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Xia D, Lee C, Charpentier NM, Deng Y, Yan Q, Gabriel JP. Drivers and Pathways for the Recovery of Critical Metals from Waste-Printed Circuit Boards. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2309635. [PMID: 38837685 PMCID: PMC11321694 DOI: 10.1002/advs.202309635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 04/15/2024] [Indexed: 06/07/2024]
Abstract
The ever-increasing importance of critical metals (CMs) in modern society underscores their resource security and circularity. Waste-printed circuit boards (WPCBs) are particularly attractive reservoirs of CMs due to their gamut CM embedding and ubiquitous presence. However, the recovery of most CMs is out of reach from current metal-centric recycling industries, resulting in a flood loss of refined CMs. Here, 41 types of such spent CMs are identified. To deliver a higher level of CM sustainability, this work provides an insightful overview of paradigm-shifting pathways for CM recovery from WPCBs that have been developed in recent years. As a crucial starting entropy-decreasing step, various strategies of metal enrichment are compared, and the deployment of artificial intelligence (AI) and hyperspectral sensing is highlighted. Then, tailored metal recycling schemes are presented for the platinum group, rare earth, and refractory metals, with emphasis on greener metallurgical methods contributing to transforming CMs into marketable products. In addition, due to the vital nexus of CMs between the environment and energy sectors, the upcycling of CMs into electro-/photo-chemical catalysts for green fuel synthesis is proposed to extend the recycling chain. Finally, the challenges and outlook on this all-round upgrading of WPCB recycling are outlined.
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Affiliation(s)
- Dong Xia
- SCARCE LaboratoryEnergy Research Institute @ NTUNanyang Technological UniversitySingapore639798Singapore
| | - Carmen Lee
- SCARCE LaboratoryEnergy Research Institute @ NTUNanyang Technological UniversitySingapore639798Singapore
- School of Material Science and EngineeringNanyang Technological UniversitySingapore639798Singapore
| | - Nicolas M. Charpentier
- SCARCE LaboratoryEnergy Research Institute @ NTUNanyang Technological UniversitySingapore639798Singapore
- Université Paris‐SaclayCEACNRSNIMBELICSENGif‐sur‐Yvette91191France
| | - Yuemin Deng
- Université Paris‐SaclayCEACNRSNIMBELICSENGif‐sur‐Yvette91191France
- Ecologic France15 Avenue du CentreGuyancour78280France
| | - Qingyu Yan
- SCARCE LaboratoryEnergy Research Institute @ NTUNanyang Technological UniversitySingapore639798Singapore
- School of Material Science and EngineeringNanyang Technological UniversitySingapore639798Singapore
| | - Jean‐Christophe P. Gabriel
- SCARCE LaboratoryEnergy Research Institute @ NTUNanyang Technological UniversitySingapore639798Singapore
- Université Paris‐SaclayCEACNRSNIMBELICSENGif‐sur‐Yvette91191France
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Koskinen J, Frimodig J, Samulinen M, Tiihonen A, Siljanto J, Haukka M, Väisänen A. Optimization of Selective Hydrometallurgical Tantalum Recovery from E-Waste Using Zeolites. ACS OMEGA 2024; 9:14947-14954. [PMID: 38585115 PMCID: PMC10993384 DOI: 10.1021/acsomega.3c08907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 02/20/2024] [Accepted: 03/08/2024] [Indexed: 04/09/2024]
Abstract
To protect future high-tech metal demand, a selective and efficient recovery method for tantalum from a tantalum-rich e-waste component sample was developed. Ultrasound-assisted digestion of the component sample was optimized, and the highest dissolution rate was achieved using a mixture of 8 mol/L H2SO4 and HF at a temperature of 60 °C. The determined amount of tantalum was as high as 11 000 ± 1000 mg/kg, which results in a high potential for recyclable tantalum. The other major elements of this complex e-waste fraction were silicon, iron, aluminum, and tin. Efficient recovery of tantalum from the leachate was performed using the zeolite material ZSM-5. Extremely high selectivity and a recovery rate of over 98% were obtained. In terms of adsorption efficiency, selectivity, and durability of the material, optimal adsorption was obtained using the diluted sample at 0.5 mol/L of H2SO4. The adsorption capacity of ZSM-5 for tantalum was determined to be 10.5 ± 0.6 mg/g, and tantalum was selectively eluted with 1:4 diluted ethanolamine with a yield of 87.2 ± 1.5%.
