i-80 Gold Corp. has officially published results from a preliminary economic assessment (PEA) for the Granite Greek Underground Project.
In case you weren’t aware, Granite Creek Underground happens to be the first property within company’s pipeline of assets to be redeveloped. Currently ramping up to full production, the project is situated at the intersection of a highly prolific Battle Mountain-Eureka and Getchell gold trends in northern Nevada, United States.
Before we dig into the published results, though, we ought to mention that resource employed in this PEA does not include drilling conducted during 2023 and 2024. Beyond that, underground water management in the 2025 mine plan is also not reflected in the given study.
Anyway, talk about the study on a slightly deeper level, it revealed a high-grade underground gold mine with a life of mine (LOM) of approximately 8 years. This it did along with an average annual gold production of approximately 60,000 ounces, following production ramp up.
Next up, the study revealed estimated LOM cash costs of $1,366 per ounce and all-in-sustaining costs of $1,597 per ounce. It also published an updated mineral resource estimate, which showed a measured and indicated gold mineral resource of 261,000 ounces at 10.5 grams per tonne (“g/t”) and an inferred gold mineral resource of 326,000 ounces at 13.0 g/t.
Another detail worth a mention here is rooted in how, based on exploration work conducted to-date, Granite Creek Underground has significant potential for resource expansion. We also get to say so because the site is actually located only 10 kilometers from the prolific Turquoise Ridge Complex within Nevada Gold Mines’ joint venture, a hotbed which currently hosts approximately 20 million ounces of gold.
As a result, an extensive drill program is planned for the coming years to test this system at depth and to the north.
Turning our attention towards project economics, they relay that, based on a $2,175/oz gold price, the Project’s undiscounted after-tax cash flows settle around $197 million with an after-tax net present value of $155 million, assuming a 5% discount rate.
Based on a spot gold price of $2,900/oz, the Project’s undiscounted after-tax cash flows settled around a total of $420 million, with an after-tax NPV value at $344 million. This was again assuming a 5% discount rate. All in all, LOM development and sustaining capital is estimated at $105 million.
Beyond that, the report offers details on the site’s primary mining method, which is underhand drift and fill.
Moving on, it informs readers on the fact that, over the next three years through to the end of 2027, refractory material mined is expected to be processed at a third-party autoclave facility. This should orchestrate approximately 30% lower payability on gold produced until i-80 Gold’s Lone Tree facility is commissioned as anticipated in 2028.
The report also touches upon the fact that site’s overall average gold grade processed of 11.6 g/t comes around an average gold recovery of 78%, utilizing oxide processing, acidic pressure oxidation, and alkaline pressure oxidation selected based on characteristics of the mineralized material.
This average LOM recovery includes the 58% payability factor for years 2025 – 2027. However, once the company’s autoclave facility is refurbished, process recovery rates are expected to rise to approximately 92%, significantly increasing production, lowering costs, and improving cash flows from the project.
Finally, our last piece of highlight is reflected in a projection that tips Granite Creek to recover gold ounces of between 20,000 and 30,000 ounces during 2025.
“Our exploration results at Granite Creek Underground to-date suggest significant potential for resource growth and expansion. As a result, an extensive drill program is planned in the coming years to realize that potential. The PEA also demonstrates that once our Lone Tree autoclave is refurbished as anticipated in 2028, production and cash flow are expected to increase materially,” said Richard Young, Chief Executive Officer at i-80 Gold Corp.
