Copper Slag – Green Alternative for Building A Modern India

There has been a pressing need to tackle the ever-increasing demands of development from all over the world through innovative and environment-friendly ways. Optimising the consumption of natural resources is a key operational focal point of many organisations nowadays. What has also taken off big time is the alternative and recyclable uses of by-products that are being produced in the factories manufacturing metals and power for nation building. For example, to tackle the issue of depleting sand reserves on the river beds for construction of modern towns and cities, ‘green materials’ like copper slag have been tried and tested to substitute the shortage. These pioneering practices can be seen in the town of Thoothukudi in Tamil Nadu.

Let’s elaborate on it further.

The ‘Tamil Nadu Vision 2023’ forecasts 70% of the population embracing urbanization. It has envisioned 6 major ambitious industrial corridors with a total outlay of INR 150,000 crores (USD $25 billion). A few among the key projects are the Madurai-Thoothukudi and Chennai-Ranipet industrial corridors with an investment outlay of INR 84,000 crores (USD $14 Billion). These will open new doors for investment and development in the state in addition to generating employment opportunities for thousands. All such key industrial projects require huge quantity of fine aggregates (for e.g., sand) which is already a scarce resource. In fact, the state does not even have sufficient reserves to meet the domestic requirement of its ever-growing population. The need for an alternative eco-friendly aggregate is imminent to quell such dynamic requirements.

Have a look at these findings.

  • River Sand: According to a recent survey conducted by an independent consultant (JJL India) around 55,000 trucks are loaded with 400 cubic feet of natural river sand at the various river sand mines, per day as on April 2017. However due to lapsed mining licenses and only a few quarries being operational, construction projects worth around INR 10,000 crores have come to a standstill leading to poor infrastructure development in the state. This has also caused the loss of around 5 lakh jobs.
  • M Sand: This alternate source which is obtained by crushing the rock boulders drawn from natural hillocks, mountains and underground rock deposits also cause detrimental effects on the regional ecology by damaging the natural mountains – the main cause for rainfall and climatic conditions prevailing in the peninsular India.
  • River Sand Import: Though the state is now confident that the import of river sand from the Far-East countries would address the current crisis, it is their last resort and not a sustainable one. Its continuous availability depends on the law of the land from which it is being imported and may be unpredictable. Also, the landing price of river sand drawn by such sources would be too costly.

Copper slag is an economical, established and the most widely accepted alternative to the natural aggregate (sand, crushed from natural rocks). It is finding increasing operational acceptance by the ready-mix concrete manufacturers and in government road projects for concrete applications as prescribed by BIS IS 383:2016 (Bureau of Indian Standards) for the past 3 years now. It is being currently employed in the Madurai – Tuticorin industrial corridor project, thereby, eliminating the need to deplete the existing topography of the region. This will also play a pivotal part in reducing greenhouse gas emissions and global warming by preserving the green cover on hills and the river beds.

  • Copper Slag is an eco-friendly industrial by-product being manufactured in Sterlite Copper, Tuticorin.
  • The Indian company is one of the leading copper manufacturers in the world, catering to electrical, automotive, infrastructure and several other industries.
  • Copper today is an $8 billion industry in India, having created 50,000 direct and indirect jobs and growing at a CAGR of 5-7% per annum.
  • India is expected to be the 6th largest copper market by 2020 with major consumption sectors being – Electrical, Transport and Telecommunications.

Copper slag is non-hazardous, non-toxic and non-leachable material, thereby facilitating its suitability in such applications. It doesn’t seep into the ground water and is not a pollutant. Some of the research findings by reputed institutions alleviate many myths about the material. Here are a few of them.

Institute Test Conducted Results/Outcome
Industrial Toxicology Research Centre (ITRC), Lucknow Leachability & Toxicity Test, Seed Germination Test Found safe for aquatic fauna and flora.

Does not affect early growth of seedling.


Highways Research station (HRS), Chennai Suitability Test for Road Construction Found it to be a suitable material for use as an alternative material for road construction. The Tamil Nadu State Highway completed a trial road stretch of 0.6 Km using copper slag (Tirunelveli – Tiruchendur road) in 2007.
Central Electrochemical Research Centre (CECRI), Karaikudi Corrosion and Leaching Studies on Blended Copper Slag in Concrete. Concluded non-leachability & low conductivity of concrete made of copper slag.
National Council for Cement and Building Material (NCCBM), New Delhi Technical Suitability Study of Copper Slag in Cement Manufacturing Process Found suitability in manufacturing ordinary Portland cement (OPC) and Portland slag cement (PSC).

Contributes in energy saving.

Central Road Research institute (CRRI), New Delhi Detailed Study (For 2 Years) On Usage of Slag as An Alternative for Aggregate Material for Road Construction Applications Study recommended utilization of slag in various layers of road including sub base, sub-grade and pavement layers.
National Metallurgical Laboratory (NML), Chennai Copper Slag Leachability Concluded that it was fully stable and poses absolutely no risk in terms of toxicity for storage.

It can be used as a constituent of cement or bituminous pavement and may be considered for use in Marine applications such as reclamation of both facilities and other land filling applications at Port.

NHAI issued a policy letter for promoting of usage of Copper Slag in road construction.
Structural Engineering Research Centre (SERC), Chennai Application of Copper Slag in Concrete Manufacturing. Concluded that slag possesses properties like river sand and can be used as a partial replacement of sand in ready-mix concrete for better strength and workability in addition to resisting abrasion.
National institute for Oceanography (NIO), Goa Impact Assessment Studies on Utilization of Copper Slag as Reclamation Material for Berthing Facility on Marine Flora and Fauna. Concluded that usage of copper slag would not alter the water quality and biological productivity of coastal water significantly and therefore can be utilized for marine application such as berthing facility.


Times are changing for the better. India’s burgeoning growth on the economic and social fronts have been on an unprecedented rise over the past few decades. Our nation’s tryst with globalisation has led to the conception of sprawling cities and emerging towns for the ever-increasing population. There can be several factors which have sky-rocketed our quality of lives from what it was back a couple of decades ago. But we certainly agree on one thing – progress is imperative in these times and world-class infrastructure has always been its backbone. Looking for green and innovative solutions to address such challenges will improve the environment in the long run.


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