Composition, Geotechnical Characteristics and the Potential for Industrial Use of Some Clay Bodies in Obudu and its Environs, Southeastern Nigeria

Samples of clay deposits in Obudu and its environs, southeastern Nigeria were evaluated to establish their potential for industrial use. Geochemical, mineralogical and geotechnical properties were employed in assessing the suitability of the clay deposits for potential industrial uses. Mineralogical analyses reveal kaolinite as the dominant clay mineral with quartz as the dominant non-clay mineral. The physical and geotechnical properties indicate that the hydrous and marginal expansive clays are fine-grained (75 μm > 2%), have low to medium plasticity (plasticity index 12.8–40.8%), low density (1.69 to 2.60 g/cm3) and low linear shrinkage (4–6%) on drying and firing. Geochemical analysis shows significant amounts (> 1.0 wt%) of SiO2, Al2O3, Fe2O3, MgO, CaO, and Na2O, and relatively low values (< 1.0 wt%) of K2O, FeO and TiO2. The clays meet the requirements for production of building bricks, roofing tiles, local pottery products and domestic ceramic wares other than ceramic white wares. However, these low grade clays will require a high degree of refining or beneficiation to remove the undesirable minerals to qualify for use in rubber, paper, paint and cosmetic industries.