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Li XG, Gao Q, Jiang SQ, Nie CC, Zhu XN, Jiao TT. Review on the gentle hydrometallurgical treatment of WPCBs: Sustainable and selective gradient process for multiple valuable metals recovery. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 348:119288. [PMID: 37864943 DOI: 10.1016/j.jenvman.2023.119288] [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: 06/05/2023] [Revised: 09/20/2023] [Accepted: 10/06/2023] [Indexed: 10/23/2023]
Abstract
The metal resource crisis and the inherent need for a low-carbon circular economy have driven the rapid development of e-waste recycling technology. High-value waste printed circuit boards (WPCBs) are an essential component of e-waste. However, WPCBs are considered hazardous to the ecosystem due to the presence of heavy metals and brominated organic polymers. Therefore, achieving the recycling of metals in WPCBs is not only a strategic requirement for building a green ecological civilization but also an essential guarantee for achieving a safe supply of mineral resources. This review systematically analyzes the hydrometallurgical technology of metals in WPCBs in recent years. Firstly, the different unit operations of pretreatment in the hydrometallurgical process, which contain disassembly, crushing, and pre-enrichment, were analyzed. Secondly, environmentally friendly hydrometallurgical leaching systems and high-value product regeneration technologies used in recent years to recover metals from WPCBs were evaluated. The leaching techniques, including cyanidation, halide, thiourea, and thiosulfate for precious metals, and inorganic acid, organic acid, and other leaching methods for base metals such as copper and nickel in WPCBs, were outlined, and the leaching performance and greenness of each leaching system were summarized and analyzed. Eventually, based on the advantages of each leaching system and the differences in chemical properties of metals in WPCBs, an integrated and multi-gradient green process for the recovery of WPCBs was proposed, which provides a sustainable pathway for the recovery of metals in WPCBs. This paper provides a reference for realizing the gradient hydrometallurgical recovery of metals from WPCBs to promote the recycling metal resources.
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Affiliation(s)
- Xi-Guang Li
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Qiang Gao
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Si-Qi Jiang
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Chun-Chen Nie
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Xiang-Nan Zhu
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
| | - Tian-Tian Jiao
- College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
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Zhang X, Tao Y, Tao D, Fangyuan M. Experimental study on the macerals enrichment of low-rank coal by rotary triboelectric separator. PARTICULATE SCIENCE AND TECHNOLOGY 2022. [DOI: 10.1080/02726351.2021.1966146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Xuebin Zhang
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Youjun Tao
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Dongping Tao
- School of Resources and Environmental Engineering, Shandong University of Technology, Zibo, Shandong, China
| | - Ma Fangyuan
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
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3
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Zhang X, Tao Y, Tao D, Ma F, Xian Y. Experimental study on rotary triboelectric separation of low-rank coal macerals with surface modification. PARTICULATE SCIENCE AND TECHNOLOGY 2022. [DOI: 10.1080/02726351.2022.2050860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Xuebin Zhang
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Youjun Tao
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Dongping Tao
- School of Resources and Environmental Engineering, Shandong University of Technology, Zibo, Shandong, China
| | - Fangyuan Ma
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Yushuai Xian
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
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Dai G, Han J, Duan C, Tang L, Peng Y, Chen Y, Jiang H, Zhu Z. Enhanced flotation efficiency of metal from waste printed circuit boards modified by alkaline immersion. WASTE MANAGEMENT (NEW YORK, N.Y.) 2021; 120:795-804. [PMID: 33234472 DOI: 10.1016/j.wasman.2020.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/28/2020] [Accepted: 11/03/2020] [Indexed: 06/11/2023]
Abstract
Efficient recycling of waste printed circuit boards by flotation has become a research focus. In this study, waste printed circuit boards were treated by alkaline immersion to enhance the flotation efficiency. Firstly, the SEM-EDS analysis of the crushed products shown that metal and nonmetal were completely liberated in the -0.25 mm fraction. When the printed circuit boards were modified by alkaline immersion, the recovery of metal increased from 64.34% to 72.35%. Further, the mixture of metal and nonmetal at the edge of nonmetal was discovered by EPMA. This was the cause of metal loss during the flotation process. Secondly, by adjusting the alkaline immersion time and pH value, a good flotation effect was achieved at 40 min alkaline immersion time and the pH = 11. Meanwhile, the XPS analysis of nonmetal found that the intensity of the OH peak was significantly enhanced, while the intensity of the O peak was evidently decreased. The change of the resin molecular structure indicated that the O linked to the benzene ring was broken under the action of alkaline immersion, resulting a free bond was generated on the benzene ring. This made the free OH adsorb to the free bond. This conduct promoted the dispersion of nonmetal in the slurry due to the increased nonmetal surface energy and metal hydrophilicity. Thus, this study provides a new route to improve the flotation efficiency of waste printed circuit boards.
