Characterization of Kaolin from Three Sites in Northern Nigeria as Alternative Raw Material for The Production of Laboratory Evaporating Dish

Abstract

This study focused on the characterization of kaolin obtained from three deposits in Nigeria—Kuba (Plateau State), Alkaleri (Bauchi State), and Itobe (Kogi State) to evaluate their suitability as locally sourced raw materials for the production of laboratory evaporating dish. The growing demand for indigenous ceramic raw materials has increased interest in kaolin because of its abundance and versatility in ceramic applications. The kaolin samples were subjected to mineralogical, chemical, thermal, and physical characterization using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy coupled with energy dispersive Xray spectroscopy (SEM/EDX), thermogravimetric analysis (TGA), differential thermal analysis (DTA), Atterberg limit tests, and hydrometer analysis. The results were compared with established standards for stoneware and laboratory ceramics. The analyses revealed that the samples contained significant amounts of kaolinite with minor impurities, suitable chemical compositions, and favorable firing characteristics. XRF results showed SiO₂ contents ranging from 51.68–65.73% and Al₂O₃ contents from 24.39–39.70%. Fe₂O₃ contents ranged between 1.75–6.90%, indicating acceptable purity for ceramic applications. The beneficiated Kuba kaolin recorded the highest SiO₂ content (65.73%), while Alkaleri exhibited the lowest (51.68%). The Atterberg limit test showed plasticity indices of 42.4%, 40.7%, and 34.1% for Kuba, Alkaleri, and Itobe respectively, indicating good moulding and shaping characteristics. Hydrometer analysis confirmed the dominance of fine clay fractions, suggesting good workability and sintering behavior. TGA and DTA results revealed characteristic kaolinite dehydroxylation within 450–650°C, confirming thermal stability suitable for ceramic firing. The study demonstrates that the investigated kaolin deposits possess the mineralogical, chemical, thermal, and physical properties required for the production of durable and chemically resistant laboratory evaporating dish. The findings contribute to the characterization and utilization of indigenous raw materials and support the advancement of local ceramic technology in Nigeria.