International Journal of Minerals, Metallurgy and Materials

Article Title

Pyrolysis behaviour and combustion kinetics of waste printed circuit boards

Corresponding Author

Zhifeng Xu, E-mail: xzf_1@163.com

Corresponding Author 2

Jindi Huang, E-mail: hjd041@163.com


waste printed circuit board; pyrolysis mechanism; combustion; Gauss; peak fitting


The effective recycling of waste printed circuit boards (WPCBs) can conserve resources and reduce environmental pollution. This study explores the pyrolysis and combustion characteristics of WPCBs in various atmospheres through thermogravimetric and Gaussian fitting analyses. Furthermore, this study analyses the pyrolysis products and combustion processes of WPCBs through thermogravimetric and Fourier transform infrared analyses (TG–FTIR) and thermogravimetry–mass spectrometry (TG–MS). Results show that the pyrolysis and combustion processes of WPCBs do not constitute a single reaction, but rather an overlap of multiple reactions. The pyrolysis and combustion process of WPCBs is divided into multiple reactions by Gaussian peak fitting. The kinetic parameters of each reaction are obtained by the Coats–Redfern method. In an argon atmosphere, pyrolysis consists of the overlap of the preliminary pyrolysis of epoxy resin, pyrolysis of small organic molecules, and pyrolysis of brominated flame retardants. The thermal decomposition process in the O2 atmosphere is mainly divided into two reactions: brominated flame retardant combustion and epoxy combustion. This study provided the theoretical basis for pollution control, process optimization, and reactor design of WPCBs pyrolysis.


[1] Y.C. He and Z.M. Xu, Recycling gold and copper from waste printed circuit boards using chlorination process, RSC Adv., 5(2015), No. 12, p. 8957.

[2] J.B. Wang, J. Guo, and Z.M. Xu, An environmentally friendly technology of disassembling electronic components from waste printed circuit boards, Waste Manage., 53(2016), p. 218.

[3] Z. Sun, Y.P. Xiao, H. Agterhuis, J. Sietsma, and Y.X. Yang, Recycling of metals from urban mines - a strategic evaluation, J. Clean. Prod., 112(2016), p. 2977.

[4] J.W. Li, X. Han, R.X. Chai, F.Q. Cheng, M. Zhang, and M. Guo, Metal-doped (Cu,Zn)Fe2O4 from integral utilization of toxic Zn-containing electric arc furnace dust: An environment-friendly heterogeneous Fenton-like catalyst, Int. J. Miner. Metall. Mater., 27(2020), No. 7, p. 996.

[5] L. Xiao, P.W. Han, Y.L. Wang, G.Y. Fu, Z. Sun, and S.F. Ye, Silver dissolution in a novel leaching system: Reaction kinetics study, Int. J. Miner. Metall. Mater., 26(2019), No. 2, p. 168.

[6] Z.L. Liu, Z.H. Zhang, Z.L. Li, X.F. Xie, S.P. Zhong, Y.H. Li, Z.F. Xu, and H. Liu, 3D hierarchical iron-cobalt sulfide anchored on carbon fiber with abundant active short chain sulfur for high-efficiency capture of elemental mercury, Chem. Eng. J., 418(2021), art. No. 129442.

[7] L. Flandinet, F. Tedjar, V. Ghetta, and J. Fouletier, Metals recovering from waste printed circuit boards (WPCBs) using molten salts, J. Hazard. Mater., 213-214(2012), p. 485.

[8] G.B. Liang, J.H. Tang, W.P. Liu, and Q.F. Zhou, Optimizing mixed culture of two acidophiles to improve copper recovery from printed circuit boards (PCBs), J. Hazard. Mater., 250-251(2013), p. 238.

[9] K. Yan, L.P. Liu, H.X. Zhao, L. Tian, Z.F. Xu, and R.X. Wang, Study on extraction separation of thioarsenite acid in alkaline solution by \begin{document}$ {\rm{CO}}_3^{2-} $\end{document}-type tri-n-octylmethyl-ammonium chloride, Front. Chem., 8(2021), art. No. 592837.

[10] K.Q. Li, J. Chen, J.H. Peng, M. Omran, and G. Chen, Efficient improvement for dissociation behavior and thermal decomposition of manganese ore by microwave calcination, J. Clean. Prod., 260(2020), art. No. 121074.

[11] X.L. Xi, M. Feng, L.W. Zhang, and Z.R. Nie, Applications of molten salt and progress of molten salt electrolysis in secondary metal resource recovery, Int. J. Miner. Metall. Mater., 27(2020), No. 12, p. 1599.

[12] H.F. Zhao, H.Y. Yang, L.L. Tong, Q. Zhang, and Y. Kong, Biooxidation-thiosulfate leaching of refractory gold concentrate, Int. J. Miner. Metall. Mater., 27(2020), No. 8, p. 1075.

