Sa’a quartzite (Center Region, Cameroon) : Its use to process natural stone tiles and experimental incorporation of its fine waste in producing ceramic tiles

This work presents the physical and mechanical properties of processed quartzite natural stone tiles and the manufacture of ceramic tiles by combining clay material with feldspar and a partial replacement of clay material with fine waste from the cutting of natural stone tiles. The raw materials (clay materials, fine quartzite waste, and feldspar) used for the experimental processing of the ceramic tiles were first characterized using Atteberg limits, grain size distribution, and/or specific gravity. Physical tests (color, sound, mass loss, linear shrinkage, apparente density, water absorption, and porosity) and mechanical tests (flexural and compression strength) were carried on formulated prototypes before processing the ceramic tiles final products. The apparent density (2.53–2.86 g/cm ³ ), water absorption (0.66 to 1.32%); porosity (1.73 to 3.37%), compressive strength (96 to 106 Mpa), flexural strength (7.2 to 10.8 MPa), and resistance to abrasion (22.76 to 53.51 cm ² /g) for processed natural stone tiles are mainly within the standard values for natural stone tiles. The characteristics of those natural stone tiles make some suitable for flooring and others for covering inner walls. The plasticity indice for the two used clay materials (Nkolbisson clay : 18.63% and Bamali clay : 25.95%) places them within the range limit of 15–30% of good plastic soil. The particle-size distribution and specific gravity results led to their classification as fine-grained soil; with clay material from Bamali (silty-sandy-clay) being much finer than that of Nkolbisson (sandy clay). The specific gravity of fine quartzite waste (2.70-2.714) and that of feldspar (2.71) are within the range limit of those used to process ceramic tiles. The color of the formulaled ceramic tile prototypes is pale orange (predominant), pale reddish, or light yellow. The sound is metallic (predominant), dull, or strong metallic. The mean values of mass loss (3.40–7.37%), linear shrinkage (0.44–1.93%), apparent density (1.48–1.88 g/cm ³ ), water absorption (13.76–32.14%), and porosity (24.82–47.38%), flexural strength (1.58–3.98 MPa), and compression strength (4.0-10.88 MPa), mainly show a decrease in their values with the increase in proportion of fine quartzite. Formulations in group 3 (processed by combining Bamali clay material + feldspar + fine quartzite waste) with their interisting results, were used to manufacture the ceramic tiles final product.