UTILIZATION OF TIGER NUT (CYPERUS ESCULENTUS) CHAFF ASH AS A FLUX IN CERAMIC GLAZE
Aigbudume T.E, Opoku E.V, Alkali C.V.This study explores the valorization of tiger nut (Cyperus esculentus) chaff ash (TNCA), a fibrous agro-waste by-product, as a sustainable flux material in high-fire ceramic glaze formulations. The research addresses the environmental burden of agricultural waste and the reliance on imported ceramic raw materials in Nigeria. TNCA was produced by calcining dried tiger nut chaff at 800°C and analyzed using X-ray fluorescence (XRF) to determine its chemical composition. The results revealed an unusually high flux content dominated by CaO (24.54%), P₂O₅ (17.73%), Fe₂O₃ (12.54%), and volatile SO₃ (19.83%), with critically low glass-forming oxides: SiO₂ (5.61%) and Al₂O₃ (1.82%). This profile confirmed TNCA’s potential as a powerful flux but highlighted its unsuitability for standalone use. Twenty-one glaze formulations were developed using line and triaxial blends with potassium, feldspar and ball clay. Glazes were applied to stoneware tiles and fired at 1260°C. Optimal compositions (40% TNCA, 40% feldspar, 20% ball clay) yielded stable, glossy, impermeable surfaces with warm brown tones. Seger formula analysis confirmed their durability and suitability for high-fire applications. The study demonstrates TNCA’s viability as a cost-effective, locally sourced flux, contributing to sustainable ceramics and circular economy goals.