UTILIZATION OF SAHEL GRANITE DUST FROM GUDUM HAUSAWA IN BAUCHI STATE AS A GLASS FORMER IN THE FORMULATION OF STONEWARE GLAZES

This study investigates the suitability of Gudum Hausawa Sahel granite dust, a quarrying by-product from Bauchi, as a substitute for commercial silica in stoneware glaze formulation. The chemical and mineralogical properties of the granite dust were analysed using X-ray Fluorescence (XRF) and X-ray Diffraction (XRD) respectively. XRF results revealed high silica content (59.20% SiO₂) and substantial alumina (20.30% Al₂O₃), while XRD analysis indicated that the material is predominantly composed of quartz (~69wt.%) with significant feldspar phases (~28 wt.%), providing inherent fluxing oxides. These characteristics confirm that granite dust can function as both a glass former and a source of intrinsic fluxing agents. Glaze formulations were developed using the triaxial blend method, incorporating granite dust at varying proportions (0-40%) and compared with conventional silica-based control glazes. The glazes were applied to bisque-fired stoneware tiles and fired in an electric kiln under oxidizing conditions at temperatures between 1200 °C and 1250 °C. Post-firing evaluation showed that optimal compositions containing 20-40% granite dust exhibited good melting behaviour, producing smooth, glossy, and well-vitrified surfaces comparable in fusion, adhesion, and aesthetic quality to conventional glazes. The presence of iron oxide contributed to natural brown to dark-brown colouration without the need for additional colorants. The results demonstrate that granite dust is a technically viable and sustainable alternative to commercial silica in stoneware glaze production. Its utilization offers economic advantages through cost reduction and supports environmental sustainability by promoting waste valorization and reducing reliance on imported raw materials. This study highlights the potential of granite dust for industrial application in ceramic glaze formulation.