Characteristics of municipal solid waste incineration fly ash with cement solidification treatment

Abstract Cement solidification technology can effectively reduce environmental pollution caused by municipal solid waste incineration (MSWI) fly ash. The present study aimed at investigating the impacts of three factors on the heavy metal leaching content, and the curing time on the strength of mortar specimens blended with MSWI fly ash. The factors are the quantity of cement, the PH value of leaching liquid and the vibrating leaching time. And the fly ash used in experiments is sampled from Harbin MSWI power plant. The results demonstrated that the leaching concentration of heavy metal of MSWI fly ash reduced significantly after being blended with cement, especially for Pb and Cd. As the PH value of the leaching liquid increased, the heavy metal leaching concentration quickly cut down to a very low value. The heavy metal leaching concentration significantly increased with leaching vibrating time in range of 16 h or 32 h. But conversely, both flexural strength and compressive strength of mortar specimens obviously dropped and the curing time of mortar specimens was delayed due to the addition of MSWI fly ash. Fortunately, the strength of mortar exceeds strength requirement of non-main building and base structure concrete and it can be recycled as base structure material.