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Affiliation(s)
- Jutta Koskinen
- Department
of Chemistry, University of Jyväskylä, P.O. Box 35, Jyväskylä FI-40014, Finland
| | - Janne Frimodig
- Department
of Chemistry, University of Jyväskylä, P.O. Box 35, Jyväskylä FI-40014, Finland
| | | | - Antti Tiihonen
- Department
of Chemistry, University of Jyväskylä, P.O. Box 35, Jyväskylä FI-40014, Finland
| | - Jimi Siljanto
- Department
of Chemistry, University of Jyväskylä, P.O. Box 35, Jyväskylä FI-40014, Finland
| | - Matti Haukka
- Department
of Chemistry, University of Jyväskylä, P.O. Box 35, Jyväskylä FI-40014, Finland
| | - Ari Väisänen
- Department
of Chemistry, University of Jyväskylä, P.O. Box 35, Jyväskylä FI-40014, Finland
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3
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Tan M. Conversion of agricultural biomass into valuable biochar and their competence on soil fertility enrichment. ENVIRONMENTAL RESEARCH 2023; 234:116596. [PMID: 37423358 DOI: 10.1016/j.envres.2023.116596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 07/11/2023]
Abstract
Globally several nations generates a large amount of biomass waste. Thus, this review focuses on the potential for converting plant biomass into nutritionally enriched useful biochar with promising properties. The use of biochar on farmland acts as both a soil fertility enhancer, improving both the physical as well as chemical characteristics of soil. The biochar availability in soil can retain minerals and water as well as considerably enhanced the soil fertility by their optimistic characteristics. Thus, this review also discuss about how biochar enhances the quality of agriculture soil and polluted soil. Since, the biochar derived from the plant residues might contain most valuable nutritional properties, which can enhance the physicochemical properties of soil and that can support the growth of plant along with the increased biomolecule content. Since, the healthy plantation can support the production of nutritionally enriched crop yield. Agriculture biochar amalgamated soil significantly improved soil beneficial microbial diversity. Beneficial microbial activity increased soil fertility and balanced the soil's physicochemical properties significantly. Such balanced soil physicochemical properties significantly enhanced plantation growth, as well as disease resistance and higher yield potential than any other fertiliser supplements for soil fertility and plant growth.
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Affiliation(s)
- Mingjiao Tan
- Yangtze Normal University, Chongqing, 408100, China; Visiting Scholar of Huazhong Agricultural University, Wuhan, 430070, China.
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4
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Separation of waste tantalum capacitors by supercritical methanol: Recovery of high-purity metal tantalum and producing of bisphenol/diphenyl chemicals. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Recovery of Tantalum and Manganese from Epoxy-Coated Solid Electrolyte Tantalum Capacitors through Selective Leaching and Chlorination Processes. MATERIALS 2022; 15:ma15020656. [PMID: 35057373 PMCID: PMC8781639 DOI: 10.3390/ma15020656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/10/2022] [Accepted: 01/14/2022] [Indexed: 01/25/2023]
Abstract
Electronic products are ever growing in popularity, and tantalum capacitors are heavily used in small electronic products. Spent epoxy-coated solid electrolyte tantalum capacitors, containing about 22 wt.% of tantalum and 8 wt.% of manganese, were treated with selective leaching by hydrochloric acid and chlorination after removing the epoxy resin, and the products converted, respectively, to Mn(OH)2 and TaCl5. The effects of acid type, acid concentration, liquid–solid ratio, and reaction time were investigated to dissolve the manganese. The optimal selective leaching conditions were determined as 3 mol/L of HCl, 40 mL/g at 25 °C for 32 min. Next, residues of selective leaching after washing and drying were heated with ferrous chloride to convert to pure TaCl5. Mixing 48 wt.% of chloride and 52 wt.% of residues for a total of 5 g was conducted to complete the chlorination process in the tube furnace at 450 °C for 3 h. A total of 2.35 g of Ta was collected and the recovery of Ta achieved 94%. Finally, Mn(OH)2 and TaCl5 were separated and purified as the products.
