�Local coal extraction for power generation is neither feasible nor cost-effective"- a recent remark from State Minister for the MPEMR Mr. Nasrul Hamid comes as no surprise. Mr Nasrul has probably had drawn such conclusion based on dismal mining experience in Barapukuria. He might also take consideration of recently completed mine feasibility study in Dighipara coal field. While this statement comes as surprise to many but not to the industry insider with practical experience in this field, who are long opine that the geological setup of the coal bearing basins of Bangladesh don't permit economic extraction of coal using underground mining method. Bangladesh needs to explore alternative mining methods, and where feasible, open cut mining would be the best possible option to recover its limited mineable resource. The underground mining experience and the mine feasibility study have just re-established the obvious outcome - "underground mining is not the viable option for Bangladesh�
Underground option not delivering : The coal basins in Bangladesh are usually of asymmetric half-graben sedimentary basin, bearing coal measures of Permian age. Three credible mine feasibility studies, so far completed, have extensively explored Barapukuria, Dighipara and Phulbari coal fields and established the resource base to international resource classification standards. The deposits are characterized by multiple coal seams with the major one account for about 60-70% of the estimated resource. This is the 'seam of interest' for underground mine planning as other seams are technically not feasible to mine and leave no option but to be left unmined. Thus a sacrifice of about 30-40% of the valuable resources is forced to make at the very first stage of underground mine planning.
Seam thickness and equipment technology also limit resource recovery and rate of production from the Target Seam. The proposed underground mine planning in Dighipara sets the target of 90 MT of coal recovery. The planned recovery, if achieved, would be about 21%of the mineable reserve of the Target Seam and overall only 12% of total estimated reserve of 706 MT. Barapukuria, the lone operational underground coal mine, so far over its 15 more years production life has only recovered a total of about 11MT at an annual average of 0.7MT. This is how underground mining delivers or projected to deliver for Bangladesh. The extreme poor recovery, leaving 90% coal unmined, is understandably neither feasible nor cost effective. It's just a costly wastage of valuable national resources.
The cost of production in underground mining is inherently higher, which could only be possible to offset by achieving higher coal resource recovery and by increasing production scale. But as coal recovery is extremely poor and production rate is relatively low, the obvious outcome is excessive high production costs, which is reported to be more than US$ 100/tonne in Barapukuria and would be even higher in the proposed Dighipara mine. This is neither economic nor justifiable in any sense while in international market coal price is well below the cost of coal mining in Bangladesh.
Coal based power project always prefers a secured and steady supply of coal at competitive cost. Underground mining in Bangladesh fails to deliver such supply security and thus fails to attract potential investor to setup large coal fired power plant based on domestic coal. Barapukuria Mine, which had all the potential to support large scale power generation, is now even struggling to feed only 525 MW mine mouth power plants. This is just a 'lost opportunity' for the country because of choosing inappropriate mining method.
Open cut option to deliver: Then what is the best option for Bangladesh to mine its limited valuable coal resource? A close look at Phulbari open cut mine plan is worth useful at this point when underground mining is considered not to be feasible and cost effective.
Phulbari has an in-situ resource of 572 MT of high-quality bituminous coal. The proposed open cut mine plan sets the target of recovering 475 MT of ROM coal, which represents about 83% of the total resource. The mine with such high amount of recoverable reserve could potentially be the powerhouse for country's primary fuel supply and bring a balance between import and domestic coal supply mix. Just imagine how many Barapukuria size mine requires to match with the coal recovery of Phulbari open cut mine!
Open cut mining in Phulbari is expected to deliver reliable and stable supply of large quantities of coal (15 Mt/annum at full production rate) for a period of over 30 years. The cost of production, reported to be less than US$50/tonne, is far lower in comparison to that of underground mine options. This is an attractive proposition for any large-scale power generation project where long term fuel supply is ensured, coal quality is consistent, and price is competitive. A study revealed that the Phulbari mine production alone can support generation of 6000 MW of electricity using latest ultra-supercritical plant technology, which represents a third of country's projected coal fired power generation target (19,000 MW by 2041). This is how open cut mining makes the difference - in terms of resource recovery, supply security and power generation potential.
Bangladesh needs coal to meet its planned coal fired generation target. However, it is always a preferred and cost-effective option to use domestic coal, either entirely, or in part to supplement import sources. But domestic coal supply so far seems uncertain because of poor outcome of underground mining: the recovery is poor; cost of production is high and thus not feasible and cost effective for power generation. Now it is time to look into the other mining options- the Open Cut Mining, which offers better economics, supply stability and reliability over the longer period. The Phulbari mine plan presents the opportunity to compare how open cut mining in similar geological setup could deliver best for the country.
Zubayer Zaman is a Geologist
