The playbook — molybdenum · October 15, 2026
Erdene puts numbers on its Mongolian molybdenum mountain
A first economic study pegs Zuun Mod at a US$745M base-case NPV — built on a large, low-grade porphyry and a lot of inferred rock.
Erdene Resource Development, the company that poured first gold at its Bayan Khundii mine in Mongolia just over a year ago, has now put dollar figures on its other big asset. On October 14 it released a Preliminary Economic Assessment — an early, rough-cut study of whether a mine makes money — for Zuun Mod, a molybdenum-copper deposit in southwestern Mongolia. The headline number: a base-case net present value of US$745 million, with a spot-price case of US$2.0 billion. Molybdenum is a steel-hardening metal; copper is the byproduct here.
This is not a drill-result release, so there are no fresh intercepts to parse. What matters instead is scale and grade. Zuun Mod holds 407 million tonnes of measured-and-indicated resource plus 596 million tonnes of inferred material, grading roughly 0.04 to 0.05% molybdenum — a genuinely large endowment, but a lean one. The plant would feed on rock averaging 0.041% Mo and 0.058% Cu, so the whole case rests on moving enormous tonnage cheaply, helped by a low 1.3-to-1 strip ratio (1.3 tonnes of waste dug for every tonne of ore). Akerley, who ran the Bayan Khundii build for about US$114–115 million and within roughly 10% of budget, is the operator behind this. The market noticed: Erdene rose about 9% over three months while the base-metals peer index fell 3.2% — a 12.5-point spread that looks company-specific, though the stock has given back part of a mid-period surge to settle near C$5.55.
Now the honest part. The base case runs on US$25/lb molybdenum — above typical long-run prices — and the US$2.0 billion spot case assumes US$33/lb. About 74% of the forecast plant feed, and even 16% of the feed during payback, comes from Inferred resources, the most speculative category, which by definition cannot carry demonstrated economic viability. The capital estimate is AACE Class 5, meaning it could land anywhere from 20–50% under to 30–100% over, with no contractor tenders obtained yet. The deposit sits 280 kilometres from a railhead, in a jurisdiction modelling proposed-but-unenacted copper tax and royalty rules. The company says the NI 43-101 technical report will be filed within 45 days of the October 14 release, drilling to upgrade the resource and test copper targets is set to begin in late October, and partner discussions continue with no timing stated.