| 焚烧飞灰预处理工艺及其无机氯盐的行为研究 |
| 摘要点击 4122 全文点击 1686 投稿时间：2012-09-03 修订日期：2012-11-18 |
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| 中文关键词 焚烧飞灰 无机氯盐 水洗 烧结 X射线吸收近边精细结构 |
| 英文关键词 MSWI fly ash chlorides washing calcination X-ray absorption near edge structure (XANES) |
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| 中文摘要 |
| 研究表明WCCB(水洗+烧结)预处理工艺能更高效更节能地去除飞灰中的氯化物,以利于其作为水泥原料的使用. 水洗工艺条件为两次水洗、水固比均为3∶1,搅拌速度均为150 r·min-1,第一次水洗时间5 min,第二次水洗时间10 min; 利用原焚烧炉进行烧结处理,温度为1000℃,10%氧气含量,停留时间1 h. 本研究尝试了3种焚烧飞灰:节煤器出来的飞灰、石灰干法中和酸性气体后布袋收集的飞灰、NaHCO3中和酸性气体后布袋收集的飞灰. 经该工艺处理后,焚烧飞灰残渣量减少20%以上,氯减少94%以上,尤以NaHCO3中和得到的飞灰削减量为最,分别达到了72.1%和99.8%. 采用同步辐射的X射线吸收近边精细结构(X-ray absorption near edge structure, XANES)和普通X射线衍射(X-ray Diffraction, XRD)相结合的方法研究分析无机氯盐在工艺过程中的行为,发现焚烧飞灰中主要的氯盐主要有NaCl、KCl和CaCl2. 焚烧炉烟气净化系统的酸中和剂会影响无机氯盐的生成. 焚烧飞灰中难溶性无机氯盐的结构与Friedel's盐相似,并且与CaCl2有关系. |
| 英文摘要 |
| The introduced pretreatment technology, WCCB (Washing+Calcination), was effective to reduce chlorides in fly ash by consuming relatively low energy for recycling fly ash as the raw material for cement industry. The washing conditions are: twice-washing, liquid/solid=3, mixing speed=150 r·min-1, 1st mixing time=5 min, and 2nd mixing time=10 min. The original incinerator was used for the calcination process, 1000℃, 10% O2 and dwelling time of 1 hour were adopted. By adopting X-ray absorption near edge structure and X-ray diffraction, the behavior of chlorides was explained and NaCl, KCl and CaCl2 are the main form of chlorides existing in fly ash. The reagent used in the air pollution control system to neutralize the acid component in the discharged gas surely acted a very important role in the formation of chlorides. The insoluble chlorides in fly ash had a very similar structure as that of Friedel's salt, which was related with CaCl2. |
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