Study on the Promotion Effect of Microwave-Metal Discharge on the Microwave Pyrolysis of Electronic Waste

Abstract:

This paper discussed the role of microwave-metal discharge on the microwave induced pyrolysis of electronic waste. Two kinds of waste printed circuit boards (WPCB) were selected as the representatives of electronic waste and their pyrolysis processes under both conventional and microwave heating schemes were studied comparatively to reveal the effect of metal discharge. The copper-clad laminated printed circuit board (PCB) is deficient in absorbing microwaves, leading to inefficient microwave pyrolysis of this kind of electronic waste. The discharge caused by introducing metalliferous materials with metal tips or corners in the electromagnetic fields can result in high local temperature and complement the deficiency in the microwave absorption. The pyrolytic process can be promoted greatly by the thermal effect of discharge in the beginning and the enhanced consequent wave-absorption capacity as a result of the generated pyrolytic coke.

• Periodical: Advanced Materials Research (Volume 1088)
• Pages: 843-847
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1088.843
• Online since: February 2015
• Authors: Jing Sun*, Wen Long Wang, Chun Yuan Ma, Qin Yan Yue
• Keywords: Efficient, Microwave Pyrolysis, Microwave-Metal Discharge, Wave Absorption, WEEE

References

[1] C. Hicks, R. Dietmar, et al, The recycling and disposal of electrical and electronic waste in China-legislative and market responses. Environ. Impact Assess. Review, 25 (2005), 459-471.

DOI: 10.1016/j.eiar.2005.04.007

[2] W.Z. He, G.M. Li, et al. WEEE recovery strategies and the WEEE treatment status in China. J. Hazard. Mater. 136 (2006), 502-512.

DOI: 10.1016/j.jhazmat.2006.04.060

[3] T.J. Byers, in: Printed Circuit Board Design with Microcomputer, McGraw-Hill, New York, (1991).

[4] F.L. Yan, Metals Recovery from Scrap IC Board. Energy Resource Laboratory, (1998).

[5] J. Sun, W.L. Wang, et al. Waste printed circuit boards reclamation by microwave-induced pyrolysis and featured mechanical processing. Ind. Eng. Chem. Res., 50 (2011), 11763-11769.

DOI: 10.1021/ie2013407

[6] J.A. Menéndez, E.J. Juárez-Pérez, et al. Ball lightning plasma and plasma arc formation during the microwave heating of carbons. Carbon, 49 (2011), 346-349.

DOI: 10.1016/j.carbon.2010.09.010

[7] J. Sun, W.L. Wang, et al. Study of the transference rules for Br in WPCBs during microwave-induced pyrolysis. J. of Air & Waste Manage. Associ, 61 (2011), 535-542.

[8] W.L. Wang, Z. Liu, et al. Experimental Study on the Heating Effects of Microwave Discharge Caused by Metals., AIChE Journal, 58 (2012), 3852-3857.

DOI: 10.1002/aic.13766

[9] J. Sun, W.L. Wang, et al. Kinetic study of pyrolysis in waste printed circuit boards subject to conventional and microwave heating. Energies, 5 (2012), 3295-3306.

DOI: 10.3390/en5093295

[10] M.H. Yang, The dielectrics characteristics of base materials for high frequency printed circuit boards and the progress in modification. Copper foil & Laminate, 4 (2009), 27-31. In Chinese.

[11] A.L. Cao and L. Tian, The effects of dielectric constant and dielectric loss tangent on the PCB'S characteristic impedance. ZIDONGHUA YU YIQI YIBIAO, 6 (2003), 47-48. In Chinese.

[12] J. Sun, W.L. Wang, et al.: Ind. Eng. Chem. Res., Study on the coupled effect of wave absorption and metal discharge generation under microwave irradiation. 53 (2014), 2042–(2051).

DOI: 10.1021/ie403556w