waste management in developing countries is not appropriately handled, as only 17.4% has been collected and recycled. The inadequate electronic waste treatment causes significant environmental and health issues and a systematic depletion of natural resources in secondary material recycling and extracting valuable materials. Electronic waste contains numerous valuable materials that can be recovered and reused to create renewable energy technologies to overcome the shortage of raw materials and the adverse effects of using non-renewable energy resources. Several approaches were devoted to mitigate the impact of climate change. The cooperate social responsibilities supported integrating informal collection and recycling agencies into a well-structured management program. Moreover, the emission reductions resulting from recycling and proper management systems significantly impact climate change solutions. This emission reduction will create a channel in carbon market mechanisms by trading the CO2 emission reductions. This review provides an up-to-date overview and discussion of the different categories of electronic waste, the recycling methods, and the use of high recycled value-added (HAV) materials from various e-waste components in green renewable energy technologies.

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Advanced utilization of copper in waste printed circuit boards: Synthesis of nano-copper assisted by physical enrichment

Cited by 36 publications

References 37 publications

Metal–Organic-Framework-Derived Copper Catalysts for the Hydrogenolysis of Lignin into Monomeric Phenols

Metal–Organic-Framework-Derived Copper Catalysts for the Hydrogenolysis of Lignin into Monomeric Phenols

Leaching of Copper from Waste-Printed Circuit Boards (PCBs) in Sulfate Medium Using Cupric Ion and Oxygen

E-waste recycled materials as efficient catalysts for renewable energy technologies and better environmental sustainability

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