Geochemical composition, mineralogy, geotechnical characteristics of some clay deposits in parts of the southern Niger Delta, Nigeria

Clay soil samples from the Afo-Okpella and Okpekpe in parts of the southern Niger Delta were analyzed for their geochemical composition, mineralogical and geotechnical characteristics. X-ray fluorescence analysis, x-ray diffraction analysis and index property tests were carried out to determine elemental composition, mineralogical nature and geotechnical attributes of the clay. The XRF reveals that SiO2 and Al2O3 are the predominant oxides. The XRD analysis shows that kaolinite is the predominant clay mineral with varying amount of quartz also traces of illite, smectite. The geotechnical index test shows that the clay soil samples studied also contains considerable amounts of silt-size particles (18%-70%) which makes them unsuitable in their raw state for use as fillers, raw materials in the paint industries. The clays were generally of medium to high plasticity and medium to high compressibility, however the classification of degree of expansion as regard to percentage linear shrinkage places the entire clay bodies studied in the critical degree of expansion. The study reveals that they are good for the production of quality bricks, ceramics and other industrial usage such as rubber, paper and paint industries.