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Journal of the Southern African Institute of Mining and Metallurgy

On-line version ISSN 2411-9717
Print version ISSN 0038-223X

J. S. Afr. Inst. Min. Metall. vol.108 n.7 Johannesburg Jul. 2008




Comparative study of the influence of minerals in gas sorption isotherms of three coals of similar rank



C. RodriguesI; H.J. PinheiroII; M.J. Lemos de SousaI

IUniversidade Fernando Pessoa, Portugal
IISpringlake Holdings (Pty) Ltd, Petmin Limited, Bryanston, South Africa




This investigation compares the gas adsorption behaviour and capacity of three bituminous coals from South Africa, of similar rank, by assessing the characteristics of the raw coal, as well as the resulting float and sink fractions (at 1.80 cm3/g) obtained by density separation of crushed coal samples. Calculations were also made to obtain the raw coal gas storage capacity from the weighted contribution of both float and sink fractions results, thereby permitting comparison with the analysed results of the raw coal. The study demonstrated that the clean fraction of a coal has the highest capacity to retain gas in the sorbed state, followed by raw coal, and lastly the sink fraction, and re-confirmed previous investigations that showed minerals to be inhibitors of gas adsorption and retention.



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