Waste printed circuit boards (WPCBs) contain lots of valuable resources together with plenty of hazardous materials, which are considered both an attractive secondary resource and an environmental contaminant. In this study, a new technology for the recovery of solder from WPCBs using an ionic liquid of 1-ethyl-3-methylimizadolium tetrafluoroborate ([EMIM+][BF4−]) as a heating medium was investigated. Experimental results indicate that the separation of solder from WPCBs is complete when WPCBs are heated at 240°C and [EMIM+][BF4−] is stirred at 150 rpm for 10 min. By observing the cross sections of WPCBs before and after treatment with the ionic liquid, it has been found that there is a initial delaminating phenomenon for WPCBs, which implies that [EMIM+][BF4−] can dissolve bromine epoxy resins of WPCBs to some extent. This clean and non-polluting technology offers a new way of recycling valuable materials from WPCBs and prevents the environmental pollution by WPCBs effectively.
DuanHBHouKLiJHZhuXD (2011) Examining the technology acceptance for dismantling of waste printed circuit boards in light of recycling and environmental concerns. Journal of Environmental Management92: 392–399.
3.
FrankMC (2002) Report on the recycling of computer circuit boards. Available at: www.p2pays.org/ref/02/01469.pdf (accessed 30 August 2006).
4.
GaoR (2007) Research on with Dismantling of PCB Mounted Electronic Components. Masters Thesis, China Academy of Machinery Science and Technology, China [in Chinese].
5.
GockmannK (1992) Recycling of copper. CIM Bulletin85:150–156.
6.
GuWXHuanCYangCZhuPLiCH (2008) Recovery of aurum from waste printed circuit boards. Environmental Science & Technology31: 98–100.
7.
GuoJLiJRaoQLXuZM (2008) Phenolic molding compound filled with nonmetals of waste PCBs. Environmental Science & Technology42: 624–628.
8.
HaoJWangHFSongSLWangXY (2008) Status of recycling scrap printed circuit boards by pyrolysis. China Resources Comprehensive Utilization26: 30–33.
9.
HarutaTNaganoTKishimotoTYamadaYYunoT (1991) Process for removing tin and tin-lead alloy from copper substrates. US Patent Issued on 30July1991.
10.
HuangHPanJLiuZSongSLiuG (2007) Study on disassembling approaches of electronic components mounted on PCBs. In: 14th CIRP Conference on Life Cycle Engineering for Sustainable Manufacturing Businesses, Waseda University, Tokyo, Japan, 11-13 June, 2007, Part 3, B3, 263–266
11.
KimEYKimMSLeeJCYooKKJeongJK (2010) Leaching behavior of copper using electro-generated chlorine in hydrochloric acid solution. Hydrometallurgy100: 95–102.
12.
KubisaP (2009) Ionic liquids as solvents for polymerization processes – progress and challenges. Progress in Polymer Science34: 1333–1347.
13.
KuiHJieGZhenmingX (2009) Recycling of waste printed circuit boards: A review of current technologies and treatment status in China. Journal of Hazardous Materials164: 399–408
14.
LiRX (2005) Green Solvents: Synthesis and Application of Ionic Liquids. Beijing: Chemical Industry Press.
15.
LiJTianBLiuTLiuHWenXHondaSh (2006) Status quo of e-waste management in mainland China. Journal of Material Cycles and Waste Management8: 13–20.
16.
LiJLuHZGuoJXuZMZhouYH (2007) Recycle technology for recovering resources and products from waste printed circuit boards. Environmental Science & Technology41: 1995–2000.
17.
LiHJSunSYDengFLongLS (2009) Discussion on dealing with printed circuit boards scrap by pvrolysis method. China Resources Comprehensive Utilization27: 15–18.
SedaKDefneKUğurAÖnerH (2007) A review of ionic liquids towards supercritical fluid applications. Journal. of Supercritical Fluids43: 150–180.
20.
WaLXiangDMouPDuanG (2005) Disassembling approaches and quality assurance of electronic components mounted on PCBs. In: Proceedings of the 2005 IEEE International Symposium on Electronics and the Environment, New Orleans, LA, USA, 16-19 May 2005 pp. 116–120. New York, NY, USA: Institute of Electrical and Electronics Engineers (IEEE).
21.
WangYGaoDLiangD (2011) Study on the synthesis of 1-ethyl-3-methylimida-zolium tetrafluoroborate. Guangzhou Chemical39: 81–83.
22.
ZhengYSMoQ (2009) Simulation calculation of structure property of 1-ethy-1-3- methylimidazolium tetrafluroorate ionic liquid. Journal of Guanxi University of Technology20: 7–9.
23.
ZhongHSongSLiuZZhangH (2008) Research on disassembling electronic components on discarded PCBs with hot fluid. Machine Design & Manufacture4: 101–103 [in Chinese].
24.
ZhouYHQiuKQ (2010) A new technology for recycling materials from waste printed circuit boards. Journal of Hazardous Materials175: 823–828.
25.
ZhuPGuGB (2002) Recovery of gold and copper from waste printed circuits. Chinese Journal of Rare Metals26: 214–216.
26.
ZhuPFanZYLinJLiuQQianGRZhouM (2009) Enhancement of leaching copper by electro-oxidation from metal powders of waste printed circuit board. Journal of Hazardous Materials309: 746–750.