[13] S.H. Yin, L.M. Wang, A.X. Wu, X. Chen, and R.F. Yan, Research progress in enhanced bioleaching of copper sulfides under the intervention of microbial communities, Int. J. Miner. Metall. Mater., 26(2019), No. 11, p. 1337.

[14] Z.Y. Ma, Y. Liu, J.K. Zhou, M.D. Liu, and Z.Z. Liu, Recovery of vanadium and molybdenum from spent petrochemical catalyst by microwave-assisted leaching, Int. J. Miner. Metall. Mater., 26(2019), No. 1, p. 33.

[15] H.H. Yi, Z.Y. Yang, X.L. Tang, S.Z. Zhao, F.Y. Gao, J.G. Wang, Y.H. Huang, K. Yang, Y.R. Shi, and X.Z. Xie, Variations of apparent activation energy based on thermodynamics analysis of zeolitic imidazolate frameworks including pyrolysis and combustion, Energy, 151(2018), p. 782.

[16] H.D. Wang, S.H. Zhang, B. Li, D.A. Pan, Y.F. Wu, and T.Y. Zuo, Recovery of waste printed circuit boards through pyrometallurgical processing: A review, Resour. Conserv. Recycl., 126(2017), p. 209.

[17] B. Ebin and M.I. Isik, Pyrometallurgical processes for the recovery of metals from WEEE, [in] A. Chagnes, C. Ekberg, T. Retegan, G. Cote, and M. Nilsson, eds., WEEE Recycling, Elsevier, 2016, p.107.

[18] C. Hagelüken, Recycling of electronic scrap at umicore's integrated metals smelter and refinery, World Metall. ERZMETALL, 59(2006), No. 3, p. 152.

[19] K.Q. Li, Q. Jiang, L. Gao, J. Chen, J.H. Peng, S. Koppala, M. Omran, and G. Chen, Investigations on the microwave absorption properties and thermal behavior of vanadium slag: Improvement in microwave oxidation roasting for recycling vanadium and chromium, J. Hazard. Mater., 395(2020), art. No. 122698.

[20] Q.M. Wang, S.S. Wang, M. Tian, D.X. Tang, Q.H. Tian, and X.Y. Guo, Relationship between copper content of slag and matte in the SKS copper smelting process, Int. J. Miner. Metall. Mater., 26(2019), No. 3, p. 301.

[21] C. Quan, A.M. Li, and N.B. Gao, Research on pyrolysis of PCB waste with TG-FTIR and Py-GC/MS, J. Therm. Anal. Calorim., 110(2012), No. 3, p. 1463.

[22] C.C. Nie, Y.Y. Wang, H. Zhang, Y.K. Zhang, Y.Q. Zhang, Z.Q. Yan, B. Li, X.J. Lyu, Y.J. Tao, J. Qiu, L. Li, G.W. Zhang, and X.N. Zhu, Cleaner utilization of non-metallic components in separation tailings of waste printed circuit board: Pyrolysis oil, calorific value and building aggregate, J. Clean. Prod., 258(2020), art. No. 120976.

[23] R.T. Gao and Z.M. Xu, Pyrolysis and utilization of nonmetal materials in waste printed circuit boards: Debromination pyrolysis, temperature-controlled condensation, and synthesis of oil-based resin, J. Hazard. Mater., 364(2019), p. 1.

[24] K.Q. Li, G. Chen, X.T. Li, J.H. Peng, R. Ruan, M. Omran, and J. Chen, High-temperature dielectric properties and pyrolysis reduction characteristics of different biomass-pyrolusite mixtures in microwave field, Bioresour. Technol., 294(2019), art. No. 122217.

[25] R.R. Rajagopal, R. Rajarao, and V. Sahajwalla, High temperature transformations of waste printed circuit boards from computer monitor and CPU: Characterisation of residues and kinetic studies, Waste Manage., 57(2016), p. 91.

[26] R.T. Gao, Y. Liu, and Z.M. Xu, Synthesis of oil-based resin using pyrolysis oil produced by debromination pyrolysis of waste printed circuit boards, J. Clean. Prod., 203(2018), p. 645.

[27] X.W. Li, Q.Q. Mei, X.H. Dai, and G.J. Ding, Effect of anaerobic digestion on sequential pyrolysis kinetics of organic solid wastes using thermogravimetric analysis and distributed activation energy model, Bioresour. Technol., 227(2017), p. 297.

[28] R.R. Xiao, W. Yang, X.S. Cong, K. Dong, J. Xu, D.F. Wang, and X. Yang, Thermogravimetric analysis and reaction kinetics of lignocellulosic biomass pyrolysis, Energy, 201(2020), art. No. 117537.

