Guardian’s $660M Nevada tungsten mine: PFS economics and risk lens for engineers
Reviewed by Joe Ashwell
First reported on MINING.com
30 Second Briefing
Guardian Metal Resources may move directly from prefeasibility to construction at its Pilot Mountain tungsten project in western Nevada, after a new PFS returned a post-tax NPV8 of $660.3 million, 59.6% IRR and a one-year payback on $288.7 million in capex. The plan envisages an eight-year open-pit operation mining 11.8 million tonnes of probable reserves at 0.171% WO3, feeding a 4,000 t/d mill to produce 15,916 tonnes of 60% WO3 concentrate plus 2.1 million oz silver. Guardian targets adjusted operating costs of $54,622 per tonne WO3 (net of by-products), is filing its mine plan with the BLM next month and aims for all concentrate to be processed in the US.
Technical Brief
- Initial capital of $288.7 million includes $39.1 million contingency and $34.3 million preproduction mining.
- Sustaining capital is estimated at $33.9 million, with mine closure and reclamation costs of $22.3 million.
- Open pits will mine Desert Scheelite and Garnet deposits, spaced roughly 2 km apart in western Nevada.
- Probable reserves: 11.8 Mt at 0.171% WO3, 9.28 g/t Ag and 0.28% Zn, yielding 20,275 t WO3.
- Planned flowsheet uses truck-and-loader mining, followed by crushing, grinding and flotation to produce 60% WO3 concentrate.
- Base-case economics assume a WO3 price of $197,300/t, 35% below June 12 APT spot.
- At June 12 APT spot, after-tax NPV increases to $1.4 billion and IRR to 102%, with six‑month payback.
- Guardian received a $6.2 million US Defense Production Act award, supporting PFS completion and de-risking funding.
- Mine plan submission to the US Bureau of Land Management is scheduled next month, with a 12‑month Record of Decision allowance.
- Tempiute (former Emerson mine) offers potential satellite feed or tailings reprocessing, supported by existing 3,000 kW substation infrastructure.
Our Take
Guardian Metal Resources’ parallel build-out at the Tempiute tungsten project in Nevada, including a more than 375% claim expansion reported in May 2026, suggests Pilot Mountain and Tempiute are being positioned as a multi-asset critical minerals platform rather than a single-mine story.
Within our mining database, tungsten appears far less frequently than gold or copper, so a US-based project like Pilot Mountain with an 8-year reserve-backed mine life stands out as one of the relatively few advanced-stage tungsten assets in a jurisdiction outside China, which already supplies about four-fifths of global mined tungsten.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
Related Articles
Related Industries & Products
Mining
Geotechnical software solutions for mining operations including CMRR analysis, hydrogeological testing, and data management.
Construction
Quality control software for construction companies with material testing, batch tracking, and compliance management.
CMRR-io
Streamline coal mine roof stability assessments with our cloud-based CMRR software featuring automated calculations, multi-scenario analysis, and collaborative workflows.
HYDROGEO-io
Comprehensive hydrogeological testing platform for managing, analysing, and reporting on packer tests, lugeon values, and hydraulic conductivity assessments.
GEODB-io
Centralised geotechnical data management solution for storing, accessing, and analysing all your site investigation and material testing data.