At a time when the mining industry is grappling with the challenge of environmental protection and conservation of natural resources, Tata Steel has adopted an organic method to tackle the problem of hexavalent chromium at its chromite mines at Sukinda in Jajpur district.
This method is being used to remove toxic hexavalent chromium from chromite concentrates.
To produce eco-friendly chromite concentrates, the company has made use of an alternative technology for converting toxic hexavalent chromium to non-toxic trivalent chromium at its Sukinda mines.
“The alternative technology has been developed by the steel maker in collaboration with the Central Leather Research Institute-Chennai. The technology seeks to reduce the hexavalent chromium to trace levels (less than 0.01 ppm) in concentrates by using an organic reductant known as Terminalia Chebula”, said a senior company official.
Since the chromium present in the hexavalent state is environmentally unfriendly, the organic method for removing hexavalent chromium from chromite concentrates is considered significant.
Apart from being environmentally friendly, the organic reduction method saves a huge quantity of water compared to conventional methods of treatment of the hexavalent chromium which requires huge amount of water (2000 litres per tonne).
Tata Steel claimed to be the pioneer in finding out a suitable method of treating hexavalent chromium by engaging Nagpur-based National Environmental Engineering Research Institute (NEERI). Based on its findings, an effluent treatment plant (ETP) was set up in 1993. It used pickle liquor as the reagent for treatment, which was the first of its kind in the country.
A pilot plant was established in 1998 to introduce automation in the dosing system and removal of suspended solids from the mine water. After a successful trial of the pilot plant, a full-fledged ETP with latest technologies of automatic dosing and suspended solid removal mechanism was established in 2002.
