Physical and mechanical properties of a tile produced with Burkina Faso clay

Abstract

This study proposes an approach for manufacturing wall tiles from raw clayey material from Burkina Faso for use in the local ceramic industry. To this end, a clay sampled of Kodeni (KOD), primarily composed of kaolinite (62 wt.%), quartz (31 wt.%), and goethite (3 wt.%), with contents of 60.79 wt.% SiO₂ and 24.36 wt.% Al₂O₃ was used for wall tile manufacture. All the results of the physico-mechanical tests on the tiles developed at temperatures of 1150°C, 1200°C, and 1250°C show that these tiles meet the standards for mechanical strength of water absorption and thermal conductivity for ceramic applications. The formulation of the samples enriched with feldspar (25 wt.%) and fired achieved maximum flexural strengths of 22.58 MPa at 1250°C for the formulation containing no feldspar (F0) and 25.69 MPa at 1200°C for the formulation containing 25 wt.% feldspar (F1), confirming the densifying effect of feldspar at moderate temperatures. In addition, the water absorption and porosity of the tiles decreased progressively with increasing temperature, ensuring properties in line with ISO 13006 for wall use. The tiles also exhibited low thermal conductivity (≤ 1 W/(m.K)), limited and controllable linear shrinkage, and reduced deformation. These results suggest that KOD clay, amended with 25 wt.% feldspar at 1200°C temperature, is suitable for manufacturing wall tiles. Scanning electron microscopy analysis is planned to explore the evolution of the microstructure and viscous phase as a function of firing temperature to understand better the sintering processes and the interactions between the different stages.