Bottom and fly ashes: inertization and reuse

Roberto Vinai (University of Exeter)

Ashes from combustion/incineration processes account for a huge volume of man-made materials that are both a threat as well as an opportunity for our present and future societies. This contribution will explore the most common by-products from combustion and incineration operations, recalling main chemical compositions and physical properties, summarising the legal framework for the production and utilisation of ashes, and underlying the main environmental or technical issues related to their use.

The discussion will then cover main methods for inertization of hazardous materials, focussing on techniques for the entrapment of heavy metals and for the abatement of organic pollutants, and will give an overview of other issues such as radioactivity of combustion ashes.

Common routes for the reuse and recycling of ashes, as well as for the recovery of valuable elements will then be described, with a special emphasis on building material applications.

The intervention will be closed by providing some conclusions and perspectives in the utilisation of combustion and incineration ashes.