Someone once said, “One man’s trash is another man’s treasure,” and the Kerala government’s Autokast Ltd, a ferrous foundry manufacturing unit, is yet another example of how.
According to a 2021 report, the company produces 700 tonnes of foundry waste sand each month. They developed a method for converting sand into bricks that can be used in the construction industry. A technology developed by the Council of Scientific and Industrial Research-National Institute for Interdisciplinary Science and
Technology (CSIR-NIIST) is used to make these bricks.
The manufacturing unit is designed to produce 4,000 bricks per day. While production will initially be around 1,500 bricks per day, the unit will eventually reach its full capacity. The CSIR-NIIST technology uses cement bonding and compression moulding technique to make bricks from waste sand.
Why Silica bricks?
Rising population and subsequent environmental damage to meet the demands of said population is a common issue that developing economies such as India face.
A research paper by Mckinsey & Company titled Environmental and Energy Sustainability: An approach for India predicts “the building construction sector in India would grow at a rate of 6.6% per year till the period 2030 since 80% of India is yet to be built”.
The construction industry’s constant growth is bound to increase demand for construction materials, particularly bricks. To meet this demand, the foundry industries engage in mass production, which generates a lot of waste.
The disposal of waste sand in the environment, typically in landfills, causes direct contamination of soil due to metals. It may also contaminate groundwater resources and the surrounding superficial environment, according to the paper.
According to the Mckinsey & Company report, the penetration of toxic materials in the soil, particularly groundwater, can lead to water-borne diseases.
Studies show that WFS (waste foundry sand) can be used to make clay bricks. The use of foundry sand residuals as aggregates in the production of red clay bricks and tiles was investigated. WFS concentrations of 10%, 20%, 30%, 40%, and 50% were used to make clay bricks. According to the report, the best results were obtained in samples with 30% and 40% WFS.
According to Autokast Ltd and other research, Silica bricks are eco-friendlier and save tonnes of WFS from being dumped in landfills.
According to a Science Direct research paper, the process of making bricks includes combining clay-sand mixtures, forming bricks, drying and firing the bricks. Because the bricks are “low cost, have high creep resistance, and cause low pollution,” they are most commonly used as refractories.
The project was undertaken as part of the Council of Scientific and Industrial Research’s ‘Waste to Wealth’ research programme, with the goal of setting an example for
other manufacturing units to save the environment one silica brick at a time (CSIR).
