Copper Mountain Mining has announced positive results from its 2020 feasibility study update for the Eva copper and gold project, 95km north-east of Mount Isa.
But company president and chief executive officer Gil Clausen says they will only proceed with development ‘in the right copper price environment’.
Total initial development capital for the Eva copper project is estimated to be about $587.5 million ($US382 million), which includes a contingency of $US42 million, while the after-tax net present value (NPV) would be $672 million ($US437 million).
The new model would see Eva produce 57 per cent more copper than was forecast in the 2018 feasibility study and the mine life has stretched out from 12 years to 15.
“The economics of the project have been improved with higher production, a longer mine life and lower operating costs,” Mr Clausen said.
“Eva Copper has the potential to add significant production and cash flow to our existing solid operating base.
“While we are and will continue to add value to Eva Copper, it should be noted that we will only move forward with development in the right copper price environment.”
Mineral reserve boosted 46 per cent
The Eva mineral reserve has increased 46 per cent compared to the 2018 estimate. It stands at 171 million tonnes grading 0.46 per cent copper and 0.05 g/t gold for a total of 1.7 billion pounds of copper and 260,000 ounces of gold.
There are seven pits that make up the Eva project’s mine plan. Little Eva is the primary pit and would be supplemented by progressively mining six satellite pit areas at Blackard, Scanlan, Turkey Creek, Bedford, Lady Clayre, and Ivy Ann.
The mine plan includes mining 551 million tonnes of ore and waste from seven deposits over a mine life of 15 years, with a waste to ore strip ratio of 2.2 to 1.
With an overall copper recovery of 87 per cent, the project’s total copper production is expected to be about 1.5 billion pounds of copper, while gold production would be 205,000 ounces based on a gold recovery of 78 per cent.
Metal production on an average annual basis would be 100 million pounds of copper and 13,650 ounces of gold. However, the first two years of mining are expected to produce approximately 128 million pounds of copper per year.
The processing flowsheet consists of a crushing, grinding, gravity separation and flotation to recover copper and gold in concentrate form.
Concentrate will be transported to the Mount Isa smelter, where Copper Mountain has a long-term contract with Glencore.
Copper Mountain said it had updated the flowsheet in its 2020 feasibility study by changing from a SAG mill and pebble crushing circuit to a secondary crusher and High-Pressure Grinding Rolls (HPGR) design, while the ball mill has also been upsized.