Fly ash is a byproduct of power generation with coal. Sustainable ash utilisation is one of the key concerns at NTPC. The Ash Utilisation Division (AUD), set up in 1991, strives to derive maximum usage from the vast quantities of ash produced at its power stations. The ash is now being looked at as a commodity that could generate wealth for the company in the long run. The AUD proactively formulates policies, plans and programmes for ash utilisation. It further monitors the progress in these activities and works for developing new segments of ash usage. Ash Utilisation Cell at each station handles ash utilisation activities.
Research has shown that the quality of fly ash produced at NTPC’s power stations is extremely good with respect to fineness, low unburnt carbon and has high pozzolanic activity and conforms to the requirements of IS 3812 - 2003-Pulverized Fuel Ash for use as Pozzolana in cement, cement mortar and concrete. The fly ash generated at NTPC stations is ideal for use in the manufacture of cement, concrete, concrete products, cellular concrete products, bricks/blocks/ tiles etc.
To facilitate easy availability of dry fly ash to end users, dry fly ash evacuation and safe storage system have been set up at coal based stations. Further, at NTPC-Rihand facility for loading fly ash into rail wagons has been provided so that fly ash can be transported in bulk quantity through the railway network. Such facility is also being provided at all new upcoming coal based power stations. NTPC also offers all types of ash along with infrastructure facilities enabling evacuation of ash free of cost, wherever feasible.
Over the years, ash consumption level has reached from meagre 0.3 million ton in 1991 - 1992 to 30 million tons in 2012-13. The important areas for this utilisation are cement industry, bricks industry, road embankment, mine filling, land development and ash dyke raising. It is also a source of micro and macro-nutrients in agriculture.
The Ministry of Environment & Forests (MoEF), Govt. of India vide its notification (amendment) dated 3rd Nov 2009 has made it mandatory:
Major Projects where fly ash has been utilised
Within 100 Km radius of a Thermal Power Plant
- To use fly ash based building products such as cement or concrete, fly ash bricks, blocks, tiles etc. in all construction projects
- To use fly ash in road or flyover embankment construction
- To use fly ash in reclamation of low lying areas
Within 50 Km radius of a Thermal Power Plant (By Road)
- To use fly ash in back filling of underground and open cast mines
Financial institutions to include a clause in their loan documents for compliance of this notification
Road Embankment Construction & Filling Works:
- 67 lakh Cubic Meters (Cu.M) of pond ash from NTPC Unchahar Station has been utilised in Allahabad By-pass Road executed by NHAI.
- 20 lakh Cu.M of pond ash from NTPC Badarpur Station has been used in Noida - Greater Noida Expressway
- About 1.5 lakh Cu.M of pond ash from Indraprastha thermal power station has been utilised in 2nd Nizammudin approach road embankment
- About 5.0 lakh Cu.M of pond ash from NTPC Badarpur Station has been utilised in Yamuna Expressway & Badarpur Flyover
- More than 15 lakh Cu.M of pond ash has been used by Delhi Metro Rail Corporation (DMRC) in their Shastri Park rail car depot from NTPC Badarpur Station.
- Fly ash from NTPC Dadri Station is being utilised in all underground concrete works by DMRC for its metro projects in Delhi.
- Fly ash is being utilised by all Ready Mix Concrete (RMC) Plants
- Fly ash used by ACC Ltd. in concrete road at its RMC Plant in Greater Noida
- Fly ash used in concrete road construction from Dehra Jhal to NTPC Dadri
Building Construction Works:
- Administrative Building of Greater Noida Industrial Development Authority (GNIDA) constructed with fly ash bricks.
NTPC’s own Buildings constructed with fly ash bricks
- NETRA office at Greater Noida
- 'D' Type residential quarters at Noida Township
- Northern Region Headquarter building at Lucknow
- All Projects and Township construction
- Private real estate developers in various metro cities viz. Pune, Visakhapatnam & NCR areas use fly ash bricks for construction of residential complexes.
- South Balanda Mine being filled with ash from NTPC Talcher-Thermal Station.
NTPC is constantly looking at innovative and new ways to utilise the ash generated. Following research studies have been / are being conducted for development of new segments having long term potential of ash utilisation:
To demonstrate use of ash in construction of railway embankment, research study was carried out in association with the Central Road Research Institute (CRRI), New Delhi. The design of railway embankment developed by CRRI was validated by conducting Centrifuge Model Tests at IIT Bombay. Construction of railway embankment for NTPC’s Merry Go-Round (MGR) rail track for coal transportation is planned at NTPC Kahalgaon and NTPC Talcher-Kaniha.
- Feasibility study is being conducted at Talcher-Kaniha by M/s Desien for finalising the techno economically optimum mode of transporting ash from power plant to mines on long term basis. Infrastructure shall be created accordingly for filling of mines with fly ash from NTPC Talcher- Kaniha.
- Research study is being done by the Central Institute of Mining & Fuel Research (CIMFR), Dhanbad for taking up technology demonstration project for random filling of ash from NTPC Ramagundam with Mine over Burden (MOB) at Medapalli Mines.
Pre-stressed Railway Concrete Sleepers:
Use of fly ash in the manufacture of pre-stressed railway concrete sleepers demonstrated in association with IIT Kanpur.
Ash based Bituminous Road:
Demonstration project for construction of fly ash based bituminous roads have been taken up in association with CRRI at NTPC Badarpur and Dadri.
Flux bonded Bricks/Tiles:
Research study for use of fly ash in flux bonded bricks/tiles has been conducted at NTPC Ramagundam, in association with NIIST Trivandrum.
Use of fly ash in manufacturing of HDPE products taken up by Vindhyachal through IIT Delhi.
Showcase Projects on use of Ash in Agriculture:
Use of fly ash in agriculture, as a soil modifier and source of micro and macro nutrients, has been successfully demonstrated through “Show case projects” in collaboration with the local farmers under the direct guidance of reputed agriculture institutions/universities.
- At NTPC Simhadri in association with Annamalai University
- At NTPC Unchahar in association with N.D University of Agriculture & Technology, Faizabad (U.P)
- At NTPC Talcher – Thermal in association with Annamalai University
- At NTPC Vindhyachal in association with Annamalai University
- At NTPC Dadri in association with Annamalai University
Various crops have been grown and harvested in varying agro-climatic conditions and different soil-crop combinations and following increase in crops yield has been successfully demonstrated:
|S.No.||Name of Crop||Increase in Yields|
|1||Wheat||16 - 22%|
|2||Paddy||10 - 15%|
|3||Sugarcane||20 - 25%|
|4||Banana||25 - 30%|
|5||Maize||More than 30%|
|6||Vegetables||10 - 15%|
The AUD is constantly at work to promote and popularise multifaceted utilisation of fly ash as a resource material in various segments and to create awareness among the prospective users & entrepreneurs for the use of ash. It organises regular workshops and lecture series for potential users.
Here are some of the campaigns undertaken by them in the recent past:
- NTPC Guide for Users of Coal Ash
- Fly Ash Bricks – Modern Building Material; Towards Cleaner Environment
- Fly Ash for Cement Concrete – A Resource for High Strength and Durability of Structure at Lower Cost
For awareness creation advertisements in National dailies are released from time to time on various application of fly ash such as: