Viking Mines (ASX:VKA) reports assay results confirming ore sorting technology has successfully produced ‘high-grade’ tungsten products at its Linka Tungsten Project in Nevada, US.
Earlier this month, Viking announced visual scheelite intercepts from its maiden drilling at Linka, as reported by Mining.com.au. The company has now confirmed that ore sorting test work can produce ‘high-grade’ tungsten products, with grade increases of up to 4.1 times the feed grade.
TOMRA X-ray transmission (XRT) test work delivered grade upgrades of 1.2–4.1 times feed grade across two samples, with tungsten recoveries reaching 93%.
Managing Director Julian Woodcock says the results demonstrate the technology’s flexibility in prioritising either grade uplift or tungsten recovery.
“These assay results confirm what we observed visually in June. Ore sorting has produced a high-grade product at up to [4.1] times the feed grade in both samples, while rejecting a low-grade stream grading just 0.2% WO3 [tungsten trioxide],” Woodcock adds.
The Conquest Pit sample produced a ‘high-grade’ product grading 1.91% WO3, approximately 3.1 times the calculated feed grade of 0.61% WO3, containing 27.3% of the tungsten in just 8.8% of the mass.
The Linka Stockpile sample delivered an ‘even higher upgrade ratio’, with the ‘high-grade’ product grading 1.83% WO3 at approximately 4.1 times the feed grade of 0.45% WO3.
Both samples produced ‘low-grade’ reject streams grading approximately 0.2% WO3, demonstrating the technology’s potential to screen waste from ‘low-grade’ stockpiles and upgrade material to ore-grade feed.
Combining sorted products with unsorted fines provides multiple feed options. The Conquest Pit sample delivers 1.2–1.7 times the feed grade at tungsten recoveries of 62.1% to 93%. The Linka Stockpile sample achieves 1.3–1.4 times the feed grade with recoveries up to 85.9%.
Viking processed each sample through a three-stage cascade sorting configuration using TOMRA’s XRT platform, producing four output streams: ‘High-Grade’ Inclusions, ‘Low-Grade’ Inclusions, CONTAIN Inclusions, and ‘low-grade’ material.
The company says ore sorting could provide two distinct value sources: pre-concentration of run-of-mine feed to lift plant feed grade and upgrading existing surface stockpiles to convert ‘lower-grade’ material into viable plant feed.
Viking is completing gravity and flotation test work on the sorted products at Base Met Labs to assess downstream processing effectiveness.
The results will be integrated into the conceptual processing flowsheet being developed by Mineral Technologies for the 300,000 tonnes per annum processing model.
Viking Mines is an Australian explorer advancing gold and battery metals projects in Western Australia alongside its US tungsten assets.
Write to JC Villarba at Mining.com.au
Images: Viking Mines
