NTPC develops Geo-polymer aggregate from fly ash

NTPC Ltd, India’s largest power producer and a PSU under the Ministry of Power has successfully developed Geo-polymer coarse aggregate from fly ash. The development will help in replacing natural aggregates reducing the impact on the environment.

NTPC’s research project on the production of Geopolymer coarse aggregate from fly ash has met the statutory parameters of Indian Standards and was confirmed by the National Council for Cement and Building Materials (NCCBM).

NTPC has successfully developed Geo-polymer coarse aggregates as a replacement to natural aggregates. The technical parameters as per Indian standards for its suitability to use in concrete works were tested by NCCBM, Hyderabad and the results are in the acceptable range.

The development is NTPC’s R&D achievement in expanding the horizon in ash utilization.

India’s demand for these aggregate touches close to the 2000 million metric tons marks every year. The aggregate developed by NTPC from fly ash will help in meeting the demand to a great extent and also will reduce the impact on the environment caused by Natural aggregates which require quarrying of natural stone.

In India, every year, approximately 258 MMT of ash is produced by coal-fired thermal power plants. Out of this around 78% of the ash is utilized and the balance remains unutilized which remains in ash dykes. NTPC is exploring alternate ways to utilize the remaining ash which includes the current research project to generate aggregates using more than 90% ash.

The Geo-polymer aggregates find its extensive usage in the construction industry turning the ash eco-friendly. These aggregates are extremely environment friendly and do not require any cement for application in concrete where the fly ash based Geopolymer mortar acts as the binding agent. The Geo-polymer aggregates will help in reducing carbon emission and has great potential for the reduction of water consumption.