Vol. 2, Issue 8 (2015)
Studies on the extender properties of some selected local clays in Nigeria
Author(s): Iheoma C. Chukwujike, Stanley O. Nwakpa, Jerome U. Odo
Abstract: The applications of clay minerals in the various process industries, engineering, petroleum discovery, recovery and refining, and others, are closely related to their structure and composition. Important characteristics relating to applications of clay minerals are particle size, surface chemistry, particle shape, surface area, and other physical and chemical properties specific to a particular application such as viscosity, colour, plasticity, green, dry and fired strength, absorption and adsorption, abrasion, and others. The properties of two different clay minerals Nsu and Ihitte-Uboma have been studied. The clay minerals were sundried, crushed, calcined at 550, 650, 750, 850, and 950 ºC and sieved to a particle size of 0.075mm and characterized. The physical (specific gravity, pH, refractive index, oil absorption), and chemical composition of the clay were also studied. Results showed that the specific gravity, and oil absorption ranged from 0.52885 - 0.784 and 59.26 - 51.94 respectively, and were of good standard according to Nigeria industrial standard (NIS). The pH of the minerals, Sample A and B were determined to be 5.06 and 4.79 respectively. From the result, the local clays were slightly acidic in nature. The refractive index of the two different clay samples were found to be 1.7 and 2.0 which compares with the true prime pigment such as titanium dioxide (TiO2) with refractive index near 2.75. XRF results of the clay samples showed that the major oxides present in the clay minerals were silica and alumina oxide which increased in percentage with increase in calcination temperature, while other oxides were found to be in trace quantity.