The Effect of Partial Substitution of Feldspar with Palm Bunch Ash on the Mechanical and Electrical Properties of Porcelain Insulator Production

Abstract

The production of electrical porcelain insulators in Nigeria relies heavily on imported materials like feldspar which increase the cost of production and purchasing price of electrical porcelain insulators. This study investigated the partial substitution of feldspar with Palm Bunch Ash (PBA), a silica-rich by-product of the palm oil industry to enhance sustainability and cost-effectiveness. Using local raw materials (kaolin, quartz, ball clay) and PBA at substitution ratios of 0%, 5%, 10%, 15%, and 20%, samples were prepared, fired at 900°C, and glazed at 1250°C. Mechanical properties (moisture content, plasticity, shrinkage, water absorption, porosity, density) and electrical properties (resistivity, dielectric strength) were evaluated. The results showed that 5% PBA substitution achieved optimal performance, with a resistivity of 2.92 × 10¹⁴ Ω-m and dielectric strength of 9.0 kV/mm, comparable to conventional insulators, while reducing raw material costs by 20%. Higher PBA levels increased porosity, compromising insulation efficiency. This approach leverages local waste to address resource constraints, aligning with circular economy principles and supporting Nigeria’s power sector. This is the first systematic evaluation of PBA as a feldspar substitute in Nigerian porcelain insulators, validating its role in circular economy-driven ceramic production.