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Highlights
- Viking Mines has achieved 76.0% combined tungsten recovery from gravity and flotation testwork at Linka.
- Premium concentrate grade of 56.9% WO₃ remains above the saleable threshold for scheelite concentrate.
- Flotation recovery increased to 33.89%, nearly double of the previous results.
- Metallurgical results continue to support a low-CAPEX processing pathway for the project.
- Maiden drilling at Linka remains scheduled to commence during the June 2026 quarter.
Viking Mines Limited (ASX:VKA) has reported further progress from metallurgical testwork at its Linka Tungsten Project in Nevada, USA, with follow-up flotation optimisation delivering a significant increase in tungsten recovery while maintaining a premium concentrate grade.
The latest results delivered a combined gravity-plus-flotation concentrate grading 56.9% WO₃ at a total recovery of 76.0%. The outcome represents a substantial improvement from the 59.8% recovery reported less than two weeks earlier and equates to a 1.27-times uplift in recovery.
The company noted that the latest phase of testing focused on improving flotation performance using gravity tails from the previous processing stages, with the results reinforcing the potential for a simplified processing flowsheet.
Flotation optimisation delivers recovery gains
The ongoing metallurgical program was conducted on a 10-kilogram subset of the Linka Pit sample LKMET0004. The work built on previously reported gravity and flotation test results and focused on optimising rougher and cleaner flotation circuits.
Key outcomes from the latest testing included:
- Combined gravity and flotation recovery increased to 76.0% from 59.8%.
- A premium concentrate grading 56.9% WO₃ was maintained.
- Gravity concentrate achieved 66.6% WO₃ at 42.16% recovery.
- Flotation concentrate achieved 48.2% WO₃ at 33.89% recovery.
- Rougher and cleaner flotation recovery increased to 33.89% from 17.1%.
The combined concentrate grade remains comfortably above the 50% WO₃ threshold generally regarded as saleable for scheelite concentrate.
According to the company, optimisation of flotation reagent regimes is continuing, with the aim of further increasing flotation recovery while maintaining concentrate quality.
Pursuing recovery above 80%
The latest metallurgical results mark a significant step forward in the development of the Linka processing flowsheet.
Viking is continuing to refine flotation conditions in an effort to lift overall recovery beyond 80% while retaining concentrate grades above the 50% WO₃ saleable benchmark. The company indicated that further market updates will be provided as optimisation work progresses.
The current results compare favourably with the company's most recent announcement, which reported a concentrate grade of 62.5% WO₃ at 59.8% recovery. While the grade has moderated slightly, the notable increase in recovery has lifted overall metal capture from the ore.
Low-CAPEX processing pathway gains support
The metallurgical program continues to support Viking's "Rapid-Start" development model, which prioritises physical separation methods over more complex chemical processing routes.
Refinement of the gravity circuit on the 10-kilogram sample improved the standalone gravity concentrate grade to 66.6% WO₃. The company noted that producing a premium scheelite concentrate through gravity separation alone provides a potential advantage for project development.
Viking believes this approach could support a simplified modular processing plant design, potentially reducing construction complexity and shortening development timelines compared with conventional processing facilities.
The latest metallurgical outcomes are being incorporated into the conceptual processing study currently underway with Mineral Technologies. The study is expected to contribute to ongoing refinement of capital expenditure estimates and plant design parameters.
Strategic relevance within the US tungsten market
The company highlighted the Linka Project's position in Nevada and its ability to generate high-grade tungsten concentrates through a low-CAPEX approach are becoming increasingly significant amid elevated tungsten prices.
Global ammonium paratungstate (APT) prices were reported at US$3,100 per metric tonne unit. As tungsten concentrates serve as feedstock for APT production, concentrate value is influenced by both prevailing APT prices and concentrate quality.
Higher-grade concentrates with lower levels of deleterious elements generally attract stronger payability. Producers of scheelite and wolframite concentrates typically receive between approximately 30% and 50% of the APT price, depending on concentrate specifications.
The company highlighted recent industry examples, including EQ Resources, which reported receiving US$1,189 per metric tonne unit for concentrates produced from its Mt Carbine operations during the March 2026 quarter.
Viking highlighted that the Linka Project is positioning itself as a domestic tungsten supply option as efforts continue to strengthen non-traditional supply chains for critical minerals.
Next phase of work underway
With gravity and flotation operating conditions now established, the metallurgical program is moving into optimisation and variability testing across four bulk samples collected from the Linka Project area.
Several workstreams are planned as part of the next development phase.
Flotation optimisation: The company will continue refining rougher and cleaner flotation conditions to maximise recovery while maintaining concentrate grades above the 50% WO₃ threshold. The target remains achieving recovery rates exceeding 80%.
Variability testing: Optimised processing conditions will be applied to the remaining bulk samples from the Conquest, Hillside and Stockpile areas to evaluate flowsheet performance across different material types.
Comminution studies: Detailed comminution testing will be undertaken on fresh samples to determine crushing and grinding energy requirements, along with ore abrasion characteristics. These findings are expected to support plant design and operating cost assessments.
Additional processing initiatives: Further gravity separation tests at coarser grind sizes are planned, while ore sorting studies will continue using a recently collected approximately 40-kilogram sample.
The conceptual processing study with Mineral Technologies is also progressing toward completion as the company works to finalise a modular development blueprint.
Geological and drilling programs: Beyond metallurgical studies, Viking is advancing geological interpretation of the project through completion of a three-dimensional geological model using recently digitised mapping and drillhole data.
The company also confirmed that permitting for drilling has been approved. Earthworks and drill site preparation are scheduled to begin during the June 2026 quarter, followed by commencement of the maiden drilling program at Linka.
Shares of VKA traded at AUD 0.011, at the time of writing on 10 June 2026.