[29] F. Rego, A.P. Soares Dias, M. Casquilho, F.C. Rosa, and A. Rodrigues, Pyrolysis kinetics of short rotation coppice poplar biomass, Energy, 207(2020), art. No. 118191.

[30] H. Fei, J.M. Shi, Y.L. Li, and Y. Liu, Precipitation characteristics of alkali metal of aquatic biomass in Poyang Lake during pyrolysis, Nonferrous Met. Sci. Eng., 8(2017), No. 1, p. 139.

[31] C. Zou, L.Y. Wen, J.X. Zhao, and R.M. Shi, Interaction mechanism between coal combustion products and coke in raceway of blast furnaces, J. Iron Steel Res. Int., 24(2017), No. 1, p. 8.

[32] H.L. Chiang and K.H. Lin, Exhaust constituent emission factors of printed circuit board pyrolysis processes and its exhaust control, J. Hazard. Mater., 264(2014), p. 545.

[33] J.E. White, W.J. Catallo, and B.L. Legendre, Biomass pyrolysis kinetics: A comparative critical review with relevant agricultural residue case studies, J. Anal. Appl. Pyrol., 91(2011), No. 1, p. 1.

[34] S. Sobek and S. Werle, Kinetic modelling of waste wood devolatilization during pyrolysis based on thermogravimetric data and solar pyrolysis reactor performance, Fuel, 261(2020), art. No. 116459.

[35] A. Gupta, S.K. Thengane, and S. Mahajani, Kinetics of pyrolysis and gasification of cotton stalk in the central parts of India, Fuel, 263(2020), art. No. 116752.

[36] K.Q. Li, Q. Jiang, G. Chen, L. Gao, J.H. Peng, Q. Chen, S. Koppala, M. Omran, and J. Chen, Kinetics characteristics and microwave reduction behavior of walnut shell-pyrolusite blends, Bioresour. Technol., 319(2021), p. 124172.

[37] J.J. Baeza-Baeza, C. Ortiz-Bolsico, and M.C. García-Álvarez-Coque, New approaches based on modified Gaussian models for the prediction of chromatographic peaks, Anal. Chim. Acta, 758(2013), p. 36.

[38] S. Bernard, K. Fiaty, D. Cornu, P. Miele, and P. Laurent, Kinetic modeling of the polymer-derived ceramics route: Investigation of the thermal decomposition kinetics of poly[B-(methylamino)borazine] precursors into boron nitride, J. Phys. Chem. B, 110(2006), No. 18, p. 9048.

[39] T.J. Chen, L.Y. Li, R.D. Zhao, and J.H. Wu, Pyrolysis kinetic analysis of the three pseudocomponents of biomass–cellulose, hemicellulose and lignin, J. Therm. Anal. Calorim., 128(2017), No. 3, p. 1825.

[40] X.J. Wang, J.Q. Wu, Y.M. Li, C.J. Zhou, and C.H. Xu, Pyrolysis kinetics and pathway of polysiloxane conversion to an amorphous SiOC ceramic, J. Therm. Anal. Calorim., 115(2014), No. 1, p. 55.

[41] K. Ding, Numerical Simulation of Pyrolysis Characteristics and Process of Combustible Solid Waste [Dissertation], Southeast University, Nanjing, 2017, p 64.

[42] Y.F. Shen, X.M. Chen, X.L. Ge, and M.D. Chen, Thermochemical treatment of non-metallic residues from waste printed circuit board: Pyrolysis vs. combustion, J. Clean. Prod., 176(2018), p. 1045.

[43] Z.W. Ye, F. Yang, W.X. Lin, S.P. Li, and S.Y. Sun, Improvement of pyrolysis oil obtained from co-pyrolysis of WPCBs and compound additive during two stage pyrolysis, J. Anal. Appl. Pyrolysis, 135(2018), p. 415.

[44] C.H. Zhao, X.P. Zhang, and L. Shi, Catalytic pyrolysis characteristics of scrap printed circuit boards by TG–FTIR, Waste Manage., 61(2017), p. 354.

[45] X. Chen, Infrared Absorption Spectroscopy and Application, Shanghai Jiaotong University Press, Beijng, 1993, p. 46.

[46] K.H. Lin and H.L. Chiang, Liquid oil and residual characteristics of printed circuit board recycle by pyrolysis, J. Hazard. Mater., 271(2014), p. 258.

[47] B. Janković, N. Manić, D. Stojiljković, and V. Jovanović, TSA-MS characterization and kinetic study of the pyrolysis process of various types of biomass based on the Gaussian multi-peak fitting and peak-to-peak approaches, Fuel, 234(2018), p. 447.

[48] L. Huang, Y.C. Chen, G. Liu, S.N. Li, Y. Liu, and X. Gao, Non-isothermal pyrolysis characteristics of giant reed (Arundo donax L.) using thermogravimetric analysis, Energy, 87(2015), p. 31.