废旧电路板与碳酸钙共热解脱卤的研究

Study on copyrolysis and dehalogenation of waste printed circuit boards and calcium carbonate

采用热重分析仪和石英管式炉热解反应器,分别对以酚醛树脂为基板的废旧电路板和混合碳酸钙后的废旧电路板进行热解实验研究,着重考察了添加碳酸钙后的酚醛树脂基板废旧电路板热解特性及添加量不同对卤素脱除效果的影响。实验结果表明,碳酸钙的加入对废旧电路板的降解行为和热解油的基本组成没有明显的影响,但热解油的各组分含量有所差异;随着热解温度的提高或者CaCO3含量的增多,卤素可以更多地由有机卤向无机卤转变并束缚在固体残渣中,由此得到较好的脱卤效果。当60%PR-WPCBs与40%CaCO3共热解,热解油中的溴化物也减少了7.6%。在600℃等量CaCO3与PR-WPCBs共热解时生成75.6%无机卤,其中70.62%束缚于固体残渣中,可见达到较好的脱卤效果。

Pyrolysis experiments of phenolic-resin-based waste printed circuit boards （PR-WPCBs）, the mixture samples of PR-WPCBs and calcium carbonate （CaCO3） were carried out by thermogravimetric analyzer and a tubuler pyrolysis reactor. The present work investigated pyrolysis characteristics and the effect on dehaloge- nation by adding different proportions of CaCO3 under low vacuum. The results indicated that ： （ 1 ） There was no negative effect on the degradation behavior and pyrolysis products of PR-WPCBs by adding calcium carbonate. However, the concentration of compositions of pyrolytic oil is different. （2） With the pyrolysis temperature or calcium carbonate increasing, halogen could more transfer from organic halides to inorganic halides and were bound at solid residua, so that the effect of dehalogenation was better. （3） When 60% PR-WPCBs copyrolysis with 40% CaCO3 , the organobrominated compound of pyrolytic oil reduced 7.6%. （4）When PR-WPCBs copyrolysised with equal weight CaCO3 ,75.6% inorganic halides was formed and 70.62% inorganic halides was remained at solid residue. It showed that the influence of CaCO3 on dehalogenation was better.