Design and development of porcelain tiles using local post-consumer wastes: microstructural and mechanical characterization

Mixtures used for the production of porcelain tiles consist of inorganic raw materials such as illitic and kaolinitic clays, tempering materials such as sands, and feldspars as fluxing agents. Illitic and kaolinitic clays are used as plasticizers in the mixture, while feldspars are fluxing agents which create an abundant melted phase with a proper viscosity during the firing process of the tiles that results in a compact vitreous structure of the final product. Sands represent the skeleton of the porcelain tile and at the same time limit the shrinkage during firing. During the preparation of this thesis, two innovative mixtures have been formulated, in which the introduction of local industrial and urban post-consumer wastes substituting clays and feldspars lead to advantages regarding energy consumption and improved characteristics of the final product. The samples obtained in each phase of the laboratory production process were tested to verify if the innovative mixtures are suitable for an industrial technological transfer. The results obtained show a stable behavior of the mixtures in terms of shrinkage during the firing process, while the optimal firing temperature has been reduced significantly leading to a considerable energy saving during this phase of the production.