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Joo J, Kwon EE, Lee J. Achievements in pyrolysis process in E-waste management sector. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 287:117621. [PMID: 34171724 DOI: 10.1016/j.envpol.2021.117621] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/29/2021] [Accepted: 06/16/2021] [Indexed: 06/13/2023]
Abstract
Many aspects of modern life of our civilization are associated with using electrical and electronic devices (EEE). Ever-increasing demand for high-performance EEE and accelerated technological development make the replacement of EEE become frequent. This leads to the generation of a tremendous amount of electronic waste (E-waste). Challenges of the management of E-waste have recently arisen out of a dearth of proper technologies to treat E-waste. Pyrolysis process can thermochemically treat waste materials that have a complicated nature and inhomogeneity. This article gives a systematic review as an effort to tackle the challenges in the context of achievements in pyrolysis process in E-waste management sector. Pyrolysis mechanism and types of pyrolysis processes and pyrolysis reactors are first discussed. Various pyrolysis technologies applied to the E-waste treatment are then summarized and compared to each other. Points to be considered for further research and pending challenges of E-waste pyrolysis are also discussed. The pyrolysis treatment of E-waste is not yet fully industrialized mostly because of high costs. However, there should be much room for further developing the E-waste pyrolysis; hence, its industrialization and commercialization is just a matter of time.
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Affiliation(s)
- Junghee Joo
- Department of Energy Systems Research, Ajou University, 206 World Cup-ro, Suwon, 16499, Republic of Korea
| | - Eilhann E Kwon
- Department of Environment and Energy, Sejong University, 209 Neungdong-ro, Seou, 05006, Republic of Korea
| | - Jechan Lee
- Department of Energy Systems Research, Ajou University, 206 World Cup-ro, Suwon, 16499, Republic of Korea; Department of Environmental and Safety Engineering, Ajou University, 206 World Cup-ro, Suwon, 16499, Republic of Korea.
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Yousaf B, Liu G, Ubaid Ali M, Abbas Q, Liu Y, Ullah H, Imtiyaz Cheema A. Decisive role of vacuum-assisted carbonization in valorization of lignin-enriched (Juglans regia-shell) biowaste. BIORESOURCE TECHNOLOGY 2021; 323:124541. [PMID: 33370680 DOI: 10.1016/j.biortech.2020.124541] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/06/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Bioenergy is considered a sustainable substitute to fossil-fuel resources and the development of a prudent combination of renewable and innovative conversion technologies are essential for the valorization and effective conversion of biowaste to value-added commodities. Here, a negative pressure-induced carbonization process was proposed for the valorization of lignin-enriched biowaste precursor to bio-oil and environmental materials (biochar) at various temperatures. The high heating values (HHV) of the as-prepared biochars from the lignin enriched precursor under negative pressure (low-medium vacuum) were within 25.9-31.5 MJ/kg, which matched satisfactorily to the commercial charcoal. Whereas, the bio-oils produced from the lignin enriched precursor under vacuum conditions was a blend of complex aromatic and straight-chain hydro-carbons, including aldehyde, ketone, phenol, and furans, exhibiting ability as potential heating-oil with HHV within 21.2-28.2 MJ/kg. Moreover, the biochars produced under vacuum environments at higher temperature showed greater stability (22.5-35.9%) than those produced under N2 atmosphere.
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Affiliation(s)
- Balal Yousaf
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, Xi'an, Shaanxi 710075, China; Environmental Engineering Department, Middle East Technical University, Ankara 06800, Turkey
| | - Guijian Liu
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, Xi'an, Shaanxi 710075, China.
