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Speciation of coal cotton ash from Okaba in Kogi State Nigeria was carried out using flame atomic absorption spectrometry. Results of this research showed that the elements studied (Cr, Fe, Cu, Ni, Pb, Cd and Zn) were all observed in at least three fractions of the sequential extraction procedure. Pb showed more presence in the exchangeable fraction (80±0.03 µg/g) which is a serious problem to plants and human due to weathering activities in the soil. Most of the elements with high concentration in the residual fractions were found to be thermally stable and of low volatility (Cu and Zn). Chromium occurred mostly as a reducible fraction (80±0.02 µg/g) while Fe occurred mostly as bound to carbonate species. Cadmium was generally low in all the fractions analysed. This trend may be attributed to high volatility of Cd species. Similarly, Ni had a distribution in all the fractions with the highest in the reducible fraction (39±0.01 µg/g) and lowest in the carbonate bound fraction (24 ±0.01 µg/g). The exchangeable fraction of the elements studied is consistent with previous studies of coal bottom ash speciation. The ash matrix may also have contributed to a significant rise in the concentration of Ni at the exchangeable fraction thereby leading to significant variations in metal concentration over the ash particle.

The distribution of a number of trace and major elements in the shale and coal of differing seams in Okaba, Kogi State, Nigeria, was studied using energy dispersive x-ray fluorescence spectrometer. The study was necessary to compare the quality of Okaba coal to world standards of coal quality. Major elements of Al, K, Ca and Fe showed concentration ranges of 5.93±2.49-8.42±0.003 mg/g, 0.18±0.46-2.16±0.0 mg/g, 0.53±0.41-2.23±0.35 mg/g and 6.05±0.004-18.28±1.2 mg/g respectively. The mean concentrations are 7.24mg/g (Al), 1.25 mg/g (K), 0.91 mg/g (Ca) and 11.86 mg/g (Fe). These values are clearly above the recommended concentrations in coal quality standards and for air emission standards by the World health organization. Trace metals of Ti, Cr, Mn, V, Ni and Cu showed concentration range of 0.84±0.

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