How manufactured-sand help reduce indiscriminate sand mining and saving ecosystems

Manufactured Sand

River beds

There is an urgent need to protect the environment by protecting the river beds, but the construction industry needs sand. Manufactured sand is the solution to this problem. The manufactured sand industry has potential in the region that boasts of several blue metal quarries. Blue metal is the raw material for manufactured sand. Listing out the environmental degradation caused by exploiting river sand, 18 lakh wells in the southern region turned useless since groundwater level dipped alarmingly as river sand, the natural aquifer, was depleted from rivers.

Water table, which was at 50 ft or so, fell to 600 ft in Madurai. There is no water even for agriculture purposes. The government agencies should start taking up construction activities using manufactured sand in place of river sand. Manufactured sand is superior to river sand since the former has better grip in concrete and free of silt and organic impurities. Many big projects have been carried out with the use of the manufactured sand. Public should be sensitised about using it in place of river sand.

M Sand (Manufacture Sand) and its Advantages

What is manufactured-sand, or artificial, or engineered-sand, as it is described? M-sand is produced by passing boulders and stones through a series of jaw and cone crushers for size reduction and then fed into vertical shaft impact (VSI) crushers where they are pulverized further to the size of sand. The VSIs crush them to cubical and angular particles. In certain markets, this is flogged off as m-sand; it’s a masquerade. This process is incomplete From the VSI stage, the sand has to further go through a process of elaborate washing to remove dust and flaky particles Washing in a hydro cyclone process is apparently critical to the entire sand manufacturing process as it effectively removes excess ultrafine of minus 75 microns from the feed material. Ultrafine can be detrimental to the making of concrete.

Manish Bhartia, MD of CDE Asia, has introduced an array of high-performance crushers and washers in India over the past few years. He says the sand thus washed and dewatered is impurity free and Ready-Mix Concrete (RMC) ready. His manufacturing unit in Kolkata is jointly promoted by CDE Global of the UK and the Bhartia family.

Apparently these machines with washers that also help in dousing dust at production sites are a class apart from the crude equipment used at stone quarries.
That the concept of manufactured-sand is gaining traction can be gauged from the fact that, since 2007, when Bhatia began operations, he has been involved in over 60 crushing projects. One of his anchor clients is the Bhopal-based Dilip Buildcon which operates a cluster of 15 plants across the region.

Bhartia estimates that the collective output of msand across all plants would be merely 10 million tonnes per annum (Mtpa). “Of this barely 25 per cent of manufactured-sand produced comes into the open market,” he says. The rest are consumed in-house by large developers and RMC units. The demand for sand is estimated at 500 Mtpa. The nascent industry is just about scratching the surface.

While m-sand gains traction in the market, the idea of abolishing the stone quarry bit in the system seems quite enticing. This is precisely what IL&FS Environment, a subsidiary of IL&FS, one of India’s leading development and finance companies, is doing.

IL&FS is propagating the use of construction and demolition (C&D) waste for the production of m-sand and other aggregates. It is operating India’s first C&D waste recycling facility in Delhi with a capacity of 2000 TPD.

C&D waste is a huge problem in our metro cities. Delhi alone generates over 5,000 tonnes of C&D waste every day. Where does this waste go? It is surreptitiously dumped along roadsides or in water bodies, and in Mumbai, into stretches of mangroves along the seashore. The recent flooding of Chennai can also be partly attributed to this trend.

In Navi Mumbai, if construction debris is cleared out from all the stretches it is dumped in, the city can recover land worth Rs 6,000 crore.

L&FS Environment claims that its C&D waste management facility has helped save over 25 acres of land valued at Rs 250 crore. Its plant has processed over 20 lakh tonnes of C&D waste since it started operations and has recovered/recycled 95 per cent of the incoming waste. Enthused by the results of the pilot C&D recycling plant, several agencies including the PWD, Delhi Metro and municipal bodies have commissioned IL&FS Environment to setup and operate similar plants.

The only impediment to the adoption of recycled-sand (r-sand) has been the absence of clear government guidelines on the usage of recycled products as in the US or the EU. This has been addressed to an extent now: the Delhi government has issued an advisory to all departments to use a minimum of 10 per cent of recycled C&D waste in construction. It’s about time to craft national guidelines on C&D waste.

While the transition from river–sand to manufactured– sand and recycled–sand is a good augury, there are environmental issues that remain to be addressed. “It is essential to ensure that these new genre plants adhere to strict pollution norms. Communities living near or around these plants are already restive,” says Sumaira Abdulali of the Mumbai-based Awaaz Foundation that has been campaigning against illegal sand mining for years.

A few plants on the outskirts of Pune have already been forced to shut down by agitating farmers.

So, Start using M Sand for Constructions Which has more advantage than River Sand

Written by Tavara