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
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.
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.
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.
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
using M Sand for Constructions Which has more advantage than River Sand