Jamalganj Coal refers to the coal deposit found at jamalganj upazila of joypurhat district in northwestern Bangladesh. Coal was discovered in 1962 at depths of between 640 and 1,150m below the surface. After the discovery, appraisal work to determine the areal extent and total reserve was carried out by further drillings. This resulted in the outlining of the Jamalganj coalfield with an areal extent of 11.66 sq km. The total reserve of coal in the field is estimated at 1,053 million tons. This is the largest coalfield so far found in Bangladesh.
Jamalganj coal is a high volatile bituminous coal and has an average calorific value of 12,100 btu/lb. It is a good quality Gondwana coal with little sulphur content. Proximate analysis indicates that it has 33-54% (average 47%) fixed carbon, 30-40% volatile matter, 10-60% (average 22%) ash and an average of 0.65% sulphur.
There are seven coal layers (seam) in the Jamalganj coalfield and these occur interbedded with hard sandstone with little shale. Individual coal seams range in thickness from less than 2 to about 46m. The coal seams commonly contain a variable number of non-clay partings, mainly carbonaceous mudstone.
Jamalganj coal is Permian (about 250 million years before present) in age and belongs to the gondwana group, similar to the coal found in the large coal fields in the northeastern Indian states of West Bengal and Bihar. The coal bearing Gondwana rocks in the Jamalganj field occurs in a fault bounded half graben basin within the pre-cambrian basement. Geologists believe that during the Permian time a large river plain with thickly vegetated swampy areas existed in the northwestern part of Bangladesh including Jamalganj. Carbonaceous materials deposited in the swampy areas were buried and subsequently converted into coal by burial compaction and temperature. The extent of coal layers is believed to have been larger, but part of it was eroded in the geological past leaving the currently preserved coal in the fault-bounded basin.
Feasibility studies for the economic extraction of Jamalganj coal were carried out by the consultants Fried Krupp Rohstaff in 1966 and by Powell Doffryn in 1969. It was suggested that although it is technically feasible to mine Jamalganj coal, it would not be economic to do so because of great depths. The idea of mining Jamalganj coal was abandoned after the discovery of coal in much shallower depths in the Dinajpur-Rangpur area. However, it is believed that Jamalganj coalfield can be developed for coal bed methane extraction. [Badrul Imam]
See also coal bed methane.