The 2×600 mw Singareni Thermal Power Project (STPP), a subsidiary of the Singareni Collieries Company Ltd., at Jaipur in Mancherial district is evolving into one of the most environment-friendly coal-based power plants by putting into use the entire quantity of fly ash and bottom ash generated by it.
Instead of allowing the fly ash to get mixed with the atmosphere polluting the air, water and soil in the plant’s surrounding areas, the project management has been collecting it, the dust with less than 53 micron particles generated with burning of coal as part of the process of power generation, through modern electrostatic precipitators (hoppers). According to STPP officials, the fly ash collected in that manner was being stored in the silos maintained for the purpose before giving it away free of cost to cement companies and brick-making units.
The power plant is supplying about 4,000 tonnes of fly ash every day to cement companies including Orient, Kesoram and others. Officials explained that cement companies were using fly ash as 30% composition of the cement. Besides, the brick-making units were also using fly ash on a large scale to manufacture cement bricks.
The ash with more than 53 micron particles is collected at the bottom of the furnace as slurry after getting mixed with moisture. About about 1,500 tonnes of it generated at the power plant was being transported to closed underground coal mines for sand stowing or the process of filling the exploited mines to prevent caving-in of the surface over the mines and also to prevent spread poisonous gases inside.
Use of bottom ash (slurry) for sand stowing of the closed underground mines was also saving the scarce resources of river sand, which used to be filled in the exploited mines in the past, the STPP officials stated. It was also saving on the quantity and costs of pumping water to fill the closed mines with sand.
According to SCCL Chairman and Managing Director N. Sridhar, they were utilising almost entire quantity of fly and bottom ash generated by the power plant as part of the company’s environment-friendly measures. Besides, plantation was also being taken up on a large scale on the entire area of STPP.
The STPP officials explained that they have created sort of a record by utilising over 91% of the fly and bottom ash generated by the power plant in 2017-18.
Of the 21.91 lakh tonnes of ash generated last year, about 19.94 lakh tonnes of was utilised including 7.97 lakh tonnes for cement and ready mix concrete units, 7.37 lakh tonnes for sand stowing, 1.3 lakh tonnes for bricks and blocks units, 1.85 lakh units for other ash-based industries and 1.44 lakh tonnes for other purposes.
