Evolution Mining has reported a negative all-in sustaining cost at the Glencore-operated Ernest Henry copper-gold mine in Queensland.
The company declared an AISC of negative $710 per ounce on the same day Newcrest reported its lowest ever AISC at its Cadia copper-gold mine of negative $US6 ($7.82) per ounce.
This was guided by Ernest Henry’s negative operating costs due to revenue generated from copper and silver by-products.
It builds on the mine’s achievement of negative $515 per ounce AISC during the September quarter.
Evolution produced 4972 tonnes of copper per tonne during the December quarter, slightly less than the 5040 tonnes delivered in the previous period.
It has a 30 per cent interest in copper production at Ernest Henry, with the operator Glencore holding the remaining 70 per cent.
Evolution’s progress in completing an underground feasibility study at the Cowal gold mine in New South Wales is also on schedule.
This is aimed to increase Cowal’s annual production to more than 350,000 ounces.
The board of Evolution has approved the ramp up of development of the Galway decline, paving the way for mobilisation in the March quarter.
Drilling has proven the potential for further growth in the Cowal underground mine, according to Evolution.
At the Mungari gold mine in Western Australia, production slipped from 35,370 ounces in the September quarter to 30,463 ounces in the December period due to a planned mill shutdown.
The mine also endured a minor seismic event in the White Foil open pit, although operations have resumed since.
Mungari’s AISC jumped from $1115 per ounce to $1402 per ounce over the same period.