The Singareni Collieries Company Limited, which has already started using the coal ash, the end product of NTPC Ramagundam, for stowing of the underground mines after extraction of coal since the year 2011 onwards, has now decided to fill the Open Cast Projects with the ash in Ramagundam coal belt.
Accordingly, the Singareni management and NTPC Ramagundam are likely to sign an agreement for the supply of ash generated from the upcoming 1600 MWs (2 x 800) Telangana super thermal power project (TSTPP) to fill the OCPs in the Ramagundam region. Initially, it was decided to fill the OCP-4 in Ramagundam coal belt with TSTPP ash which is all set for commissioning by this year-end tentatively.
The filling of void in OCP mine is an environmentally friendly method of power generation. Subsequent to completion of coal excavation from Medipally open cast mine (OCP-4), it has created a huge void and needs to be filled from environment point of view. Coincidentally, the Telangana power project is coming up and the ash generated from it can be used for mine void backfilling.
New technology
The ash disposal system of Telangana project fully complies with CEA (Central Electricity Authority) guidelines and follows latest and environmentally friendly practices. For sending ash to the mine void, the NTPC is using a new technology called HCSD (High Concentration Slurry Disposal) which is safe, silent, and reliable without any ash spills and contamination. Through this, ash will be transported through small diameter-thick welded pipes in almost paste form in slower velocity by the positive displacement method. This will ensure almost nil chances of leakage and fugitive emission. This system uses less than 20 per cent water compared to a conventional system and thus makes more water available for Ramagundam, the official sources said.
As the mine void is 150 metres below bed level of the river Godavari, there is no chance of contamination. Based on its technical feasibility, the NTPC is acquiring minimum possible private land for the proposed ash pipeline project going through Malkapur village, the sources said and added that if the ash had to be dumped in the ash pond, the NTPC requires several hundreds of acres of land and also cause air pollution with dust emission with the pond.
The officials have also said that the Union Ministry of Environment had also favoured utilisation of the fly ash generated by the thermal power projects for backfilling the mine voids and quarries. The filling of OCPs with ash of NTPC is the best form of protection of the environment, they maintained.
