水泥窑处置垃圾焚烧飞灰中试研究

Pilot test of MSWI fly ash treatment with cement kiln

对垃圾焚烧飞灰处置量为100t/d的中试线的水洗单元、焚烧单元及水洗液处理单元的工艺参数进行了探索。水洗单元的最佳工艺为:水灰比3∶1,1次顺流+2次逆流漂洗的方式。添加飞灰后,窑尾烟气中的污染物排放均有增加,以酸性气体和二恶英类增加最多,但均满足GB4915—2004要求。添加飞灰后烧制的水泥熟料,其标准稠度用水量及氯含量有所升高,而28d强度及凝结时间均有所降低,但差异不显著。钙及重金属是水洗液处理主要的去除对象。经过通CO2、投加Na2CO3、Na2S和FeSO4的处理,基本达到了去除钙及重金属的目的。

A rotary kiln of 100t/d capacity used for MSWI fly ash treatment pilot test was built to explore the process parameters of water washing unit, incineration unit and lavage fluid water treatment. The optimum parameter was that the ratio of liquid to solid should be 3：1 and once concurrent plus twice counterflow washing system. The pollutant in flue gas emission were increased with the addition of fly ash, and the acidic gas and dioxin increased most, but all of them meet the requirements of GB4915-2004. The water requirement of normal consistency and chlorine content of clinker increased when adding fly ash, and the 28d compressive strength, 28d flexural strength and initial setting and final setting time were reduced slightly. Ca and heavy metal was main target to be removed in lavage fluid water treatment. By treating with CO2, Na2CO3, Na2S and FeSO4, Ca and heavy metal could he removed in principle.