Accelerated carbonation of municipal solid waste incineration fly ash

Because of the high Ca and amphoteric heavy metals content of the municipal solid waste incineration (MSWI) fly ash, accelerated carbonation at high liquid to solid ratio of 10:1 was investigated to improve its physical and chemistry properties. Carbonation and heavy metals (Pb, Cu, Zn, Cd, Ni, Cr) mobility were studied by applying mineral analysis, morphology analysis, porosity analysis and leaching assays. XRD analysis showed the disappearance of the CaClOH peak and the appearance of CaCO₃ in the accelerated carbonated fly ash were showed. Treatment through carbonation reduced the pH of the fly ash from 12.4 to 7, and reduced the leaching concentration of Pb Cu, Zn and Ni by 99.7%, 93.9%, 90.6% and 27.8%, respectively. However, the leaching concentration of Cr increased 29.7%.