SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2021, Vol. 40 ›› Issue (12): 262-268.DOI: 10.1016/j.cjche.2020.11.008

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Efficient recovery of valuable metals from waste printed circuit boards by microwave pyrolysis

Yubo Liu1,2, Jialiang Zhang1,2,4, Xu Yang2, Wenguang Yang2, Yongqiang Chen1,2,4, Chengyan Wang1,2,3,4   

  1. 1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China;
    2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China;
    3. School of Metallurgy Engineering, JiangXi University of Science and Technology, Ganzhou 341000, China;
    4. Beijing Key Laboratory of Green Recycling and Extraction of Metals, Beijing 100083, China
  • Received:2020-04-30 Revised:2020-10-19 Online:2022-01-14 Published:2021-12-28
  • Contact: Jialiang Zhang,E-mail:jialiangzhang@ustb.edu.cn;Chengyan Wang,E-mail:chywang@yeah.net
  • Supported by:
    This work was supported by the National Key Research and Development Program of China (2019YFC1908404), the National Natural Science Foundation of China (Nos. 51834008, 51874040, 52034002), the Guangxi Innovation-Driven Development Project (AA18242042-1) and the Fundamental Research Funds for the Central Universities (FRF-TP-18-020A3).

Efficient recovery of valuable metals from waste printed circuit boards by microwave pyrolysis

Yubo Liu1,2, Jialiang Zhang1,2,4, Xu Yang2, Wenguang Yang2, Yongqiang Chen1,2,4, Chengyan Wang1,2,3,4   

  1. 1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China;
    2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China;
    3. School of Metallurgy Engineering, JiangXi University of Science and Technology, Ganzhou 341000, China;
    4. Beijing Key Laboratory of Green Recycling and Extraction of Metals, Beijing 100083, China
  • 通讯作者: Jialiang Zhang,E-mail:jialiangzhang@ustb.edu.cn;Chengyan Wang,E-mail:chywang@yeah.net
  • 基金资助:
    This work was supported by the National Key Research and Development Program of China (2019YFC1908404), the National Natural Science Foundation of China (Nos. 51834008, 51874040, 52034002), the Guangxi Innovation-Driven Development Project (AA18242042-1) and the Fundamental Research Funds for the Central Universities (FRF-TP-18-020A3).

Abstract: The recycling of waste printed circuit board (WPCBs) is of great significance for saving resources and protecting the environment. In this study, the WPCBs were pyrolyzed by microwave and the contained valuable metals Cu, Sn and Pb were recovered from the pyrolyzed WPCBs. The effect of pyrolysis temperature and time on the recovery efficiency of valuable metals was investigated. Additionally, the characterization for morphology and surface elemental distribution of pyrolysis residues was carried out to investigate the pyrolysis mechanism. The plastic fiber boards turned into black carbides, and they can be easily separated from the metals by manual. The results indicate that 91.2%, 96.1% and 94.4% of Cu, Sn and Pb can be recovered after microwave pyrolysis at 700 ℃ for 60 minutes. After pyrolysis, about 79.8% (mass) solid products, 11.9% (mass) oil and 8.3% (mass) gas were produced. These gas and oil can be used as fuel and raw materials of organic chemicals, respectively. This process provides an efficient and energy-saving technology for recovering valuable metals from WPCBs.

Key words: Recovery, Waste printed circuit boards (WPCBs), Microwave pyrolysis, Valuable metals, Waste treatment

摘要: The recycling of waste printed circuit board (WPCBs) is of great significance for saving resources and protecting the environment. In this study, the WPCBs were pyrolyzed by microwave and the contained valuable metals Cu, Sn and Pb were recovered from the pyrolyzed WPCBs. The effect of pyrolysis temperature and time on the recovery efficiency of valuable metals was investigated. Additionally, the characterization for morphology and surface elemental distribution of pyrolysis residues was carried out to investigate the pyrolysis mechanism. The plastic fiber boards turned into black carbides, and they can be easily separated from the metals by manual. The results indicate that 91.2%, 96.1% and 94.4% of Cu, Sn and Pb can be recovered after microwave pyrolysis at 700 ℃ for 60 minutes. After pyrolysis, about 79.8% (mass) solid products, 11.9% (mass) oil and 8.3% (mass) gas were produced. These gas and oil can be used as fuel and raw materials of organic chemicals, respectively. This process provides an efficient and energy-saving technology for recovering valuable metals from WPCBs.

关键词: Recovery, Waste printed circuit boards (WPCBs), Microwave pyrolysis, Valuable metals, Waste treatment