Abstract

A combination of analytical techniques such as atomic absorption spectroscopy (AAS), X-ray diffraction (XRD), infra red spectral (IR) analysis, energy dispersive analysis of X-ray (EDAX), differential thermal analysis (DTA) and thermogravimetric analysis (TGA) were employed to characterize clays from Odukpani, Cross River State, Nigeria. The samples were also subjected to physico-chemical tests. The results obtained show that the silicon content was the highest and that of manganese the lowest. The silica (SiO₂) content was found to be 47.52% followed by alumina (Al₂O₃) 34.01%, iron oxide (Fe₂O₃) 2.38% and trace amounts of other elements such as Ca, Mg, Na and Mn (0.038, 0.188, 1.78 and 0.00%, respectively). The X-ray diffraction studies showed that the clay deposits consist predominantly of kaolinite and quartz with trace amounts of illites and biotite minerals. The infra red spectral analysis between 400 and 3700 cm^-1 revealed interesting wave numbers and absorption bands. EDAX analysis of the clay samples reveals that Al and Si, were in the ratio of 1:2 whereas other elements like K, Ti and Fe were below detection limits. The thermal analysis revealed thermograms that provided valuable information on the purity of the starting materials and the mode of the reactions of the various clay samples.

Key words: Odukpani clays, atomic absorption spectroscopy, infra-red spectral and energy dispersive analysis of X-ray, differential thermal and thermogravimetric analysis.