VKA upgrades tungsten grades with X-ray ore sorting in the USA

Our US tungsten Investment Viking Mines (ASX: VKA | OTC: VKALF) owns the past producing tungsten project in Nevada, USA.

Around 123,000t @ 0.54% tungsten was mined here in the 1940s and 50s, only stopping when the US government ended its tungsten buying program.

VKA recently got drilling underway at the project, the first here in more than 40 years and yesterday reported visible tungsten in its first holes - more on this below.

Today VKA released assay results confirming X-ray ore sorting can deliver a much higher grade feed for its planned processing plant.

The tech works because the X-ray effectively lights up the dense tungsten bearing rocks, letting TOMRA's machinery automatically separate ore from waste.

(source)

The assays on the sorted products came back strong:

1. Conquest pit sample: high grade product of 1.91% WO3 - 3.1x the feed grade.
2. Linka stockpile sample: high grade product of 1.83% WO3 - 4.1x the feed grade.
3. Blends of the sorted products delivered tungsten recoveries of up to 93%.
4. The rejected waste graded just ~0.2% WO3.

(For context, $1.6BN tungsten producer EQ Resources mined grades of just 0.11-0.16% last quarter at Barruecopardo. (source).)

Here is a diagram of the process:

(source)

Rejecting waste before it hits the plant lifts the feed grade, meaning more tungsten can be put through the planned 300,000 tonne per annum plant processing model for the same cost.

It could also upgrade VKA's existing surface stockpiles into viable plant feed, part of the early production opportunity, potentially producing tungsten before needing to mine anything new.

Next up on this part of the workstream is gravity and flotation testwork on the sorted products, plus a TOMRA equipment quote to feed into the plants CAPEX (capital expenditure) model.

We covered the first round of ore sorting results here: VKA - X-ray ore sorting separates tungsten product from waste

What else is VKA up to?

VKA is currently drilling at the project, the first in more than 40 years which got underway within the past couple of weeks.

Just yesterday VKA reported scheelite (which is ~80.5% tungsten) and it glows under UV light, so you can get an indication of the drilling right out of the ground:

(source)

The predominantly red looking garnet on the left actually contains scheelite amongst it under the UV light.

And VKA is seeing these visuals over good widths - the best a 12m continuous interval of visible scheelite from 40m downhole:

(source)

VKA also included a 20m section of drill chips samples under normal lighting and also the UV lamp:

(source)

Visual estimates are no substitute for assays though, the first samples are now headed to the lab, with results expected in 4-6 weeks.

You can see our Deep Dive leading into the drilling here: VKA to start drilling for tungsten in the US any day now...?

What’s next for VKA?

🔄 VKA’s first drill programme at US tungsten project

Here are the milestones we are tracking for the drill programme:

• ✅ Earthworks
• ✅ Drill rig mobilisation to site
• ✅ Drilling starts - visduals hae been reported (source)
• 🔄 Assay results (should start to land in September/October) (source)

🔄 VKA’s rapid restart plan

We also want to see VKA progress its rapid mine restart strategy.

Here are the milestones we are tracking on that front:

• ✅ Assay results from stockpiles + tailings dam
• ✅ Processing study results
• 🔄 Metwork optimisation (Ore sorting + flotation testwork). Continuing to optimise processing choices

🔄 US engagement

This is more of a corporate milestone we want to see VKA hit.

It’s hard to predict when any of these might happen, but we are hoping VKA can attract some sort of US government funding to help finance its project AND/OR attract strategic interest from inside the US.