Eguasa Samson AGBONGIAGUE

There has recently been an increase for the usage of clay minerals. Hence, the driving force for this research work which was carried out to determine the chemical composition and basic geotechnical and physical characteristics of Ogiso and Okhoro clay deposits in Edo State, Southern Nigeria. In this study, ten (10) fresh clay samples were randomly collected, three(3) from Okhoro and seven(7) from Ogiso and were subjected to X-ray-Diffraction (XRD), Xray-Fluorescence (XRF) and geotechnical analysis to determine their mineralogy, chemical composition and engineering behaviour so as to evaluate their economic potential. The XRD analysis revealed that the basic mineralogy of the samples studied is made up of kaolinite, quartz and hematite with traces of zircon, illite and anatase occurring in minor amounts in some of the samples. The XRF analysis revealed the occurrence of 10 elemental oxides and 10 elemental trace elements. The major elemental oxides include SiO2 with a range of 55.82 – 61.41wt %, Al2O3 with a range of 21.12 – 24.42% and Fe2O3 with a range of 6.05 – 9.06% while the major elemental trace elements are zircon with a range of 0.89 – 1.78wt%, zinc with a range of 0 – 1.51%, copper with a range of 0 – 1.39wt% and chromium with a range of
0.01 – 0.11wt%. The geotechnical analysis revealed that the samples are of low to medium plastic inorganic clay with percentage fines fraction of 76.84 – 78.45%