Brought to you by BULLS N’ BEARS
Rowena Duckworth
Viking Mines has kicked off metallurgical test work at its Nevada-based Linka tungsten project with a result that reads more like a headline than a lab report – a 16-times increase in grade using the simplest processing method in the book.
Initial gravity separation test work on a high-grade Linka Pit sample grading 1.4 per cent tungsten trioxide has delivered a rougher concentrate assaying 22.9 per cent tungsten trioxide with an impressive 63.7 per cent recovery at the coarsest grind size tested.
Linka hosts high-grade scheelite mineralisation within a classic skarn system in Nevada’s Spencer Hot Springs Mining District, about 7 kilometres south of Highway 50.
The skarn has formed at the contact between Ordovician limestone and granitic intrusives – textbook tungsten terrain. Scheelite is one of the most common tungsten minerals, together with its heavier cousin wolframite.
‘A 16-times upgrade through the simplest and cheapest processing method available is a fantastic result.’
Viking Metals managing director and chief executive officer Julian Woodcock
Gravity separation leans on scheelite’s density to mechanically separate it from waste and is the cheapest and simplest beneficiation route available. No exotic chemistry or complex circuits, just simple physics doing the heavy lifting.
Viking Metals managing director and chief executive officer Julian Woodcock said: “Achieving a 16-times upgrade through the simplest and cheapest processing method available is a fantastic result. We are fast-tracking flowsheet development to evaluate low-cost modular solutions and have commenced discussions with processing specialist Mineral Technologies.”
The 63.7 per cent recovery was achieved at the coarsest grind size, 200 microns, suggesting there may be room to further improve recoveries through staged grinding optimisation and cleaner gravity work. Notably, much of the unrecovered tungsten appears as fine scheelite in the tails – material Viking plans to chase up on with new flotation test work.
The deposit’s mineralogy is also cooperating. Microanalytical automated mineralogy QEMSCAN analysis shows the primary waste mineral is garnet with minimal calcite. Calcite can complicate processing flowsheets and increase reagent consumption. Minor calcite, simple mineralogy and strong density contrast are a metallurgist’s trifecta.
Viking is wasting no time and is already in discussions with processing specialists to assess modular, low-cost gravity processing equipment. This kind of plug-and-play solution can dramatically reduce upfront capital and accelerate timelines.
Technical consultants, IMO, and Base Met Labs are overseeing the program to ensure test work meets world-class standards.
Beyond metallurgy, Viking is building momentum on the development front, advancing a 3D geological model, mapping out drill targets for the June quarter and lining up the required federal permitting to get rigs turning.
Linka forms part of Viking’s wider Nevada tungsten grounds, which it acquired late last year. Across four historic sites, the broader Nevada portfolio has previously churned out 123,000 tonnes of ore grading 0.54 per cent tungsten trioxide, underscoring the district’s proven tungsten pedigree.
The Linka project itself is no greenfield mystery. The historic mine produced tungsten during WWII and the Korean War era, with reported production grades between 0.69 and 0.98 per cent tungsten before government buying programs ended.
Tungsten is classified as a critical mineral by the US, UK and Australia due to the metal’s key role in the defence, aerospace, electronics, and manufacturing sectors. In addition, tungsten is characterised by high supply risk due to China’s dominance in production.
However, the biggest use of tungsten is in cemented carbides. Roughly 60 per cent of global tungsten consumption goes into tungsten carbide, which is used in drill bits for mining, oil and gas, as well as metal cutting tools for machining steel and alloys.
Viking’s timing could hardly be better. Global tungsten pricing remains near all-time highs, recently touching US$1,850 per metric tonne unit for ammonium paratungstate – the primary industrial intermediate product for tungsten.
China, as usual, dominates global supply, and with Western governments scrambling to secure all-important critical mineral chains, US-based tungsten projects are suddenly enjoying geopolitical tailwinds barely whispered about a decade ago.
If Viking can continue lifting recoveries while keeping capital intensity in check, Linka could evolve from a simple historic skarn revival into a strategically positioned domestic supply story.
Sixteen times uplift on the first shake of the table suggests there may be more weight to come. This may well be the story that lights up the tungsten space.
Is your ASX-listed company doing something interesting? Contact: mattbirney@bullsnbears.com.au
