The new mine life is estimated at 21 years, including three years of processing stockpiled ore. Total production is expected to be 2 billion pounds of copper, 978,000 ounces of gold and 6.7Moz of silver.

Copper Mountain estimates the new mine plan increases the company's after-tax net present value (NPV) by more than 60% to $1 billion due to higher annual production and lower costs.

"This mill expansion study builds upon the growth projects that are already underway and illustrates the immense potential that the Copper Mountain mine provides. In two years we have more than doubled the mine life, grown the mine's productive capacity, increased net asset value and significantly decreased cash costs," said Copper Mountain president and CEO Gil Clausen.

The proposed expansion includes installation of a HPGR (high pressure grinding roll) circuit, a fourth ball mill, regrind circuit, Vertimill, additional rougher and cleaner flotation circuits, and electrical system upgrades.

Total life of mine expansionary capital, including the capital for the 45,000tpd mill expansion which is underway 2021 and the integration of New Ingerbelle, is estimated to be $204 million.

The 45,000tpd expansion will add a third ball mill to the current conventional two-stage crushing, SAG, pebble crusher, ball milling and sulphide flotation circuit design supporting a 40,000tpd throughput rate.

Shares in Copper Mountain Mining are trading at C$1.51, valuing the company at $313 million.