Refining and copper rod manufacturing operations are unaffected, the company said.

Sterlite, a subsidiary of commodities conglomerate Vedanta Resources, signed off a $717 million investment to double the 400,000 tonne smelting capacity at Tuticorin in Tamil Nadu, India, a move that would make it the world's second-largest single smelter.

“Smelting operations at Tuticorin will be closed for approximately 15 days as part of a maintenance shutdown. This activity was earlier scheduled for the month of April 2018.” The company stated.

Yet protesters allege the plant has discharged harmful chemicals into the local environment, the Times of India reported.

Metal Bulletin's copper concentrate treatment and refining charge index dropped to $68.60 per tonne / 6/6.86 cents per lb on March 15; traders are maintaining aggressive bids for spot parcels in expectation of a tight market in the third and fourth quarters.