The PFS anticipates average annual gold production of 116,000oz gold in years one through eight, and 205,000oz silver in years four through eight over an initial eight-year mine life, at all-in sustaining costs of $657 per ounce.
The project would yield an after tax net present value of $241.5 million at a 5% discount rate and an internal rate of return of 27.8% at a $1,400 gold price and a $17.11 silver price following an initial capital expenditure of US$194 million.
"We are very pleased with this first iteration of this PFS which is needed now so that we can start the permitting process," president and CEO Jonathan Awde said.
"We have many opportunities to improve on the base case which includes the goal to add mine life by potentially upgrading more of the existing resources within the PFS area and exploiting the other nearby deposits we have discovered. We also have some great opportunities to improve economics via trade-off studies which could reduce capital costs or improve recoveries.
"We will be looking to quantify these opportunities through further economic studies in the first half of 2020."
The project would exploit a proven and probable mineral reserve of reserve of 47.3Mt grading 0.82 grams per tonne gold and 4.70g/t silver at Pinion containing 1.248 million ounces of gold and 2.7Moz silver.
Gold Standard now plans to finalise permit applications for the project with the US Bureau of Land Management for an environmental impact statement. Drilling will also continue with the aim of converting inferred resources to the measured and indicated categories for addition to the mine plan at Dark Star, Pinion and the Jasperoid Wash deposit. Trade-off studies will also be initiated to optimise economics.
The PFS considers near surface open pit mining of 47.3 million tonnes of oxide and transitional ore at a processing rate of 5.9Mt per year. Ore will be processed either run of mine or through a high-pressure grind roll crusher and stacked on a heap leach pad and leached using a sodium cyanide solution. Pregnant solution will be processed through a dual train carbon-in-column plant, with gold and silver captured in an ADR plant.
Dark Star is comprised of Carlin-style, sediment-hosted gold mineralisation, while Pinion comprises Carlin-style, sediment-hosted gold and silver mineralisation. Mineralisation is almost completely oxidized to depths of about 330m. Dark Star contains small zones of unoxidised and transitional material above this level.
Shares in Gold Standard Ventures (TSX:GSV) opened down almost 7% at C$1.23 valuing the company at $366 million.