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Affiliation(s)
- Guofu Dai
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
| | - Jun Han
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
| | - Chenlong Duan
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China.
| | - Ligang Tang
- School of Environment Engineering, North China Institute of Science and Technology, Sanhe 065201, China.
| | - Yonghui Peng
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
| | - Youmei Chen
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
| | - Haishen Jiang
- Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China; Kanfort (Jiangmen) Environmental Technology Co., Ltd, Jiangmen 529060, China
| | - Zhenhua Zhu
- Kanfort (Jiangmen) Environmental Technology Co., Ltd, Jiangmen 529060, China
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Wang Q, Zhang B, Yu S, Xiong J, Yao Z, Hu B, Yan J. Waste-Printed Circuit Board Recycling: Focusing on Preparing Polymer Composites and Geopolymers. ACS OMEGA 2020; 5:17850-17856. [PMID: 32743155 PMCID: PMC7391248 DOI: 10.1021/acsomega.0c01884] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 07/06/2020] [Indexed: 05/15/2023]
Abstract
The waste from end-of-life electrical and electronic equipment has become the fastest growing waste problem in the world. The difficult-to-treat waste-printed circuit boards (WPCBs), which are nearly 3-6 wt % of the total electronic waste, generate great environmental concern nowadays. For WPCB treatment and recycling, the mechanical-physical method has turned out to be more technologically and economically feasible. In this work, the mechanical-physical treatment and recycling technologies for WPCBs were investigated, and future research was directed as well. Removing electric and electronic components (EECs) from WPCBs is critical for their crushing and metal recovery; however, environmentally friendly and high-efficiency removal techniques need be developed. Concentrated metals rich in Cu, Al, Au, Pb, and Sn recovered from WPCBs need be further refined to add to their economic values. The low value-added nonmetallic fraction of waste-printed circuit boards (NMF-WPCBs) accounts for approximately 60 wt % of the WPCBs. From the perspective of environmental management, a zero-waste approach to recycling them should be developed to gain values. Preparing polymer composites and geopolymers offers many advantages and has potential applications in various fields, especially as construction and building materials. However, the mechanical and thermal properties of NMF-WPCBs composites should be further improved for preparing polymer composites. Surface modification or filler blending could be applied to improve the interfacial comparability between NMF-WPCBs and the polymer matrix. The NMF-WPCBs shows potential in preparing cement mortar and geological polymers, but the environmental safety resulting from metals needs to be taken into account. This study will provide a significant reference for the industrial recycling of NMF-WPCBs.
