基于二次铝灰的地聚反应稳固化垃圾飞灰

基于工业生产铝过程中回收的二次铝灰（SAD）的地质聚合反应，提出了一种稳固化城市生活垃圾焚烧飞灰（MSWIFA）的新方法，分析硅铝物质的量之比对飞灰中重金属浸出浓度及地聚物固化体力学性能的影响规律.结果表明，当硅铝物质的量之比小于2.5时，二次铝灰-SiO₂基固化体与偏高岭土-SiO₂基固化体中的重金属浸出浓度均随着硅铝物质的量之比的增加而逐渐降低，2种固化体的抗压强度随着硅铝物质的量之比的增加而增加；硅铝物质的量之比达到2.5时，重金属的浸出浓度与固化体的抗压强度均趋于稳定.XRD分析结果显示，偏高岭土-SiO₂基固化体中聚合物的种类与数量均略高于二次铝灰-SiO₂基固化体.但从重金属的浸出浓度与固化体的抗压强度来看，2类固化体对飞灰中重金属的稳固化效果的差别很小，二次铝灰加上部分硅基材料可以作为偏高岭土的替代品，用于稳固化飞灰重金属的地质聚合反应中.二次铝灰-SiO₂基固化体的抗压强度达到13.65MPa，具备一定的力学性能，可用于部分特定的建筑材料.

Experimental study on the stabilization/solidification of MSWIFA by geopolymerization based on secondary aluminum dross

A new method for stabilization/solidification of municipal solid waste incineration fly ash (MSWIFA) by geopolymerization based on secondary aluminum dross (SAD) that recycled from the production of aluminum is proposed. The effect of Si/Al molar ratio on the stabilization/solidification of solidified bodies was investigated in the study. When the molar ratio of Si/Al was less than 2.5, the leaching concentration of heavy metals such as Cr, Cd, Pb, Zn and Cu in SAD-SiO₂-based and metakaolin-SiO₂-based solidified bodies decreased significantly and the compressive strength of the cured solidified bodies increased obviously with the enhancement of the Si/Al molar ratio. When the Si/Al molar ratio exceeded 2.5, the leaching concentration of heavy metals and the compressive strength of both the solidified bodies tended to be stable. The result of XRD analysis suggested that the categories and contents of polymers in metakaolin-SiO₂-based solidified bodies were slightly higher than SAD-SiO₂-based solidified bodies. However, the disparity between these two sorts of solidified bodies was tiny, which proved that SAD with silica-based materials could be potential substitutes for metakaolin in order to improve the Si/Al molar ratio and thereby ameliorate the consequent of stabilization and solidification. Furthermore, the solidified wastes could be applied to be certain construction materials because the compressive strength of SAD-SiO₂-based solidified bodies could be increased to be 13.65MPa.