NTPC develops Geo-polymer aggregate from fly ash

NTPC Limited has successfully developed a Geo-polymer coarse aggregate from fly ash. Aggregates are commonly used in civil engineering projects to stabilise terrain.

An NTPC statement said that they find extensive usage in the construction industry. “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 reduction of water consumption,” a company statement said.

India’s demand for these aggregates touches close to 2,000 million metric tons mark 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, the statement said.

In India, every year approximately 258 million tonne of ash is produced by the coal fired thermal power plants. Out of this around 78 per cent of the ash is utilised and the balance remains unutilised which remains in ash dykes. NTPC said that it is exploring alternate ways to utilise the remaining ash which includes the current research project to generate aggregates using more than 90 per cent ash.

NTPC also said that its research project on production of Geo-polymer coarse aggregate from fly ash has met the statutory parameters of Indian Standards and was confirmed by National Council for Cement and Building Materials (NCCBM).