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Affiliation(s)
- Qin Wang
- State
Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
| | - Baogui Zhang
- Beijing
Institute of Space Mechanics & Electricity, Beijing 100094, China
| | - Shaoqi Yu
- College
of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Jingjing Xiong
- College
of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Zhitong Yao
- College
of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
- E-mail: (Z. Yao)
| | - Baoan Hu
- CCCC
(Tianjin) Eco-Environmental Protection Design & Research Institute
Co., Ltd., Tianjin 300461, China
| | - Jianhua Yan
- State
Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
- E-mail: (J. Yan)
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Zhu XN, Zhang LY, Dong SL, Kou WJ, Nie CC, Lyu XJ, Qiu J, Li L, Liu ZX, Wu P. Mechanical activation to enhance the natural floatability of waste printed circuit boards. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 109:222-230. [PMID: 32416564 DOI: 10.1016/j.wasman.2020.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 04/10/2020] [Accepted: 05/06/2020] [Indexed: 06/11/2023]
Abstract
The metal in the waste printed circuit boards (WPCBs) is an excellent secondary metal resource. WPCBs were ground to dissociate, and impurities in the dissociated product were removed by gradient flotation to recover valuable metals in this study. The effects of crushing methods on size composition and dissociation state of the crushed products were studied. Then the gradient flotation experiment was designed to verify the natural floatability of ground materials. Grinding test shows that impact crushing has greater grinding fineness (-0.074 mm) than shear crushing, which is 42.14% and 26.18% respectively with 5 min grinding. The flotation test results illustrate that the natural floatability of impurities increases with the grinding fineness, that is, the yield of floats increases without flotation reagents. For impact crushing and shear crushing, the floats yields are 38.48% and 31.75% respectively, accompanied by 70.53% and 65.46% impurity removal for ground materials with 5 min grinding. Subsequently, 21.61% and 26.35% of impurities can be further removed with the aid of collector. Finally, the recovery of Cu in concentrate reaches 67.84% and 65.75%, respectively. FT-IR proves that the excellent floatability of particles is caused by the significant hydrophobic group. Mechanical grinding has been proved to have double effects of improving dissociation and natural floatability.
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Affiliation(s)
- Xiang-Nan Zhu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
| | - Li-Ye Zhang
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Shu-Ling Dong
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Wen-Jia Kou
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Chun-Chen Nie
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Xian-Jun Lyu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Jun Qiu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Lin Li
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China
| | - Zhen-Xue Liu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
| | - Peng Wu
- College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
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Recovery of residual metals from fine nonmetallic fractions of waste printed circuit boards using a vibrated gas-solid fluidized bed. Sep Purif Technol 2018. [DOI: 10.1016/j.seppur.2018.06.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Tsunazawa Y, Hisatomi S, Murakami S, Tokoro C. Investigation and evaluation of the detachment of printed circuit boards from waste appliances for effective recycling. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 78:474-482. [PMID: 32559935 DOI: 10.1016/j.wasman.2018.06.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 05/29/2018] [Accepted: 06/11/2018] [Indexed: 06/11/2023]
Abstract
To establish an effective recycling process for waste appliances, the process of recovering printed circuit boards (PCBs) containing valuable elements in comminution was investigated and evaluated. The present study performed comminution tests using three different types of waste appliances: smartphones, microwave ovens and electrical rice cookers. Comminution tests showed that a drum-type agitation mill operated at a mid-range rotation speed could achieve a relatively high recovery ratio of PCBs and inhibit excessive breakage of PCBs. Following these experiments, simulations using the discrete element method with a particle-based rigid-body model were conducted to evaluate the comminution performance of the drum-type agitation mill. Experimental and simulation results confirm that the processes of detachment of PCBs from waste appliances and subsequent breakage can be expressed by kinetic equations related to collision energy. It is concluded from these results that the kinetic equations obtained in experiments and simulations can be used to evaluate the recovery process of PCBs from waste appliances.
