Cleaner utilization of non-metallic components in separation tailings of waste printed circuit board: Pyrolysis oil, calorific value and building aggregate

Abstract

The resource utilization of non-metallic components (NMC) in waste printed circuit boards (WPCBs) was concerned in this study. Pyrolysis oil, calorific value and building materials in NMC were recovered and utilized. Organic matter in NMC was recycled in the form of pyrolysis oil by pyrolysis treatment. The pyrolysis temperature was determined by thermogravimetric analysis. The composition of pyrolysis oil was analyzed by GC-MS. Thermogravimetric analysis shows that 300–400 °C is the main temperature range for the formation of pyrolysis oil, and the weight loss reaches 20.58%. Further, weight loss only achieves 6.38% within 400–800 °C. The GC-MS results show that the main components are phenols, which can be used for the synthesis of oil-based resins. In addition, the calorific value of pyrolysis residues was measured. The results show that the calorific value of pyrolysis residues obtained at 400 °C and 800 °C reaches 4.62 MJ/kg and 3.76 MJ/kg respectively in aerobic conditions. Finally, the residue without calorific value was prepared into building material with cement, and the compressive strength is proven to reach 9.43 MPa. This study provides a practical approach to the reutilization of NMC in WPCBs.