| 焚烧飞灰高温过程中重金属的挥发及其氯转化特征 |
| 摘要点击 2638 全文点击 1397 投稿时间：2011-11-20 修订日期：2012-03-29 |
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| 中文关键词 飞灰 污泥焚烧 重金属 挥发率 氯化剂 |
| 英文关键词 fly ash sewage sludge incineration heavy metal volatilization chlorides |
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| 中文摘要 |
| 研究了垃圾与污泥掺烧后的焚烧飞灰在900℃、1000℃高温处置过程中重金属(Cu、Zn、Pb、Cd)随不同停留时间的挥发特性,并研究了添加剂氯化物(CaCl2、MgCl2、NaCl、FeCl3、AlCl3)对重金属转化与挥发特性的影响. 结果表明,没有添加氯化剂情况下,污泥焚烧飞灰中不同重金属的挥发特性有较大的差别,其中Pb的挥发率超过80%,而Cu的挥发率<30%,重金属的挥发性大小依次为:Pb>Cd>Zn>Cu. 热处置过程中重金属的挥发率受温度的影响较大,而停留时间的延长对重金属挥发促进效果较小,并且易挥发元素Pb和Cd表现尤为明显. 飞灰中添加氯化剂后,重金属的挥发性有显著的改变,并且难挥发元素Cu和Zn的挥发性增加较Pb和Cd显著. 随着Cl含量的增加,重金属挥发率有增加的趋势,但不同种类的氯化物对重金属氯转化差异较大,其中NaCl对重金属Cd、Zn和Cu挥发特性的促进效果小于其它氯化剂. 研究结果为飞灰最大限度无害化处理及资源化回收利用提供理论依据. |
| 英文摘要 |
| The volatilization of heavy metals Pb, Cd, Cu and Zn were studied at 900℃ and 1000℃ with different residence time, meanwhile the influence of chlorination agents CaCl2,MgCl2,NaCl,FeCl3 and AlCl3 on heavy metals volatilization was studied. The results showed that the volatilization of heavy metals had great differences with the volatilization rate followed the order Pb>Cd>Zn>Cu, in which the volatilization rate of Pb was more than 80% and that of Cu was less than 30%. In the thermal disposal process, the volatilization rate influenced by temperature was greater than that by the residence time, and the volatile elements Pb and Cd were particularly evident in the volatilization. After adding chlorides in fly ash, the volatilization of heavy metals changed significantly, and the volatilization rate of the low volatile elements Cu and Zn increased significantly compared with Pb and Cd. With the content of chloride increasing, the volatilization rate of heavy metals increased, but different types of chloride compounds on heavy metal transformation were quite different, in which the promotion effect of NaCl on heavy metals Cd, Zn and Cu was less than that of other chlorinating agents. The results can provide strategies for the harmless disposal and maximize resource utilization and recycling of fly ash. |
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