| | - Muhammad Ubaid Ali
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, And State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518000, China
| | - Qumber Abbas
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Yuan Liu
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Habib Ullah
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ayesha Imtiyaz Cheema
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
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Duan Z, Fiquet O, Ablitzer C, Cassayre L, Vergnes H, Floquet P, Joulia X. Application of pyrolysis to remove hydrogen from an organic nuclear waste. JOURNAL OF HAZARDOUS MATERIALS 2021; 401:123367. [PMID: 32653790 DOI: 10.1016/j.jhazmat.2020.123367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/28/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
The work deals with the removal by slow pyrolysis of epoxy resin from samples of spent nuclear fuel embedded in this polymer. Beyond the nuclear field, epoxy resin removal by pyrolysis is a typical issue for the recovery of metals in electronic waste. The main objective is to find the optimal conditions to remove hydrogen in the residual solid waste, in order to avoid hydrogen production by radiolysis during storage and so to prevent any risk of overpressure and explosion. The condensable pyrolysis products (tar-water mixture) and the char were characterised and quantified by elemental analyses, while the permanent gases were quantified by gas chromatography. A data reconciliation method was applied to adjust the values of raw measurements in order to complete the mass balances for both C, H, O and N elements and pyrolysis products. After studying the impact of temperature on the pyrolysis balance, experiments on a pilot furnace were conducted at 450 °C, in the frame of a parametric study of the heating rate, argon gas flow rate, resin mass and plateau time. At fixed temperature, we show that the plateau time is the only significant parameter for minimizing the residual hydrogen content in the char.
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Affiliation(s)
- Zhiya Duan
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France; CEA, DEC, Cadarache, 13108, Saint-Paul-lez-Durance, France
| | - Olivier Fiquet
- CEA, DEC, Cadarache, 13108, Saint-Paul-lez-Durance, France
| | | | - Laurent Cassayre
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France
| | - Hugues Vergnes
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France
| | - Pascal Floquet
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France
| | - Xavier Joulia
- Laboratoire de Génie Chimique, Université de Toulouse, CNRS, INP, UPS, Toulouse, France.
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Foong SY, Chan YH, Cheah WY, Kamaludin NH, Tengku Ibrahim TNB, Sonne C, Peng W, Show PL, Lam SS. Progress in waste valorization using advanced pyrolysis techniques for hydrogen and gaseous fuel production. BIORESOURCE TECHNOLOGY 2021; 320:124299. [PMID: 33129091 DOI: 10.1016/j.biortech.2020.124299] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 06/11/2023]
Abstract
Hydrogen and gaseous fuel derived from wastes have opened up promising alternative pathways for the production of renewable and sustainable fuels to substitute classical fossil energy resources that cause global warming and pollution. Existing review articles focus mostly on gasification, reforming and pyrolysis processes, with limited information on particularly gaseous fuel production via pyrolysis of various waste products. This review provides an overview on the recent advanced pyrolysis technology used in hydrogen and gaseous fuel production. The key parameters to maximize the production of specific compounds were discussed. More studies are needed to optimize the process parameters and improve the understanding of reaction mechanisms and co-relationship between these advanced techniques. These advanced techniques provide novel environmentally sustainable and commercially procedures for waste-based production of hydrogen and gaseous fuels.
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Affiliation(s)
- Shin Ying Foong
- Henan Province Engineering Research Center For Biomass Value-Added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China; Pyrolysis Technology Research Group, Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
| | - Yi Herng Chan
- PETRONAS Research Sdn. Bhd. (PRSB), Lot 3288 & 3289, Off Jalan Ayer Itam, Kawasan Institusi Bangi, 43000 Kajang, Selangor, Malaysia
| | - Wai Yan Cheah
- Department of Environmental Health, Faculty of Health Sciences, MAHSA University, 42610 Jenjarom, Selangor, Malaysia
| | - Noor Haziqah Kamaludin
- Department of Environmental Health, Faculty of Health Sciences, MAHSA University, 42610 Jenjarom, Selangor, Malaysia
| | | | - Christian Sonne
- Aarhus University, Department of Bioscience, Arctic Research Centre (ARC), Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Wanxi Peng
- Henan Province Engineering Research Center For Biomass Value-Added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China
| | - Pau-Loke Show
- Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia
| | - Su Shiung Lam
- Henan Province Engineering Research Center For Biomass Value-Added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China; Pyrolysis Technology Research Group, Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.
