Institute of Multidisciplinary Research for Advanced Materials, Tohoku University 1,1 Katahira, 2-Chome, Aoba-ku, Sendai 980-8577, Japan.
J Hazard Mater. 2011 Mar 15;187(1-3):473-9. doi: 10.1016/j.jhazmat.2011.01.060. Epub 2011 Jan 19.
In the present work we investigate the vaporization of zinc or its compounds during thermal treatment of ZnO with tetrabromobisphenol A. Samples of 2g of ZnO:TBBPA (3.34:1) were isothermally heated in a laboratory-scale furnace at temperatures from 490 °C to 950 °C, and the solid, condensed and gaseous products formed were analyzed by X-ray diffraction analysis, electron probe microanalysis, inductively coupled plasma analysis, ion chromatography, and gas chromatography coupled with mass spectrometry. The results obtained indicate that the vaporization of ZnBr(2) formed strongly depends on heating time and temperature, yet is restrained by char, if formed with sufficient yield (above 15 wt%). Starting from 850 °C, this char commences carbothermic reduction of any remaining ZnO, which from then begins to evaporate as zinc metal vapor. Volatilization of zinc is completed at 950 °C. The presence of 5 vol.% of oxygen has no significant effect on the vaporization of formed ZnBr(2), the carbothermic reduction or the volatilization of metallic zinc. Strongly oxidizing conditions (20 vol.% of oxygen), however, boost the oxidation of char and thus the vaporization of ZnBr(2), but prevent carbothermic reduction of any un-reacted ZnO by depleting this char.
在本工作中，我们研究了在热解四溴双酚 A 处理 ZnO 过程中锌或其化合物的蒸发。将 2g 的 ZnO:TBBPA（3.34:1）样品在实验室规模的炉中以 490°C 至 950°C 的温度恒温加热，并通过 X 射线衍射分析、电子探针微分析、电感耦合等离子体分析、离子色谱和气相色谱与质谱联用分析所形成的固体、冷凝和气相产物。结果表明，ZnBr(2)的蒸发强烈依赖于加热时间和温度，但如果以足够的产率（高于 15wt%）形成，则受到炭的限制。从 850°C 开始，这种炭开始对任何剩余的 ZnO 进行碳热还原，此后 ZnO 开始作为锌金属蒸汽蒸发。在 950°C 时，锌的挥发完成。存在 5vol.%的氧气对形成的 ZnBr(2)的蒸发、碳热还原或金属锌的挥发没有显著影响。然而，强烈的氧化条件（20vol.%的氧气）会促进炭的氧化，从而促进 ZnBr(2)的蒸发，但通过消耗这种炭，阻止任何未反应的 ZnO 的碳热还原。
