CSIR-NIIST's technology turns industrial waste into eco-friendly building materials

Continued scientific studies resulted in a process for making bricks through a simple cement bonded compression moulding technique.

Logo of CSIR-National Institute for Interdisciplinary Science and Technology (NIIST) in Thiruvananthapuram Photo | Express

THIRUVANANTHAPURAM: Foundry sand waste, a by-product generated in large volumes by metal casting industries in the country will no more be labelled as pollutants but will turn into an eco-f­riendly and cost effective alternative for the booming construction sector.

Using technology devised by Thiruvananthapuram-based central research institution CSIR-NIIST, tons of foundry sand waste would be turned into
high strength bricks that meet the IS 1077 standards. As a first step, the institution has joined hands with a private company to set-up a brick
manufacturing plant to utilise nearly 30 tons of silica sand on daily basis to produce up to 5,000 bricks per day.

Speaking about the technology, C Anandharamakrishnan, Director, CSIR-NIIST said it would not only address an environmental challenge but also
create an opportunity for industry to participate in nation-building through green innovation. CSIR-NIIST scientists systematically studied the reactivity of the foundry sand waste with cement, lime, gypsum, and polymer modified binders and documented the critical parameters such as strength, density, water absorption properties usually required for building bricks.

The continued scientific studies resulted in a process for making bricks through a simple cement bonded compression moulding technique. The process developed by CSIR-NIIST was transferred to a Coimbatore-based company as part of a know-how agreement.

CSIR NIIST also technically assisted to procure the efficient machinery and design the production plant. "The brick products completely avoid
usage of materials such as natural clay, M-sand or gravel. The bricks can also be shaped in aesthetically appealing colors for architectural
interior design applications," said a scientist associated with the project.

According to CSIR-NIIST officials, the cost-effective bricks would be of huge benefit to various government-sponsored housing projects including
the Life-Mission Project of the government of Kerala. "The NIIST technology also can be used to make paving tiles, hard aggregates and
interlocks," the scientist explained.