Bottom ash treatment at the site of producing plant for reutilization.

Bottom ashes are the solid residues remaining in the furnace after solid waste incineration, mainly consisting of unburnable materials. They are classified as industrial non-hazardous waste from the European Waste Catalogue. The final disposal or reuse of BA is strictly linked to the potential release of constituent contaminants into the environment. In this study we considered the possibility of improving the quality of bottom ashes, by accelerated carbonation, in order to make them suitable for disposal in landfills for inert waste or for the reuse in construction works. In particular, we evaluated the possibility of using the flue gases from waste incineration plant as an alternative source of carbon dioxide for use in the controlled accelerated carbonation of the BA produced by the incineration plant itself. The process was preliminarily investigated at laboratory scale and then evaluated from an economic point of view, estimating the specific cost for the treatment, which ranged from 19 to 22 Euro per t of processed BA.