Compound Stabilization Of MSW Incineration Fly Ash With Copperas And Cement

The MSWI(municipal solid waste incineration) fly ash has been classfied as the hazardous waste because of its heavy metals content, soluble salts and dioxin content. Safety landfill after solidification with cement is the most popular disposal way for MSWI fly ashes. But this technology has some problems such as volume increase and longtern heavy metal leaching is unpredictive etc. In order to solve those problems, in this research, a compound stabilization with copperas and cement has been proposed studied.In the research process, fly ash samples were taken from an ordinarily operating incineration plant firstly stabilized with copperas and than solidified by cement. In the chemical stabilization process, the influence reaction conditions such as the kind of process water and removal of slats from treated fly ash samples have been investigated, while ing the solidification process, the drying condition of the fly ash is also considered. Furthermore, leaching tests and the compressive strength of the solidified blocks by different mass ratio of ash/cement were studied and compared. These blocks were carried to check the stabilization effect of heavy metals a compressive strength were measured to compare the strength of the solidification products.The experimental results showed that the process water has neglected influence on the chemical stabilization process; better performance on leaching heavy metal has been gained when the fly ash was compound stabilizaed without drying process.The compound stabilization is better than single cement solidification when the mass ratio of ash/cement is 1:1, the leaching level of Pb, Cr which the ashes treated by compound stabilization, is only 40ppb, 110ppb, while these numbers of the ash which treated by cement solidification is 67ppb, 449ppb. The result also showed that the compressive strength of the compound stabilized products increased from 0.83MPa to 76MPa when the proportion of ashes/cement changed from 90/10 to 10/90 and then, at most proportions, the compound stabilized products have more...