为研究废弃印刷线路板的热解特性,确定金属和非金属分离的热解最佳参数,用差热-热重联用分析仪对FR-4型印刷线路板进行了热失重分析,并对影响废弃印刷线路板中金属和非金属分离效果的升温速率、颗粒尺寸、热解终温和保温时间等主要因素进行了实验研究。结果表明,FR-4型线路板在320~360℃区间热失重速率达到最大值;升温速率越高,热解起始温度、终止温度和失重峰温也越高,显著失重过程持续的时间越长;当热解终温相同时,升温速率对FR-4型线路板的热失重率影响很小。综合考虑FR-4型废弃印刷线路板中金属和非金属的分离效果、热解装置的设计、热解过程的能耗以及运行过程的控制等因素,最佳热解参数建议设定为升温速率为10℃/min,热解终温为500℃,保温时间取30 min为宜。
In order to study the pyrolysis characteristics of waste printed circuit board(PCB) and determine the optimal operating parameters for separating metals from nonmetallic materials in the circuit boards,a typical printed circuit board(FR-4) has been investigated by using a thermo-gravimetric analyser(TGA).Those most effective factors to the final separation are also studied experimentally,such as heating rate,particle size,final pyrolysis temperature,and hold time.The results indicate that the maximum weight loss rate occurs in a range of 320~360 ℃ for the FR-4 board.A higher heating rate will result in higher initial,finial and maximum temperature,and longer process of significant weight loss.At the same pyrolysis temperature,the heating rate has little effect on the total weight loss.According to the experimental results and considering energy-saving,running,design of the pyrolysis device,and separating the metallic from nonmetallic materials in waste printed circuit board,the optimal pyrolysis parameters are suggested,i.e.heating rate is 10 ℃/min,final pyrolysis temperature is 500 ℃ with a hold time of 30 min.