The National Green Tribunal (NGT)  on Saturday set aside the Tamil Nadu government order for closure of the copper unit at Tuticorin, which was at the centre of massive protests over alleged pollution, saying it was "non sustainable" and "unjustified".

In May, the state government had ordered permanent closure of the company's copper unit after 13 people, among protesters, demanding its shutdown on environmental concerns, were killed in police firing. Sterlite Copper had challenged the order in the NGT.

"It is a very positive move. We welcome the order. Due to the closure the import and prices of copper had gone up," Sanjeev Ranjan, ICA India managing director said.

The closure of the plant had adversely impacted copper consuming industries like consumer goods, electrical and electronics, automobile, and players were bound to import the metal, he said.

ICA believes reopening of the smelter unit will bring relief to the downstream and ancillary industry, the MD added.

Due to the closure, domestic chemical and fertilisers industry was also impacted, he said.

Sterlite Copper's 4,00,000 tonne per annum plant in Tuticorin met over 30 per cent of the of India's copper demand. It also produced sulphuric and phosphoric acids as a by-product which are key raw material for manufacturing of fertiliser, the company said.

It also said that "due to the shutdown in the last six months... import of the metal (copper) has seen a surge. While premium on copper has gone up by 10-15 per cent, the import of the metal has shot up 2.5 times to nearly 30,000 tonne per month".

The closure has led to a spike in prices of phosphoric and sulphuric acids, adversely affecting the downstream chemical and fertilisers industry, it noted.

"The plant met 80-90 per cent of demand for sulphuric acid in the country and 15 per cent of the phosphoric acid demand. The closure of our plant has led to a sharp surge in demand, thereby driving up prices," its CEO P Ramnath said.

In the last six months, prices of sulphuric acid have shot up from Rs 3,000/tonne to Rs 12,000/tonne, and a tonne of phosphoric acid costs Rs 53,000 as compared to Rs 43,000 a tonne six month earlier, a rise of 23 per cent, he said.