Anil Agarwal-promoted Sterlite Industries India Ltd (SIIL) has found a new business avenue at its copper smelting plant at Tuticorin, in Tamil Nadu. The company is planning to promote a waste product — the copper slag — as an alternate material for concrete applications. Sterlite has already started supplying it to cement manufacturers and is now targeting it at road, abrasives and other industries.
The Tuticorin plant of Sterlite is the ninth largest smelter in the world and the largest integrated copper rod producer in Asia. Presently, the plant has a capacity for 400,000 tonne per annum and the company plans to double it for an investment of Rs 2,500 crore.
The company said, the key raw material for copper smelter is copper concentrate which mainly consists of copper, iron and sulphur. During the smelting operations, iron is removed as iron silicate which is known commonly as copper slag (ferro sand). According to scientific estimates, for every tonne of copper metal produced, around 1.8-2.2 MT of slag is generated, said Ramesh Nair, chief operating officer, Sterlite Industries India Ltd.
“With the increasing scarcity of river sand and natural aggregates across the country, the construction sector has been under tremendous pressure to explore alternatives to these basic construction material to meet the growing demand of infrastructure works.”
States like Kerala, Maharastra and Gujarat have already banned river sand mining owing to its disastrous impact on nature and ecology.
“Therefore, slag has a very good potential to become a suitable alternative material to these resources. It’s a new business avenue for us and we are going to make money out of waste, said Nair.”
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Presently, across the world around 33 MT of slag is generated and in India we have around 6-6.5 MT of slag at different sites of the three copper producers viz. Sterlite, Birla Copper and Hindustan Copper. The slag is highly stable and non-leachable in nature, said Nair.
He added, the utility of copper slag as an alternative material for other industrial ô sectoral applications has been vastly explored in the last one decade.
Some applications, wherein slag is already being used worldwide are in cement and concrete manufacturing, as a filling material, river embankment, ballast material, abrasives, pavement blocks, road and roofing construction, granules, glass, tiles making and others. Nair noted, the inclusion of copper slag has been approved as a filling material for the Chennai Metro Rail Project.
He noted, the Ministry of Environment and Forests, through its Hazadous Wastes Rules, 2008, excluded the pyrometallurgical operations. The company also said, the National Highways Authority of India (NHAI) has issued a policy letter for the usage of slag in road construction.
The company has now started supplying it to cement manufacturers in the South, including India Cements. So far, the company has despatched 700,000 tonne and has a stock of 3 million tonne.
Last year Sterlite’s Tuticorin unit generated revenue of around Rs 13,700 crore and this year it is likely to close the year with a turnover of around Rs 15,000 crore. Export contributes around 40 per cent of the total business.
The plant contributes around 3.5 per cent of the total gross state domestic product of Tamil Nadu (GSDP of Tamil Nadu which is Rs 4.36 lakh crore. The yearly contribution by the plant is around Rs 1,600 crore and Rs 750 crore towards customs duty. The unit has a 44 per cent market share in the primary copper market, said Nair.