Development of Transparent Glaze Using Local Raw Materials

The development of transparent ceramic glazes using locally sourced raw materials offers a sustainable and cost-effective approach to enhancing the aesthetic and functional properties of ceramic wares. This study focuses on formulating and evaluating transparent glazes derived from indigenous Nigerian materials, including silica, lead sulphide, kaolin, and feldspar and quartz. Additives such as bentonite and sodium silicate were incorporated to improve plasticity and fluidity, respectively. The raw materials underwent a series of processing steps: crushing, milling, and batch formulation to create four distinct glaze compositions (Batches A, B, C, and D) with varying ratios of the materials. Each batch was mixed with water to form a uniform suspension, applied to bisque-fired ceramic wares via dipping, and subsequently fired at approximately 1108°C. Analysis of the glaze compositions revealed that silica content ranged from 10% in Batch C to 70% in Batch D, serving as the primary glass-forming agent contributing to transparency and durability. Kaolin varied between 10% (Batch D) and 30% (Batch C), acting as a suspending agent and influencing viscosity and adhesion. Lead sulphide, a potent flux, was present from 20% in Batch D to 60% in Batch C, effectively lowering the melting point and enhancing the glaze's fluidity and glossiness. The study observed that higher silica concentrations, as in Batch D, resulted in glazes with increased transparency and surface smoothness, while elevated lead sulphide levels, as in Batch C, produced glazes with enhanced fluidity and a glossy finish. However, excessive lead content may pose health and environmental concerns, necessitating careful optimization. These findings underscore the potential of utilizing local Nigerian raw materials in developing transparent ceramic glazes, promoting sustainability, reducing reliance on imported materials, and fostering economic growth within the local ceramics industry.