废印刷线路板粉碎处理中热解污染的试验研究

Measurement of pyrolysis contamination during crushing of waste printed circuit boards

为减少废印刷线路板粉碎时的热解污染。改善其环境友好性，进行了试验研究。在冲击试验中，引入红外热成像技术模拟、估算局部温度；联合使用热重及裂解-Fourier变换红外谱，分析了FR-4线路板的热解特性和产物组分。试验发现：冲击粉碎中局部高温可达300～350℃，而在270～350℃范围内FR-4线路板存在剧烈的热解失重。热解产物可能包括澳代烃、甲苯、澳苯、澳甲苯及少量的酚、甲酚、澳酚等。局部高温是造成粉碎中热解污染物释放和积累的根本原因，因此，有必要改进粉碎工艺使局部温升限制在裂解温度以下。

The crushing of waste printed circuit boards （PCBs） can result in pyrolysis and environmental pollution. The transient temperatures during crushing were measured with a thermal infrared imaging technology. The resulting pyrolysis of FR 4 PCB was also measured with thermal gravity analysis and pyrolysis-Fourier transform infrared spectroscopy. The surface temperatures reached 300 - 350℃ for over 3 seconds, the FR-4 quickly decomposed between 270 - 350℃. The pyrolysis products included borminated hydrocarbons, methylbenzene, bromobenzene, bromomethyl benzene and some hydroxybenzene, cresol and bromophenol. The tests show that temperatures during crushing cause the production of a variety of organic contaminants. Therefore, the crushing process should be modified to reduce the temperatures and the pyrolysis, so as to reduce the environmental effects.