Recycling of incinerator fly ash for the manufacture of artificial aggregate by cementitious granulation

The waste employed in this work comes from an incineration plant equipped with rotary and stoker furnaces, in which municipal, hospital and industrial wastes are treated. Ash from waste incineration plant is classified as hazardous and cannot be utilized or even landfilled without prior treatment. This paper reports the results of an extensive investigation on stabilization/solidification of the above ash by a granulation process in which cement, lime and coal fly ash were used as binder components. Granulation was carried out with several mixes in which the ash content was up to 70% and, in most cases, two-step granulation was performed with pure binder being used in the second one. In some cases, the granules obtained in this way are suited for matter recovery in the field of artificial aggregates for road construction and concrete manufacture.