Demolition of Supertech Twin Towers 80,000 tonnes of debris left behind, of which 28,000 tonnes will be scientifically processed by Re Sustainability and Recycling Pvt Ltd at the Concrete and Demolition (C&D) Waste Plant in Noida, formerly known as Ramkey Reclamation and Recycling Pvt Ltd. Was known.
The company, part of the Hyderabad-based Ramky Group, is known for implementing a scientific process for the recycling of concrete and demolition waste. In 2019, it was awarded a tender by the Noida Authority, and a 15-year concession agreement was signed between the two on a public-private partnership (PPP) model.
The plant, located in Noida’s Sector 80, took five months to set up between March and August 2020 and the processing of the waste began on October 15, 2020. Spread over five acres, it operates seven days a week. The company has similar plants in Hyderabad, Nagpur, Kolkata, Tirupati and Vijayawada. In the last two years, the plant has recycled 2 lakh metric tonnes of waste.
Mukesh Dhiman, Project Manager at the plant, has nearly 10 years of experience in C&D waste management, and leads a team of 16 people including engineers, administrative staff, field and plant operators along with 30 laborers – 10 in the plant. deployed and in the rest of the region.
To process debris from the Twin Towers, workers would work between 8 a.m. and 8 p.m., with two hours before and after the shift devoted to performing maintenance work at the plant.
“It is a very rapid process; About 250-300 tonnes of concrete debris will be processed per day from the demolition site. But first, Edphis (engineering, demolition firm) will separate the steel from the rubble because the plant can only process concrete. We have a capacity of 850 tonnes per day… Debris collected from the demolition site will be brought to the plant, where it will be first weighed on the weighbridge. In pursuance of this, the debris will be lowered onto a vibrating grizzly feeder hopper, which in the form of vibration separates the debris and is carried to a jaw crusher,” Dhiman told The Indian Express.
“About 10-15 trucks, each carrying 20 tonnes of concrete debris, will be sent by Edifice for processing at the plant; The Grizzly Hopper can accommodate 20 tonnes of concrete debris at a time, with each block of concrete not exceeding 200 mm,” he said, adding that the machine can process 20 tonnes of concrete in 10-15 minutes.
He further explained the complex process of recycling waste:
After entering the premises, the truck is weighed at a weighbridge, which is connected to a control room of the Noida Authority and fed real time data there. As the vehicle is about to enter the processing unit, it gets drenched in water.
The debris is then unloaded into the grizzly hopper in the processing unit. It is crushed into small pieces by a jaw crusher installed at the bottom of the Grizzly hopper – each block of concrete may measure no more than 200 mm. From this size, concrete bits are crushed into smaller sizes – 10 mm, 20 mm and 40 mm. These are called recyclable aggregates, which are important for the formation of sand.
These various recycling aggregates are separated and transferred through various conveyor belts and collected separately.
In these aggregates, 10 mm, 20 mm and core sands are mixed with cement and hardening chemicals to form interlocking tiles, which are used to make pavements. The mixture is placed in molds, wrapped in a large sheet of plastic, and within 12 hours, the final product is ready. The plant manufactures 2,500 tiles per day. Dhiman said that as an alternative to red bricks, bricks called CC bricks are also made from the same mixture.
Aggregates of 20 mm and above 40 mm are used for the manufacture of granular sub-base, which is the foundation for building roads, and also used for filling quick sanding places. This whole process is guided by Wet Waste Technology as per C&D Waste Management Rules, 2016.
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Sand manufacturing process:
When concrete debris is poured into a jaw crusher, it converts it into aggregates measuring 10 mm, 20 mm and 40 mm. To convert the aggregates into sand, they are again washed with water and fed into a hydrocyclone, a device that generates centrifugal force and separates the sand/mud from the water. About 70,000 liters of water from the sewage treatment plant is used in the manufacture of sand as well as final products such as tiles and bricks. 70% of this water is reused in the plant. The solution from the plant is treated with a chemical that separates the water from soil and other particles and is ready for reuse.
The plant uses a number of equipment to break down and recycle concrete. These are grizzly feeder hoppers, a jaw crusher that crushes 200 mm of concrete into smaller pieces, a cone crusher that is also used to break large pieces of concrete into finer pieces, a screener that crushes solid materials such as plastic or rags. helps prevent. Entering the plant and a hydrocarbon.
According to sources, a processing fee of Rs 156 per metric tonne will be levied on Supertech Ltd by the Noida Authority for processing C&D waste at the plant. It will take three months to remove the debris from the site.