Viking Mines Ltd (ASX:VKA) has achieved a significant improvement in metallurgical recovery at its Linka Tungsten Project in Nevada, USA, with combined gravity and flotation testwork delivering a 76.0% recovery rate while maintaining a concentrate grade of 56.9% WO₃. The result exceeds the company's previously stated target of achieving more than 70% recovery at grades above 50% WO₃ and represents a 1.27-fold improvement on the 59.8% recovery reported less than two weeks earlier.
Photo showing separation of scheelite (white) from waste minerals (dark brown) during Wilfley table gravity concentration stage. Wilfley concentrate feeds into the Mozley table cleaning stage. Assayed grade of Mozley table concentrate is 66.6% WO3. Flotation concentrate grading 48.2% WO3 is combined with gravity concentrate to produce final concentrate grade of 56.9% WO3.
Managing director and CEO Julian Woodcock said the company had now met its objective of producing a premium tungsten concentrate while significantly improving recovery rates, supporting a potentially low-capital development pathway for the project.
“We set an objective to obtain >70% recovery >50% WO3 grade, which we have now achieved.
“The metallurgical testwork continues to deliver improvements for the Linka Project, with the combined gravity and cleaner flotation testwork circuit is now delivering 56.9% WO3 concentrate grade at an industry leading 76.0% recovery - a meaningful 1.27x uplift in recovery from the 59.8% reported less than 2 weeks ago.
“We've deliberately kept the flowsheet simple, using proven gravity and flotation technologies, which we believe positions Linka for a low-capital development Project. These results feed directly into the conceptual processing study underway with Mineral Technologies, which will provide our first capital and operating cost estimates.
“With our maiden drilling programme scheduled for the June quarter, we're advancing the metallurgical and resource workstreams in parallel to move the Project forward as efficiently as possible.”
Metallurgical testwork delivers recovery breakthrough
The latest phase of testwork focused on optimising the flotation stage using gravity tailings from a 10-kilogram bulk sample. The combined gravity and flotation circuit produced a 56.9% WO₃ concentrate at 76.0% recovery from feed grading 1.2% WO₃.
The result was achieved through a gravity concentrate grading 66.6% WO₃ at 42.16% recovery combined with a flotation concentrate grading 48.2% WO₃ at 33.89% recovery. Rougher and cleaner flotation recovery more than doubled from 17.1% to 33.89% compared with previous testwork.
The outcome demonstrates a substantial uplift in performance while maintaining a premium concentrate grade above the industry threshold for saleable scheelite concentrates. The company will continue testing different flotation conditions as it seeks to lift recovery beyond 80% while preserving concentrate grades above 50% WO₃.
Gravity and rougher-cleaner flotation flowsheet which achieved a final gravity concentrate of 66.6% WO3 grade and 42.16% recovery. Achieved cleaner 1 concentrate grade of 48.2% WO3 and 33.89% recovery. Combined gravity and cleaner 1 concentrate achieved the final 56.9% WO3 grade at 76.0% recovery.
Low-CAPEX processing pathway takes shape
The metallurgical programme is also helping refine a conceptual processing study being undertaken by Mineral Technologies. Viking said the work supports a "rapid-start" development model centred on physical separation methods rather than more complex chemical processing.
Recent optimisation of the gravity circuit increased standalone gravity concentrate grades to 66.6% WO₃, reinforcing the potential for a simplified modular processing plant. The company believes such a design could reduce capital requirements and shorten permitting and construction timelines compared with conventional tungsten processing operations.
The processing study is expected to provide Viking's first estimates of capital and operating costs for a future development scenario.
Linka positioned amid strong tungsten market
The Linka Project is located in Nevada and forms part of Viking's growing US tungsten portfolio. The company believes the project could benefit from growing efforts to secure domestic and allied-source tungsten supply chains amid elevated market prices.
Viking noted that ammonium paratungstate (APT), the benchmark tungsten pricing product, was trading at about US$3,100 per metric tonne unit in early June 2026. High-grade concentrates such as those targeted at Linka typically attract strong payability from downstream processors.
Next steps include drilling and further optimisation
With key gravity and flotation operating parameters now established, Viking will move into optimisation and variability testing across additional bulk samples collected from the project area. Planned work includes further flotation reagent optimisation, ore sorting studies, comminution testing and ongoing gravity separation trials.
The company is also finalising its conceptual processing study and completing a 3D geological model based on recently digitised historical data.
Importantly, drill permitting has now been approved and Viking's maiden drilling program at Linka is scheduled to commence in the June 2026 quarter, beginning with earthworks and site preparation before drilling starts.
About Viking Mines
Viking Mines is an ASX-listed explorer focused on developing tungsten opportunities in Nevada, United States. Its flagship Linka Tungsten Project is a historical tungsten-producing district where the company is advancing metallurgical studies, resource evaluation and maiden drilling in parallel as it assesses the project's development potential.