Efforts of NTPC for the Introduction of a New Approach in India for the Coal ash disposal in a beneficial and an environmentally acceptable manner in the abandoned open-cast mines

摘要

National Thermal Power Corporation (NTPC) is the largest coal-fired power generator inIndia. NTPC plans to significantly increase its existing installed capacity of 19,935 MWin the near future to meet the market demand leading to the higher and higher generationof coal ash. Today NTPC alone produces about 27 million tons of coal ash and this is onincreasing trend. This warrants NTPC to introduce a new approach for the disposal ofcoal ash in beneficial and an environmentally acceptable manner. This is because oflimitations on the land availability for ash pond disposal, increasing the capacity of theexisting generating units is being constrained, thereby necessitating the evaluation ofalternative ash disposal methods. Thus one attractive alternative is mine back filling. Thiswill drastically reduce new land requirements for ash dykes near the power plant and willreclaim the abandoned mine sites for afforestation and vegetation purposes.Thus, the Center for Power Efficiency and Environmental Protection (CENPEEP) ofNTPC, which is currently working on the Greenhouse Gas Pollution Prevention (GEP)project, in association with United States Agency for International Development's(USAID) has done a preliminary evaluation with respect to the technical, economic, andenvironmental feasibility of haulback from NTPC-Singrauli to the Gorbi Mine.The thermal power station in question is "NTPC-Singrauli", one of the largest NTPCplants with a capacity of 2,000 MW, is generating over 2.5 million tons of ash per year.This study focuses on hauling all the ash generated from the power station back to mine.This study thus developed an approach in terms of technical and economic feasibilityalong with the coal ash characterization, geological and environmental considerations. Ithas been established that it is possible to haulback ash from generating station toabandoned mine pits. Further, it has also been concluded that the coal ash can be used inthe closure and establishment of vegetation on the completed disposal sites as well as onotherwise disturbed mined land.