Northern Vertex Mining Corp.'s preliminary economic assessment at its Moss gold-silver mine in Arizona pegged a posttax net present value, discounted at 5%, of US$93.0 million, a 52.5% internal rate of return and a 27-month payback period.

The study uses a base case gold price of US$1,250 per ounce and a silver price of US$20 per ounce.

Gold production from the project is estimated at 313,150 troy ounces during its 10-year life, Northern Vertex said Oct. 10.

The study estimated capital costs of US$61.6 million and operating costs of US$190 million. The capital costs include US$37.5 million in sunk costs for the construction of the mine's second phase.

The gold equivalent cash cost is estimated at US$527 per troy ounce, with the all-in sustaining cost forecast at US$603 per troy ounce.

The preliminary economic assessment is based on a measured and indicated mineral resource, estimated in October 2014, of 15.5 million tonnes at 0.76 g/t of gold and 9.3 g/t of silver, using a 0.25 g/t gold cutoff grade. The estimate also contains 2.18 million tonnes in the inferred category at 0.55 g/t of gold and 5.6 g/t of silver using the same cutoff grade.

Northern Vertex received the final permit to start commercial production at its Moss project in April.