It is centred at Tuwu, around 120 kilometres from Hami, and is expected to become China's largest reserve of the mineral.

Jiang Chengsong, vice-minister of Land and Resources, announced the discovery Thursday.

Preliminary investigations by geological experts show the mines at Tuwu and Yandong hold a total copper reserve of 7.04 million tons, along with 18.7 million tons of associated silver.

When the investigation concluded at Linlong, Yamansu and Weiquan three to five years later, the total copper reserve in the eastern Tianshan Mountain area may exceed 10 million tons.

Jiang said the discovery of the copper zone will greatly fuel the country's economy.

According to Jiang, China spends between US$603.9 million to US$724.6 million each year on importing half a million tons of copper, 50 percent of China's requirement.

The cost is expected to increase soon as work progresses on an ambitious project to transmit electricity from western China to eastern China.

But with the new belt, China plans to establish a copper refinery, which can produce refined copper and copper products of 100,000 tons every year, and run for 50 years.

As copper mines need huge amounts of electricity, the rich coal mines in the area, which have been left unused through insufficient demand, can finally be exploited.

"We expect the electricity to be enough for not only our own use, but also the mines in neighboring countries, which suffer an electricity shortage," Jiang said.

International companies like Billiton and Rio Tinto have expressed the intention of developing the mines.

"We are seriously considering their proposals and are authorized to give some foreign companies the right to exploit Chinese mineral resources," said Hu Shanshun, a ministry official.

"Although we tend to decide the matter through international bidding, a final conclusion can only be reached after the ministry makes an agreement with other concerned government departments such as the State Development and Planning Commission."

(China Daily)