Physicochemical and Minerological Evaluation of Clay Deposits in Parts of Buan, Southern Nigeria

Abstract

Some clay soil samples from the Buan in parts of the southern Nigeria were analyzed for their geochemical composition, mineralogy and geotechnical characteristics. This research was carried out using modern methods of analysis such as Index properties tests, x-ray fluorescence analysis and x-ray diffraction analysis to determine the physicochemical, elemental composition and mineralogical nature of the clay. The moisture content of the sample fall between 23.6% to 67.79%, the atterberg limits values fall between 20.8% to 51.5%, the activity series show normal clay to active clay, the swelling potentials for the samples show low to high swelling potential, the linear shrinkage of the soil fall between 5.35% to 16.40%, the particle size distribution (PSD) curve for samples L1, L5 and L10 shows a high percentage of sand (58-75%) and a relatively lower percentage of the clay sizes (12-19%). The pH of the samples tested gave relatively high acidity of between 4.7 and 5.9, compared to the typical range of pH of Nigerian soils of 4.8 – 6.9. The XRF study showed that silica and alumina were predominantly in the analyzed samples, with weight ranging from 42.4 to 57.8% and from 9.7 to 28.3% respectively. Alkali oxides Na2O, CaO and K2O occurred in subsidiary amounts. A low proportion of alkali metal oxides indicate the possibility of producing refractory products. The XRD results showed that quartz is the dominant mineral while clay minerals are in a lower proportion. The properties of these clays make them suitable for use in refractory bricks and in sanitary landfills.