AUS
NZ
UK
CA
USA
IND
Highlights
- Viking Mines has achieved 62.5% WO₃ concentrate at 59.8% recovery through combined gravity and flotation processing.
- Gravity circuit refinement delivered 66.6% WO₃ concentrate with 42.7% recovery on a 10 kg sample.
- Flotation stages contribute 54.3% WO₃ concentrate at 17.1% recovery from gravity tails.
- Study work supports a simplified modular processing pathway under the Rapid-Start model.
- Metallurgical program advances into optimisation, variability testing and flowsheet validation stages.
Viking Mines Limited (ASX:VKA) (OTC:VKALF) has reported a key step forward at its Linka Tungsten Project in Nevada, USA. The update follows advanced metallurgical testwork that integrates gravity with cleaner flotation circuit testwork.
The latest program, conducted on a larger 10 kg sample, shows a notable shift in both recovery and concentrate grade outcomes compared with earlier phase results. By combining refined gravity separation with first-pass rougher and cleaner flotation, the company has delivered a higher-grade scheelite concentrate while also lifting overall recovery levels.
Metallurgical Work Advances at Linka
The follow-up metallurgical testwork on a 10 kg subset of the Linka Pit sample LKMET0004 has expanded earlier gravity-only results by introducing a first-pass rougher and cleaner flotation circuit on gravity tails.
- The feed sample, grading 1.2% WO₃, was processed through an optimised gravity stage that produced a standalone gravity concentrate grading 66.6% WO₃, compared with 63.6% previously, while maintaining 42.7% recovery versus 42.4% earlier.
- The flotation stages delivered a 54.3% WO₃ concentrate at 17.1% recovery, establishing the basis for combining gravity and flotation streams into a unified flowsheet for further optimisation.
Combined Circuit Performance Lifted
- The integration of cleaner flotation on gravity tails has lifted overall performance to a combined concentrate grade of 62.5% WO₃ at 59.8% recovery. This compares with earlier results of 56.4% WO₃ at 46.0% recovery.
- The combined output remains above the >50% WO₃ saleable threshold. Gravity contributes 66.6% WO₃ at 42.7% recovery, while flotation adds 54.3% WO₃ at 17.1% recovery.
Reagent optimisation is underway to refine cleaner stages, with the aim of improving recovery and grade. Further performance variability is being assessed through ongoing testwork.
Processing Pathway and Plant Design Approach
The results support the “Rapid-Start” model focused on low-cost physical separation. Gravity circuit refinement at 10 kg scale confirms production of high-grade scheelite concentrate through gravity alone, supporting a simplified modular plant design. This approach offers flexibility in permitting and construction compared with conventional processing routes. Outcomes are being incorporated into a conceptual processing study with Mineral Technologies to refine plant design and capital estimates. The integrated gravity and flotation flowsheet provides a scalable foundation for development planning at Linka.
Strategic Positioning in US Supply Chain
With APT prices at USD 3,050/mtu, Linka sits within a supply environment focused on domestic tungsten sourcing. High-grade concentrate production through a low-capex model in Nevada supports its positioning in the US supply chain. As the US Department of War and domestic manufacturers seek secure “NATO-grade” tungsten outside traditional channels, the project is being assessed as a potential onshore supply option. Metallurgical results contribute to evaluating its role in critical minerals supply frameworks.
Next Steps in Testwork Program
The programme is moving into optimisation and variability testing across four bulk samples. Work includes flotation reagent optimisation, variability testing on Conquest, Hillside and Stockpile samples, comminution testing, and continued gravity separation at coarser grind sizes. Ore sorting trials are planned on a ~40 kg sample. The conceptual processing study with Mineral Technologies is progressing, alongside completion of a 3D geological model. Maiden drilling at Linka remains scheduled for the June 2026 quarter following approval.
Shares of VKA traded at AUD 0.011, at the time of writing on 28 May 2026.
