Archimedes Underground PEA: $127M NPV, 23% IRR
i-80 Gold Corp.'s Archimedes Underground in Eureka County, Nevada, USA (Ruby Hill) 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 has reported Preliminary Economic Assessment (PEA) results for the gold project in Eureka County, Nevada, USA (Ruby Hill). 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 $2,175/oz gold (base case); also shown at $2,900/oz and $3,000/oz.
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. 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 |
| Inferred | — | 7.3 g/t Au | 988koz |
Our Analysis
- IRR after-tax
- 23%
higher than 14% of 105 projects we track
- NPV after-tax
- $127M
higher than 18% of 141 projects we track
- Initial capex
- $49M
39% of NPV
costlier than 22% of 139 projects we track
- Mine life
- 10yrs
- Discount rate
- 5%
- Study price assumption
- $2,175/oz gold (base case); also shown at $2,900/oz and $3,000/oz
- Spot gold today
- $4,658.20/oz
Ruby Hill sits in the bottom quartile of the gold projects we track: its 23% after-tax IRR ranks higher than just 14% of 105 peers, and its $127M NPV ranks higher than 18% of 141. That rank is worth exactly what it sounds like, a modest, single-asset return profile that clears the roughly 15% project-finance hurdle but offers no margin for operational slip. The 5% discount rate used to derive the NPV sits at the low end of reporting convention, which flatters the headline figure; at a more typical rate, the NPV would compress further. Investors should read this as a solid, unexciting project, not a standout.
The constraint that matters most is not geology or price, it is capital discipline, and here the project is genuinely small. Initial capex of $49M is 39% of NPV and lower than 78% of the 139 gold projects we track, and the build cost is small relative to the company's US$1.69B market cap. That combination removes the usual funding risk: this is not a company stretching to finance a build worth several times its equity. The company holds a diversified portfolio of 9 tracked projects, so Ruby Hill is one option among many, not a bet-the-company development. The PEA stage, however, tempers the confidence: scoping-level estimates carry a plus or minus 50% capital band, and the 10-year mine life is short.
The price deck is the swing factor. The base case assumes $2,175/oz gold, but the current spot price of $4,658.20/oz is more than double that, and the study also shows cases at $2,900/oz and $3,000/oz. At spot, returns would be far higher than the 23% IRR suggests, and the project's low capital intensity means that upside flows straight to the bottom line. The question that decides whether Ruby Hill works is simple: does the company commit to a modest build in a mining-friendly Nevada jurisdiction, or does it let a capital-light, permitted asset sit undeveloped while the portfolio's larger options compete for the same dollars?
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.