EFFECT OF CHEMICAL PRETREATMENT ON BACTERIAL DESULFURIZATION OF ASSAMCOAL

Coal from North Eastern Coal Fields of Tinsukia District of Assam was used in tests for bacterial desulphurisation with and without chemical treatment. The coal with 5.5 wt% of total sulphur was treated with aq ueous NH4OH and Na2CO3. The pretreated coal was used for bacterial lea ching with a mixed culture of Thiobacillus. Under various conditions o f bioleaching, desulphurisation was better for the pretreated coal sam ples (namely 35-38 wt%) than for the raw coal (namely 5-27 wt%). Howev er, the major component (organic sulphur) of the total sulphur could n ot be removed. The kinetics indicate the desulphurisation rate for pre treated coal to be higher than that for the untreated coal. (C) 1998 E lsevier Science Ltd. All rights reserved.