Archimedes Underground (Ruby Hill) PEA: $127M NPV, 23% IRR
i-80 Gold Corp.'s Archimedes Underground (Ruby Hill) in Eureka County, Nevada, USA has a Preliminary Economic Assessment (PEA) outlining an after-tax NPV of $127M, an after-tax IRR of 23%, and initial capital of $49M. The mine plan runs 10 years at about 101.9 koz Au per year.
i-80 Gold Corp.'s Archimedes Underground (Ruby Hill) has reported Preliminary Economic Assessment (PEA) results for the gold project in Eureka County, Nevada, USA. The study headlines an after-tax net present value of $127M at a 5% discount rate. It reflects i-80 Gold Corp.'s (IAU.TO) latest disclosed economics for the asset.
Economics. The after-tax NPV is $127M using a 5% discount rate. After-tax IRR is 23%. Initial capital expenditure is estimated at $49M. All-in sustaining costs are pegged at 1893 USD/oz. Economics are based on Base case $2,175/oz Au; alternative case $3,000/oz Au ($2,900/oz used on p.21).
Production and mine plan. The project envisions an underground operation. Life of mine is 10 years. Average annual production is approximately 101.9 koz Au. Average head grade is 7.0 g/t Au (grade processed). Metallurgical recovery averages 90%.
These figures are extracted from i-80 Gold Corp.'s technical disclosures and reflect the most recent PEA on file. Compare this project against other developers and producers in our project economics database, and always verify the numbers against the original technical report before making any investment decision.
Reserves & Resources
| Category | Tonnage | Grade | Contained |
|---|---|---|---|
| Indicated | — | 7.6 g/t Au | 436koz Au |
| Inferred | — | 7.3 g/t Au | 988koz Au |
Our Analysis
- IRR after-tax
- 23%
higher than 13% of 119 projects we track
- NPV after-tax
- $127M
higher than 20% of 169 projects we track
- Initial capex
- $49M
39% of NPV
costlier than 20% of 158 projects we track
- Mine life
- 10yrs
- Discount rate
- 5%
- Study price assumption
- Base case $2,175/oz Au; alternative case $3,000/oz Au ($2,900/oz used on p.21)
- Spot gold today
- $4,317.30/oz
Among the 119 gold projects we track, this one's 23% after-tax IRR ranks above just 13% of them, and its $127M after-tax NPV sits above only 20% of the 169 projects in our NPV set. That is the honest starting point: a bottom-quartile return on both measures, and one that clears the roughly 15% after-tax threshold developers typically need to attract project finance without much room to spare. For an investor, the rank matters more than the headline, because it says this asset competes for capital from the middle of a crowded field rather than the front.
The constraint that should dominate any read of this project is not the return but the scale of the company against the build. Initial capex is $49M, just 39% of NPV and lower than 80% of the 158 gold projects we track, so the capital intensity is genuinely light. Set against a US$1.57B market cap, the build is small: this is a diversified company with nine projects in our coverage, and it can fund a $49M construction programme without the dilution or financing gymnastics that sink single-asset developers. The funding risk here is close to negligible, which is precisely why the modest IRR is tolerable rather than disqualifying.
Two caveats temper that. This is a PEA, scoping-level work that may rest on inferred resources and carries a capital estimate with a plus or minus 50% band, so neither the $49M nor the returns should be treated as fixed. And the study's base case of $2,175/oz sits well below today's $4,317.30/oz spot, meaning the economics as published are conservative against the current market, with an alternative $3,000/oz case already sketched. The question that decides this project is whether a bottom-quartile return can be lifted by the price deck the market is actually paying, or whether the rank reflects something structural in the orebody.
Our take, benchmarked against the project economics in the Mining Stocks database. Figures are estimates drawn from company technical reports — not investment advice; always verify against the source filing.