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Affiliation(s)
- Yuki Tsunazawa
- Research Institute for Geo-Resources and Environment, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba-shi, Ibaraki 305-8567, Japan
| | - Shosei Hisatomi
- Department of Resources and Environmental Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Shinsuke Murakami
- Department of Systems Innovation, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Chiharu Tokoro
- Department of Resources and Environmental Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
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Gao X, Li Q, Qiu J. Hydrothermal modification and recycling of nonmetallic particles from waste print circuit boards. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 74:427-434. [PMID: 29317160 DOI: 10.1016/j.wasman.2018.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 12/07/2017] [Accepted: 01/02/2018] [Indexed: 06/07/2023]
Abstract
Nonmetallic particles recycled from waste print circuit boards (NPRPs) were modified by a hydrothermal treatment method and the catalysts, solvents, temperature and time were investigated, which affected the modification effect of NPRPs. The mild hydrothermal treatment method does not need high temperature, and would not cause secondary pollution. Further, the modified NPRPs were used as the raw materials for the epoxy resin and glass fibers/epoxy resin composites, which were prepared by pouring and hot-pressing method. The mechanical properties and morphology of the composites were discussed. The results showed that relative intensity of the hydroxyl bonds on the surface of NPRPs increased 58.9% after modification. The mechanical tests revealed that both flexural and impact properties of the composites can be significantly improved by adding the modified NPRPs. Particularly, the maximum increment of flexural strength, flexural modulus and impact strength of the epoxy matrix composites with 30% modified NPRPs is 40.1%, 80.0% and 79.0%, respectively. Hydrothermal treatment can modify surface of NPRPs successfully and modified NPRPs can not only improve the properties of the composites, but also reduce the production cost of the composites and environmental pollution. Thus, we develop a new way to recycle nonmetallic materials of waste print circuit boards and the highest level of waste material recycling with the raw materials-products-raw materials closed cycle can be realized through the hydrothermal modification and reuse of NPRPs.
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Affiliation(s)
- Xuehua Gao
- School of Materials Science and Engineering, Tongji University, Shanghai 201804, PR China
| | - Qisheng Li
- School of Materials Science and Engineering, Tongji University, Shanghai 201804, PR China
| | - Jun Qiu
- School of Materials Science and Engineering, Tongji University, Shanghai 201804, PR China; Key Laboratory of Advanced Civil Engineering Materials (Tongji University), Education of Ministry, Shanghai 201804, PR China.
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10
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Zhang G, He Y, Wang H, Zhang T, Wang S, Yang X, Xia W. New technology for recovering residual metals from nonmetallic fractions of waste printed circuit boards. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 64:228-235. [PMID: 28343744 DOI: 10.1016/j.wasman.2017.03.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 03/17/2017] [Accepted: 03/19/2017] [Indexed: 05/28/2023]
Abstract
Recycling of waste printed circuit boards is important for environmental protection and sustainable resource utilization. Corona electrostatic separation has been widely used to recycle metals from waste printed circuit boards, but it has poor separation efficiency for finer sized fractions. In this study, a new process of vibrated gas-solid fluidized bed was used to recycle residual metals from nonmetallic fractions, which were treated using the corona electrostatic separation technology. The effects of three main parameters, i.e., vibration frequency, superficial air flow velocity, and fluidizing time on gravity segregation, were investigated using a vibrating gas-solid fluidized bed. Each size fraction had its own optimum parameters. Corresponding to their optimal segregation performance, the products from each experiment were analyzed using an X-ray fluorescence (XRF) and a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS). From the results, it can be seen that the metal recoveries of -1+0.5mm, -0.5+0.25mm, and -0.25mm size fractions were 86.39%, 82.22% and 76.63%, respectively. After separation, each metal content in the -1+0.5 or -0.5+0.25mm size fraction reduced to 1% or less, while the Fe and Cu contents are up to 2.57% and 1.50%, respectively, in the -0.25mm size fraction. Images of the nonmetallic fractions with a size of -0.25mm indicated that a considerable amount of clavate glass fibers existed in these nonmetallic fractions, which may explain why fine particles had the poorest segregation performance.
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Affiliation(s)
- Guangwen Zhang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Shanghai Cooperative Centre for WEEE Recycling, Shanghai Second Polytechnic University, Shanghai 201209, China
| | - Yaqun He
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Shanghai Cooperative Centre for WEEE Recycling, Shanghai Second Polytechnic University, Shanghai 201209, China.
