Tungsten Mining NL has updated the Mineral Resource Estimate for its Watershed Tungsten Project, increasing contained tungsten by 8% through a lower cut-off grade reflecting strong market prices.
- Cut-off grade lowered from 0.05% to 0.04% WO3
- Total resource now 69.7 million tonnes at 0.109% WO3
- Contained tungsten rises to 76,000 tonnes, up 8%
- Resource reported under JORC 2012 with Multiple Indicator Kriging
- Open-pit mining supported by granted leases and environmental approvals
Resource Upgrade Reflects Strong Tungsten Prices
Tungsten Mining NL (ASX:TGN) has boosted the reported size of its Watershed Tungsten Project resource by 8%, now totalling 69.7 million tonnes at an average grade of 0.109% WO3, containing 76,000 tonnes of tungsten trioxide. This increase follows a strategic reduction in the reporting cut-off grade from 0.05% to 0.04% WO3, a move designed to capture more of the deposit’s economic potential amid a materially stronger global tungsten price environment.
Chairman Gary Lyons highlighted the significance of the update, stating that the lower cut-off grade directly reflects the tightening tungsten market and the inherent quality of the Watershed deposit. This positions the company well for advancing the project’s development as global supply constraints persist.
Robust Data and Modelling Underpin the Estimate
The updated Mineral Resource Estimate (MRE) complies with the 2012 JORC Code and employs Multiple Indicator Kriging (MIK) modelling via H&S Consultants Pty Ltd, reflecting a sophisticated approach to handling the deposit’s complex geology and grade variability. The resource extends approximately 1.2 kilometres along strike, with widths between 250 and 500 metres and a vertical depth of up to 450 metres.
Supporting the estimate is an extensive drilling database comprising 350 drill holes and costeans, totalling over 55,000 metres, including 48,558 metres of diamond core. Historical and recent drilling campaigns have been rigorously validated with comprehensive quality control protocols, including umpire assaying, reference standards, and duplicate sampling, ensuring confidence in the data quality.
Project Geology and Mining Outlook
Watershed hosts scheelite mineralisation predominantly in quartz-scheelite vein swarms and disseminated forms within calc-silicate altered rocks. The scheelite is notable for being molybdenum-free, a key advantage as molybdenum attracts penalties from smelters. The deposit lies within granted mining leases and holds an Environmental Authority permitting open-pit development, with geotechnical studies supporting slope designs and mining parameters.
The company plans to mine the deposit via conventional open-pit methods, with mining dilution and ore loss assumptions incorporated into the resource classification. Metallurgical testwork confirms the amenability of the ore to established processing techniques including dry crushing, ore sorting, gravity separation, and flotation, with ongoing validation underway.
Next Steps and Exploration Potential
The Watershed deposit remains open at depth and along strike, with Tungsten Mining planning a 15,000-metre reverse circulation drilling campaign to infill and extend the resource. This drilling aims to tighten drill spacing to 20–30 metres and test the continuity of mineralisation, supporting future resource upgrades and mine planning.
While the updated resource is globally robust, some local estimation uncertainty remains due to geological complexity and drill spacing. No production data exists for reconciliation, as the project is yet to enter mining. The company’s ongoing efforts at Watershed, alongside its broader portfolio, underscore its ambition to become a significant player in the global tungsten market amid rising demand and constrained supply.
Bottom Line?
The resource upgrade at Watershed underscores Tungsten Mining’s strategic response to a tightening tungsten market, but upcoming drilling and metallurgical results will be critical to unlocking the deposit’s full value.
Questions in the middle?
- How will the 2026 drilling campaign impact resource confidence and grade distribution at Watershed?
- What are the timelines and capital requirements for advancing Watershed toward production?
- How might evolving tungsten market dynamics influence cut-off grades and project economics going forward?