不同氧化物对废线路板真空热解过程脱溴效果的影响

摘要

Debromination tests of epoxy resin powders from waste printed circuit boards (WPCB) were carried out at 500℃ by adding three types of oxides ( Fe-based, Ca-based and Al-based). The effects of the oxide additives on to the distribution of organic and inorganic bromine in solid, liquid and gas phases of the pyrolysis products were studied by ion chromatography and oxygen bomb combustion methods. The results indicate that the Fe-based and Ca-based oxides can significantly reduce bromine content in the pyrolysis liquids, with most bromine distributed in the solid phase. Fe3O4 and CaCO3 display better debromination effect than other Fe and Ca oxides. The distribution of bromine in the pyrolysis oil reduces from 72.10%without any oxide to 8.91%and 7.69%with Fe3O4 and CaCO3. The efficiency of organic-inorganic bromine conversion increases from 46.42% to 82.25% and 92.13%, respectively. As a result, 78.74% and 90.84% of bromine exists in pyrolysis residues is inorganic bromine. Meanwhile, the Al-based oxides can obviously increase water content of the pyrolysis liquid. In addition, most bromine in the WPCB including organic bromine in the oil phase and inorganic bromine in the water phases is transferred into the pyrolysis liquid. The types and amount of bromine compounds in the oil phase were analyzed by GC/MS. In conclusion, Fe-based and Ca-based oxides are better for debromination applications comparing to Al-based oxides.%在500℃下，进行了废线路板环氧树脂粉末与Fe系、Ca系和Al系三类氧化物的真空共热解脱溴试验。通过离子色谱分析和氧弹燃烧法，研究了不同氧化物对固、液、气三相热解产物中有机溴和无机溴分布的影响。试验结果表明，Fe系和Ca系氧化物能显著降低热解液体中的溴含量，大部分的溴残留在固相中。其中以Fe3O4和CaCO3的脱溴效果最好，热解液体中的溴分布率从没有添加时的72.10%分别降到8.91%和7.69%，分别有78.74%和90.84%的溴以无机溴的形态残留在热解渣中，有机溴转化为无机溴的效率从没有添加时的46.42%分别提高到82.25%和92.13%。Al 系氧化物能明显增加热解液体中的水分含量，原料中的溴绝大部分转移到液相中，包括油相中的有机溴和水相中的无机溴。Fe系和Ca系氧化物的脱溴效果优于Al系氧化物。用GC/MS分析测定了油相中含溴化合物的种类和相对含量。