Bottom ashes recycling in the ceramic tiles production: technical and environmental aspects

Sustainable use of natural resources and recycling/reuse of wastes are two of most current upcoming environmental problems, and they play an important role in the circular economy, as recycling of waste can give an important contribution to the reduction of natural resources. Ceramic tiles production is one of the industrial activities involved in using natural resources like clays and sands. On the other hand, in Italy, sanitary landfills are, nowadays, the main place, where bottom ashes are finally treated. This paper presents and discusses technical and environmental aspects referred to an industrial experiment, in Central Italy, where they are going to produce ceramic tiles, using bottom ashes in the mixture with feldspatic sands and clays. As a matter of facts, bottom ashes, produced by the incineration of urban solid wastes, coming from the selected collection of urban solid wastes, are made of oxides, similar ones making some silicate minerals, which are part of sands and clays, involved in ceramic tiles production. To make sure as the final users as the Government Institutions that the final product will have the expected technical and environmental properties, authors set up a specific protocol, which has been approved by the Government Institution which would give the specific authorization for the industrial regular production of these ceramic tiles. The aim of this paper is to describe the most important tests, included in the abovementioned protocol, in relationship with the technical and environmental aspects they have to be faced, before these ceramic tiles could be commonly sold.