| | - Haifeng Wang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Tao Zhang
- Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Shanghai Cooperative Centre for WEEE Recycling, Shanghai Second Polytechnic University, Shanghai 201209, China
| | - Shuai Wang
- Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Xing Yang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Wencheng Xia
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
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Wang H, Zhang G, Zhang X, Xie W, He Y, Li H, Chen Q. Improving the efficiency of coal triboelectric separation by chemical conditioning. SEP SCI TECHNOL 2017. [DOI: 10.1080/01496395.2017.1280053] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Haifeng Wang
- Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Guangwen Zhang
- Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Xinxi Zhang
- Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Weining Xie
- Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Yaqun He
- Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
- Advanced Analysis & Computation Center, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Haisheng Li
- Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
| | - Qingru Chen
- Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining and Technology, Xuzhou, Jiangsu, China
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu, China
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Zhang G, Wang H, He Y, Yang X, Peng Z, Zhang T, Wang S. Triboelectric separation technology for removing inorganics from non-metallic fraction of waste printed circuit boards: Influence of size fraction and process optimization. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 60:42-49. [PMID: 27530083 DOI: 10.1016/j.wasman.2016.08.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/27/2016] [Accepted: 08/09/2016] [Indexed: 06/06/2023]
Abstract
Removing inorganics from non-metallic fraction (NMF) of waste printed circuit boards (WPCBs) is an effective mean to improve its usability. The effect of size fraction on the triboelectric separation of NMF of WPCBs was investigated in a lab triboelectric separation system and the separation process was optimized in this paper. The elements distribution in raw NMF collected from typical WPCBs recycling plant and each size fraction obtained by sieving were analyzed by X-ray fluorescence (XRF). The results show that the main inorganic elements in NMF are P, Ba, Mn, Sb, Ti, Pb, Zn, Sn, Mg, Fe, Ca, Cu, Al and Si. The inorganic content of each size fraction increased with the size decreasing. The metal elements are mainly distributed in -0.2mm size fraction, and concentrated in middle product of triboelectric separation. The loss on ignition (LOI) of positive product and negative product is higher than that of the middle product for the -0.355mm size fraction, while the LOI presents gradually increasing trend from negative to positive plate for the +0.355mm size fraction. Based on the separation results and mineralogical characterizations of each size fraction of NMF, the pretreatment process including several mineral processing operations was added before triboelectric separation and better separation result was obtained.
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Affiliation(s)
- Guangwen Zhang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Haifeng Wang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China.
| | - Yaqun He
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Xing Yang
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Zhen Peng
- School of Chemical Engineering and Technology, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China; Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Tao Zhang
- Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
| | - Shuai Wang
- Advanced Analysis & Computation Center, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
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He J, Duan C. Recovery of metallic concentrations from waste printed circuit boards via reverse floatation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 60:618-628. [PMID: 27866997 DOI: 10.1016/j.wasman.2016.11.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 11/04/2016] [Accepted: 11/08/2016] [Indexed: 05/22/2023]
Abstract
Efficient disposal of waste printed circuit boards (PCBs) is favorable toward recovering valuable components and reducing pollution. Reverse floatation was used to recover metallic concentrations from waste PCBs. Basic properties and mineralogical characteristics of raw PCBs were tested and analyzed. Results indicated that the grade of metallic concentrations declined as the size fraction of PCBs decreased. The major metallic elements found in PCBs were Cu, Pb, and Sn, as well as trace elements were also found in fine PCB particles. Kerosene and terpenic oil were used as the collector and frother in the floatation experiments. The effects of various operational factors, including the feeding concentration, aeration rate, and agitation speed of floatation machine, on the floatation performance of -0.25mm PCBs were experimentally studied to determine optimal range. The floatation results suggested that the yield of sinks and grade of metallic concentrations diminished significantly with the decrease of size fraction of PCBs. The maximum yields of sinks and highest grades of metallic concentrations were 48.72% and 16.86%, 47.96% and 14.61%, 44.36% and 8.81%, with the optimum recoveries of metallic concentrations of 94.69%, 90.06%, and 75.96% for size fractions of 0.125-0.25mm, 0.074-0.125mm, and -0.074mm PCBs, respectively. The recovery efficiency of metallic concentrations declined as the size fraction decreased. The efficient overall recovery performance of metallic concentrations from waste PCBs was obtained via reverse floatation. This study provides an alternative approach for disposing waste PCBs.
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Affiliation(s)
- Jingfeng He
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
| | - Chenlong Duan
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China.
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