Pyrolysis Of Organic Material Resource Recycling Waste Printed Circuit Board

Currently, all sorts of more than 100 tons of waste printed circuit board (PCB) materials were produced in all the world every year, and 30% of the organic matter and 40% of metal materials in printed circuit board can be recycled. It's an important topic that the metal and organic materials' comprehensive utilization of waste printed circuit board in resources supply and demand contradiction growing days.Metal materials'recycling of PCB has achieved rapid development and industrialization, but utilization of nonmetallic material is still serious lagged.These waste nonmetallic materials will do serious bad to environment and human health if they couldn't be handled properly.The metal components and non-metal components of PCB can be recycled by pyrolysis.The status of recycling a typical kind of FR-4 printed circuit boards (PCB) by pyrolysis in China and overseas is reviewed. The characteristics and products during pyrolysis of samples have been investigated. Effect of the pyrolysis atmosphere, temperature, heating rate, vacuum and holding time on the pyrolysis were discussed and the optimum pyrolysis process is decided.Methods of pyrolysis oil extraction from FR-4 type Printed Circuit Boards were compared, and a new method "Alkali treatment-Acidification-Extraction-Vacuum distillation" was concluded. The separated components were characterized by gas chromatograph-ma-ss spectrometer (GC-MS). The pyrolysis oil is extracted from FR-4 type printed circuit boards with this method, the total obtained phenols is 62.0% of the pyrolysis oil, and the best purity for phenol reached 96.51%. using this method, the experimental equipment is simplified, the recovery rate is improved, and phenols won't be oxidized in the process of extraction.According to the extracts nature of the pyrolysis oil, thermosetting phenolic resins were synthesized using the extracts of pyrolysis oil, used as cementing compound. For the problems that the ordinary phenolic resins(PFs) were used as refractory binder, combined with structural characteristics ablation-resistant resin should have, feasibility of boric acid, molybdic acid and silicic acid-modified PFs were studied. On this basis, combined a few modified PF's ideological syntheses process, through the orthogonal test and analysis and discussion of impact of various factors on the synthesis process, in accordance with the actual situation the optimum process parameters were determined. By the analyses of GC-MS, solid content, the rate of residual carbon, TGA curves and viscosity, the modified PFs'properties were investigated. The indicators of boric acid, molybdic acid and silicic acid modified thermosetting PFs meet standard YB/T 4131-2005.