【摘要】 研究了添加剂(粘土和粉煤灰)、水洗预处理对焚烧飞灰烧结过程重金属(Cd、Cu、Zn、Pb、Cr、Ni)迁移特性的影响.水洗时间为8、16、24 h.烧结实验条件为成型压力3 kN,烧结温度1 100℃,烧结时间4 h.结果表明,在飞灰中粘土添加比例增加到70%时,重金属Cd的固化率从16.96%升高到28.42%,Pb的固化率从10.58%升高到37.02%,Cu的固化率从46.38%上升到55.14%,Zn的固化率从42.14%上升到64.47%,Ni和Cr的固化率总体上呈现下降的趋势.总体上添加粘土对焚烧飞灰烧结过程中重金属的固定效果有限.当粉煤灰在烧结前样品中的比例增加时,Cd的固化率从16.96%下降到4.67%,Cu的固化率从46.86%上升到81.43%.粉煤灰的加入对于Zn和Pb的影响不大,对于Ni和Cr的影响规律也不明显.水洗预处理可以把Cd、Cu和Pb的固化率提高到80%以上.焚烧飞灰烧结体TCLP浸出测试表明,添加粘土和粉煤灰以及水洗预处理后,焚烧飞灰烧结试体的重金属浸出浓度普遍较低.更多还原

【Abstract】 An experimental work was carried out to investigate the effect of additives(clay and coal fly ash) and washing-pretreatment on the stabilization of critical heavy metals(Cd,Cu,Zn,Pb,Cr,Ni) during a sintering process of municipal solid waste incinerator(MSWI) fly ash.The proportions of the three constituents were varied to adjust the mixture compositions.The washing time were 8 h,16 h and 24 h.The material was compacted in cylindrical specimens at 3 kN and treated at(1?100℃) for 4 h.When the clay content was increased to 70%,the stabilized ratio was increased from 16.96% to 28.42% for Cd,from 10.58% to 37.02% for Pb,from 46.38% to 55.14% for Cu,from 42.14% to 64.47% for Zn,but the stabilized ratio of Ni and Cr was decreased.When coal fly ash was increased in the MSWI fly ash,the stabilized ratio was decreased from 16.96% to 4.67% for Cd,increased from 46.86% to 81.43% for Cu,but the addition of coal fly ash did not increased the stabilized ratio of Zn,Pb,Ni and Cr.Washing pre-treatment increased the stabilized ratio of Cd,Cu and Pb significantly.The leaching behavior of the heavy metals in the sintered products was studied by the toxicity characteristic leaching procedure(TCLP),the results showed that the leaching concentration of the six heavy metals were very low.更多还原