Great Western Mining Corp. Plc's JORC-compliant scoping study over its M2 copper-gold prospect in Nevada pegged a base case mine life of 13 years using current mineral resources.

The company recently estimated indicated and inferred resources at M2 of 17 million tonnes at 0.525% copper containing 89,195 tonnes, using a 0.2% cutoff.

The mineral resources would be exploited by open pit mining, heap leaching, solvent extraction and electrowinning at the mine site.

The minable resources stand at 16.1 million tonnes grading 0.48% copper in two separate open pit mines, the company said Oct. 10.

At a copper price of US$3.00 per pound, the base case net present value, discounted at 8%, was estimated at negative US$36.7 million, a 1% internal rate of return and cash flows of US$12.6 million.

The net present value, discounted at 8%, will increase to US$36.4 million at a copper price of US$4.00 per pound, with a 14% internal rate of return and cash flows of US$164 million.

The scoping study also assumes several scenarios taking into account various additional exploration targets that may lead to the mine life being extended to up to 23 years. The company pointed out that every case examined by the study produces positive pretax margins at current copper prices.