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Liu Y, Zhang L, Song Q, Xu Z. Recovery of palladium and silver from waste multilayer ceramic capacitors by eutectic capture process of copper and mechanism analysis. JOURNAL OF HAZARDOUS MATERIALS 2020; 388:122008. [PMID: 31951988 DOI: 10.1016/j.jhazmat.2019.122008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 10/15/2019] [Accepted: 12/30/2019] [Indexed: 06/10/2023]
Abstract
Recycling waste multilayer ceramic capacitors (MLCCs) is significant for environmental protection and resource recovery, which contain rich precious metals including palladium and silver. The existing recycling methods have many shortcomings such as environmental pollution, low recovery efficiency and low purity of precious metals. In view of the special structure of MLCCs and low content of precious metals per unit mass, a novel approach of enrichment for recovering palladium and silver from waste MLCCs by eutectic capture process of copper was proposed, in which process precious metals were separated and enriched for subsequent recovery. The recovery rates of palladium and silver reached 100 % and 87.53 %, respectively under the optimal condition. And the enrichment multiples of palladium and silver were 13.16 and 7.37. The Cu-Pd-Ag alloy was formed in the capture process, of which palladium and copper formed Cu-Pd solid solution, while silver was a separate phase through the analysis of SEM-EDS, XPS and XRD. Besides, the molten residue can be reused to prepare glass-ceramics. Finally, the mechanism was analyzed through thermodynamics, which was divided into two processes: migration of precious metals and alloy formation. This study provides a highly efficient and environmentally friendly method for recycling precious metals from waste MLCCs.
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Affiliation(s)
- Ya Liu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China
| | - Lingen Zhang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China
| | - Qingming Song
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China
| | - Zhenming Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, People's Republic of China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, People's Republic of China.
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11
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Dissolution of manganese (IV) oxide from tantalum capacitor scrap by organic acids. ACTA INNOVATIONS 2019. [DOI: 10.32933/actainnovations.32.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The dissolution of MnO2 from tantalum capacitor scrap using organic acids in various process conditions was studied. The initial materials were of two types: LTC (leaded tantalum capacitors) and SMDTC (surface-mounted device tantalum capacitors). The research materials were prepared by pyrolysis, grinding and sieving and the preparation processes were characterized. Dissolution of MnO2 was carried out with the use of sulfuric acid solutions with the addition of acetic, ascorbic, citric and oxalic organic acids. Results show that the addition of organic acids significantly improves dissolution yields (72-94 vs 90-99 % for H2SO4 and acid mixtures, respectively). In practice, a concentration of organic acid above 1 M results in the complete removal of MnO2.
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Gao R, Xu Z. Pyrolysis and utilization of nonmetal materials in waste printed circuit boards: Debromination pyrolysis, temperature-controlled condensation, and synthesis of oil-based resin. JOURNAL OF HAZARDOUS MATERIALS 2019; 364:1-10. [PMID: 30336331 DOI: 10.1016/j.jhazmat.2018.09.096] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/23/2018] [Accepted: 09/30/2018] [Indexed: 06/08/2023]
Abstract
The rapid replacement of electric and electronic equipment has produced large amount of waste printed circuit boards (WPCBs). At present, physical and mechanical methods are widely used to recover valuable metals from WPCBs. Unfortunately, produced nonmetal materials (NMMs) were typically hazardous waste and were usually disposed by landfill. Considering the characteristics of structure and composition of NMMs, debromination pyrolysis was regarded as the appropriate technique to decompose organics. However, pyrolysis oil and pyrolysis residue were still typically hazardous and difficult to disposal or recycle. Hence, we proposed a novel integrated method to reuse NMMs. The results showed that temperature-controlled condensation method was effective to separate pyrolysis oil. Besides, bromine was removed from organics and formed CaBr2. Pyrolysis oil was used to synthesize oil-based resin. FT-IR, 1H and 13C NMR and TG analysis results indicated that oil-based resin had the same structure and thermostability with commercial resin, which suggested that oil-based rein had economic value. In addition, CaBr2 in residual could be recycled by water leaching and filter residues can be used as ideal reinforcing material for building materials. This study raises a comprehensive method to utilize NMMs and recover value materials effectively, sustainably and environmentally friendly.
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Affiliation(s)
- Ruitong Gao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China
| | - Zhenming Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 20092, PR China.
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