Pyrolysis Characteristics and Recovery of the Metallic and Nonmetallic Materials in Wasted Printed Circuit Boards

Abstract:

A typical printed circuit boards (PCBs) has been investigated by using thermo-gravimetric analyser to study its pyrolysis characteristics, the results indicate that the maximum weight loss rate occurs at temperature between 320°C and 360°C. A higher heating rate results in higher initial, final, peak temperature, and a longer process of significant weight loss. At the same pyrolysis temperature, heating rate has little effect on the total weight loss. In addition, 1kg PCBs based FR-4 was pyrolyzed in a fixed-bed reactor. The pyrolysis residues are very friable, the organic, glass fiber and metallic fractions can easily be separated, and the electrical components can easily be removed from the remains. Considering energy-saving, better control and design of the pyrolysis process, the optimal pyrolysis parameters were suggested at heating rate 10°C/min, final pyrolysis temperature 500°C and holding time 30 min.

• Periodical: Advanced Materials Research (Volumes 347-353)
• Pages: 2107-2111
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.347-353.2107
• Online since: October 2011
• Authors: Hong Ting Ma, Guo Li Yang, Su Feng Hao
• Keywords: Printed Circuit Board (PCB), Pyrolysis Characteristic, Pyrolysis Parameter, Separation

References

[1] R.G. Reddy, R.K. Mishra, in: Proceedings of the Eleventh IPMI Conference, USA: Int Precious Metals Inst 1987, 135–146.

[2] T. Oishi, K. Koyama, S. Alam et al, Recovery of high purity copper cathode from PCBs using ammoniacal sulfate or chloride solutions, J. Hydrometallurgy. 89 (2007) 82–88.

DOI: 10.1016/j.hydromet.2007.05.010

[3] T. Bhaskar, J. Kaneko, A. Muto et al, Pyrolysis studies of PP/PE/PS/PVC/HIPS-Br plastics mixed with PET and dehalogenation (Br, Cl) of the liquid products, J. Anal. Appl. Pyrol. 72 (2004) 27-33.

DOI: 10.1016/j.jaap.2004.01.005

[4] M. Brebuet, T. Bhaskar, K. Murai et al, Removal of nitrogen, bromine, and chlorine from PP/PE/PS/PVC/ABSeBr pyrolysis liquid products using Fe- and Ca-based catalysts, J. Polym. Degrad. Stabil. 87 (2005) 225-230.

DOI: 10.1016/j.polymdegradstab.2004.08.008

[5] W. Hall and P.T. Williams, Feedstock recycling of polymers by pyrolysis in a fluidised bed. J. Appl. Pyrol. 77 (2006) 75-82.

[6] F. Barontini, K. Marsanich, L. Petarca et al, Thermal Degradation and Decomposition Products of Electronic Boards Containing BFRs, J. Ind. Eng. Chem. Res. 44 (2005) 4186-4199.

DOI: 10.1021/ie048766l

[7] W.J. Hall and P.S. Williams, Separation and recovery of materials from scrap printed circuit boards, J. Resour Conserv. Recy. 51 (2007) 691-709.

DOI: 10.1016/j.resconrec.2006.11.010

[8] F. Barontini and V. Cozzani, Formation of hydrogen bromide and organobrominated compounds in the thermal degradation of electronic boards, J. Anal. Appl. Pyrol. 77 (2006) 41-55.

DOI: 10.1016/j.jaap.2006.01.003