Carbonatic clays for the production of porous ceramic tiles by fast single firing

Plio-Pleistocene clayey marls are widespread in Italy and they have been widely used in the traditional Italian ceramic production. So, the present study was undertaken to verify the possible application of the same raw materials in the production of the modem porous tiles obtained through fast single firing ("monoporosa"). For this purpose, thirteen clay samples were collected in a wide area near Faenza (northern Italy). The analyses demonstrated that they are quite uniform from the chemical, mineralogical, and granulometric point of view. Technological tests at both laboratory and industrial level pointed out that the clayey marls in hand are suitable to be utilized in an up-to-date porous tile production. The optimum content in the starting body is around 25 %.