碳酸钙强化酚醛型线路板热解脱溴  

Pyrolytic debromination of phenolic resin type PCB enhanced by calcium carbonate

作　　者：关国强[1,2] 周文贤[1,2] 陈烈强[1,2] 陈源[1,2] 蔡明招[2] 

机构地区：[1]传热强化与过程节能教育部重点实验室,广东广州510640 [2]华南理工大学化学与化工学院,广东广州510640

出　　处：《化工学报》2009年第1期216-222,共7页CIESC Journal

基　　金：教育部博士点基金项目(20060561008)~~

摘　　要：酚醛型线路板是国内废旧电子线路板的主要类型之一,因其较高的溴代阻燃剂浓度而难于常规回收处理。实现回收的关键在于脱溴,即将有机溴代物转化为无机溴化物。为此采用混合热解吸收技术,着重研究碳酸钙与酚醛型线路板混合热解的脱溴过程。对混合碳酸钙的酚醛型线路板热重实验结果的分析表明:碳酸钙的存在能有效吸收溴化氢并抑制其进一步转化为有机溴代物,从而促进脱溴。通过石英管式热解反应实验,采用莫尔法分析无机溴的相对含量,证实了热解时添加等质量的碳酸钙能吸收93.4%的无机溴并提高脱溴量1倍。对热解油进行GC/MS分析表明:添加碳酸钙后热解油中有机溴代物相对含量降低了25%,由此进一步表明碳酸钙能抑制有机溴代物的生成从而强化热解脱溴。Phenolic resin type waste PCB （wPCB） is one of the most important kinds of waste electrical and electronic equipment （WEEE） in China. It is usually hard to recycle for its high content of brominated flame retardants, so the key of recycling the wPCB is to debrominate, i.e., to convert the organic bromides into inorganic ones, e.g., hydrogen bromide （HBr） . Hence, pyrolytic debromination experiments were conducted to reveal the effect of blending calcium carbonate （CaCO3） with the wPCB in pyrolysis. The results of thermogravimetric analysis indicated that CaCO3 could absorb HBr to restrain them from reacting with organic molecules when the wPCB was blended with CaCO3 powders in pyrolysis. Further, a pyrolysis experiment blending the wPCB with CaCO3 in a quartz glass tube reactor was performed by means of silver nitrate titration to determine the content of inorganic bromides. The results showed that 93.4% inorganic bromides were trapped when the wPCB and CaCO3 blended in the same quantity, and two times of inorganic bromides than without belending CaCO3 were produced. Moreover, when the wPCB was pyrolyzed with CaCO3, the contents of organic bromides in the pyrolysates, measured by GC/MS, were 25% less than those when just wPCB was pyrolyzed. It proved that the CaCO3 helped to delarominate in the pyrolysis of the wPCB.

关 键 词：酚醛型线路板 回收 碳酸钙 热重分析 混合热解 脱溴 

分 类 号：X705[环境科学与工程—环境工程]