Currently the mine plan is for an open pit at Kun-Manie, but by going underground at the Flangovy target and below the planned Kubuk pit Amur expects to increase the tonnage available by a quarter to 90.2mln tonnes.
A 50/50 open pit/underground operation would potentially capable of supporting a six million tonne per annum capacity project for a 15 year period, Amur estimates, compared to 11 years previously.
Underground production is estimated to be 44.1 mln tonnes of ore averaging 0.55% nickel and 0.16% copper.
Amur estimates underlying profits [EBITDA] using a 50/50 of open pit and underground operation would be about US$1.4 bln, a 19% increase over the life of mine.
Flangovy is targeted for in-fill drilling during the next field campaign with a target of 26.3mln tonne, while Kubuk is holds 17.8 mln tonnes to upgrade the resource.
Robin Young, Amur Minerals’s chief executive, said the latest analysis was another step forward in the final design bases of the proposed Kun-Manie operation.
“The ability to reduce the pit size at Maly Kurumkon / Flangovy while simultaneously expanding the reserve through economic underground extraction of uneconomic open pit reserves has provided additional upside to the project economics.
“We can now realistically establish a long term mine life thereby sustaining a large scale operation at six million tonnes per year subject to completion of in-fill drilling within two deposits."
The next step will be to determine whether to build its own smelter, which will depend if the final product as a low grade matte, a high grade matte, or final cathode product.