Biodesulfurisation (BDS) of coal by use of Thiobacillus ferrooxidans was examined. For three Argonne premium coals, the % removal of inorganic S was 56-85% when the BDS was carried out for 30 days. An appreciable correlation was observed between the amounts of S and Fe leached. The % removals of S and trace elements obtained for the BDS were comparable to those when an acid-leaching was performed. The amount of acid used for the BDS was much less than that for the acid-leaching.
