Extent of lead in high sulphur Assam coals

This study has been undertaken to understand the precise nature of association of lead in high sulphur Assam coal. Sequential extraction of lead with ammonium acetate, HCl and RuCl3 solutions have been carried out. RuCl3 has been used as a suitable reagent for the extraction of lead. It is found that treatment of sample with CCl4 increases the extraction of lead by RuCl3 solution. The amount of lead in the coal studied varies between 43.2 and 50.4ppm. It has been found that lead is predominantly occurring in coals in association with organic matter and needs concerted attention to understand its bio-availability. The chemical principles involved therein are also discussed.