Assessment of clay mineral deposits from Nkemkol in Ogoja local government area of cross river state for application as raw materials in ceramic industries

This research evaluated the potential of clay deposits from Nkemkol, Ogoja in Cross River State, Nigeria as local raw materials for industrial use. Four samples were gathered from various sites in the area. The clays were analyzed using X-ray fluorescence, X-ray and physical property tests to determine their geochemical composition, mineral content, and key characteristics. The analysis revealed high levels of silica (56.41%) and alumina (32.82%), which are typical of aluminosilicate clays. Iron oxide content was moderately high at 3.34% Fe₂O₃. The predominant clay minerals identified were kaolinite (18.9-37.0%) and illite (0.5-4.15%), along with non-clay minerals such as quartz, feldspars, and metal oxides. The clays exhibited significant plasticity (average plasticity index of 26.61%), facilitating easy molding and shaping. The average porosity was 21.33%, suitable for refractory applications. Firing shrinkage ranged from 6.5% to 19.2%, with density measurements between 1.54 and 1.76 g/cm³, both within acceptable limits. Post-firing strength met the minimum standard of 15 N/mm², with an estimated refractoriness of 1680.22°C. Overall, the Nkemkol clays possess favorable chemical, mineralogical, and physical properties for use in refractories and structural ceramics, pending some processing modifications. Utilizing these local deposits could enhance import substitution, foster rural industrialization, and support sustainable development in Nigeria. Further pilot testing is recommended to refine formulations and processes for specific ceramic products, along with a comprehensive national survey of clay deposits. The clays are deemed suitable for applications such as refractory bricks, ceramic tableware, architectural ceramics, wall tiles, and pottery items.