Watershed testwork opens path to premium tungsten concentrate

Watershed produces saleable tungsten concentrate

The most important result from Tungsten Mining NL (ASX:TGN, OTCQB:TGNMF) is not simply a high assay, but the confirmation that its Watershed project can produce customer-grade tungsten concentrate through a conventional processing route. Testwork produced concentrates grading up to 65.9% WO3, with two marketing samples achieving grades of 53.8% and 65.9% WO3 at recoveries between 60% and 70%.

The company says those products meet typical customer saleable specifications and contain low levels of impurities. The results were generated from composite samples sourced from diamond drill core, selected across weathering profiles and geological domains intended to provide coverage of early mine-plan areas.

Ore sorting anchors the DFS flowsheet

The proposed processing circuit starts with X-ray transmission ore sorting at TOMRA, followed by primary and secondary milling, gravity separation, sulphide flotation and final cleaning. On the reported testwork, ore sorting rejected up to 88% of the feed mass while retaining 82% of the WO3, upgrading a 0.25% WO3 feed to a pre-concentrate above 4%.

That coarse-grained response matters to the design. Tungsten Mining says the scheelite mineralisation can be upgraded with relatively limited grinding, allowing coarse waste rejection before wet processing and reducing the size of the proposed beneficiation circuit. The initial plant is intended to produce a concentrate above 50% WO3, while additional equipment could later support production above 65% WO3 and improve recovery.

Bulk sample and offtake discussions move forward

Commercial engagement is now the next test. Samples have been dispatched to potential downstream partners across Asia, Europe and North America, with discussions on indicative commercial terms progressing in parallel. Tungsten Mining is targeting binding offtake agreements around completion of the DFS and a final investment decision in the fourth quarter of 2026.

A larger 134-tonne bulk sample is being processed to generate more substantial volumes for customer evaluation. The crushed material is being X-ray sorted in Sydney, while the finer fraction and sorter accepts are undergoing pilot-scale gravity and flotation work at Nagrom in Perth. The company also reported a 64.3% WO3 result from a 16.9-kilogram rock-chip sample taken from the bulk-sample area, but flagged that the selective grab sample is not representative of the deposit or future production.

DFS timing remains the next project gate

The Definitive Feasibility Study remains targeted for completion in October 2026, ahead of the planned Q4 2026 investment decision. The metallurgical results settle the proposed process route at the study level, but they do not establish that the reported grades, recoveries or product specifications will be achieved at commercial scale.

Nor is there an offtake contract yet. The company expressly cautioned that commercial terms may not be acceptable, or that binding agreements may not be concluded at all. The pilot-scale bulk work, customer testing and the terms attached to any future offtake arrangements will therefore determine whether the laboratory result can become a bankable development proposition.