Nalco explores use of non-explosives for bauxite mining

Shaken by the recent naxalite attack on its mines at Panchpatmali hill in Koraput district of Orissa, the public sector aluminium major, National Aluminium Company (Nalco) is exploring the possibility of adopting non-explosive technology for mining bauxite.

“We are looking at available technologies in this regard”, CR Pradhan, chairman cum managing director of Nalco told Business Standard.

The Red rebels had raided the Nalco mines, having the largest deposits of bauxite in Asia, on April 12 with an aim to loot the explosives stored in the magazine house there. Though they failed in their bid to take away the explosives, they killed 10 jawans of Central Industrial Security Force (CISF) deployed to guard the magazine house and held about 100 mining workers of the company hostage for over ten hours before beating a retreat.

Nalco mines being located in the naxal infested areas, the company in the past had looked at various options to minimize the use of explosives in bauxite mining to reduce the risk of attacks by ultras keen on laying their hands on its explosive store. In the process, the company had weighed the possibility of using alternative technologies.

One such option was to use high end dozers, excavators and other earth moving machines to remove the overburden to reach the bauxite layer. But considering the hard rocky type overburden in the area, this method was found to be prohibitively costly.

Similarly, the company ran a pilot project between 2006 and 2008 on use of SMS technology developed by IBP Ltd, for mining of bauxite. The site mixed slurry (SMS) explosives, as the name suggests, are manufactured on site in a specially designed truck by carrying non-explosive ingredients in separate chambers, mixing them in tailor-made proportions and pumping them in liquid form directly in to bore holes. The poured mixture acquires the characteristics of an explosive within about ten minutes of pumping and solidifies slowly to the shape of the bore hole, which is then blasted using small quantity of booster explosives.

The system eliminated the need for packaging, inventory, storage and handling of various types of explosives and thus lowered risk of attacks by the ultras on the look out of looting explosive dumps.

But unfortunately, sources said, IBP left the project mid-way leaving the company no option but to rely on its traditional way of using explosives for mining.

But the recent naxal attack has again spurred the company to look for new technologies, both within the country and abroad to minimise or do away with the use of explosives. “The Coal India is currently using technologies which does not require explosives”, Pradhan said, “but these technologies may not be suitable for bauxite mining, particularly in the kind of topography that we have at Panchpatmali”.

“We are now taking a look at latest non-explosive technologies available in Australia and South Africa which can be adopted for bauxite mining and to our environ”, the Nalco CMD said and added that if required the company may appoint a consultant to help it in this endeavour. Finding such technology makes a lot of sense for the company as it is now spends around Rs 2 crore per month to guards explosives worth Rs 7 lakh in its magazine store at the mines.