Ceramic facing tiles (EN 159) obtained from dry-ground Italian raw materials. Part I.

Optimization of dry grinding of paste, contg. exclusively Italian raw materials, for use in prodn. of porous ceramic facing tiles (EN 159) was studied using a rolling vertical mill (Pfeiffer MPS 141A); the results obtained demonstrate that it is possible, using cycles of single-firing (39 min at max. temp 1080 C) and rapid double-firing (28 min firing, 7 min drying, inertization at max. temp 1065 C, and glazing 45 min at max. temp. 1055 C), to obtain products with the functional properties required by the strict European std. Baiso 160 clay is predominantly illite and chlorite with high contents of Ca and Mg oxides; Alloero Refrattoria is predominantly illite and chlorite with high content of free qt and trace carbonates.