Viking Mines (ASX:VKA) reports upgraded tungsten products from Linka ore sorting testwork
Viking Mines has reported assay results from X ray Transmission (XRT) ore sorting testwork completed by TOMRA on mineralised material from the Linka Tungsten Project in Nevada, USA.
The sorted fractions were assayed at Base Met Labs, with the metallurgical balance confirming that the ore sorting process separated the mineralised feed into higher grade product streams and a low grade stream in both samples.
Highlights
Conquest Pit sample combinations of sorted products delivered 1.2x to 1.7x the feed grade, with tungsten recoveries of up to 93.0%.
Linka Stockpile sample combinations of sorted products delivered 1.3x to 1.4x the feed grade, with tungsten recoveries of up to 85.9%.
The Conquest Pit high grade product returned 1.91% WO3, approximately 3.1x the calculated feed grade of 0.61% WO3, containing 27.3% of the tungsten in 8.8% of the mass.
The Linka Stockpile high grade product returned 1.83% WO3, approximately 4.1x the calculated feed grade of 0.45% WO3.
The Conquest Pit sample was processed through a three stage cascade sorting configuration on TOMRA’s XRT platform, producing four output streams: High Grade Inclusions, Low Grade Inclusions, CONTAIN™ Inclusions and low grade material.
The high grade product graded 1.91% WO3, approximately 3.1x the calculated feed grade of 0.61% WO3, and contained 27.3% of the tungsten in 8.8% of the mass.
The low grade stream graded 0.18% WO3, containing 7.0% of the tungsten in 23.5% of the mass.
Combining the sorted products with unsorted fines provided a range of feed options for the Conquest Pit sample, delivering 1.2x to 1.7x the feed grade at tungsten recoveries of 62.1% to 93.0%.
The minus 10 mm product was also identified as suitable for recombination with selected eject streams to produce feed for processing.
The Linka Stockpile sample returned a high grade product grading 1.83% WO3, approximately 4.1x the calculated feed grade of 0.45% WO3, while the low grade stream graded 0.20% WO3, containing 14.1% of the tungsten in 31.1% of the mass.
Combining the sorted products with unsorted fines delivered 1.3x to 1.4x the feed grade, with tungsten recoveries ranging from 40.3% to 85.9%.
Viking Mines Managing Director and CEO Julian Woodcock said the results provided flexibility in selecting combinations of sorted products.
“By selecting different combinations of the sorted products, we can prioritise either grade uplift or tungsten recovery. This data will now inform how ore sorting may be incorporated into the conceptual process flowsheet for the Linka Project.”
The company stated that the results support two applications for ore sorting at the Linka Tungsten Project, including pre concentration of run of mine feed by rejecting waste or low grade material ahead of the processing plant, and upgrading existing surface stockpiles.
The results will be integrated into the conceptual processing flowsheet being developed by Mineral Technologies for the ~300,000 tonne per annum processing model.
The next steps include completing gravity and flotation testwork on the ore sorting products at Base Met Labs to assess downstream processing performance, assessing the application of ore sorting to upgrade existing surface stockpiles, reviewing the conceptual flowsheet to incorporate an ore sorting stage, and obtaining a TOMRA equipment quotation to support the 300ktpa CAPEX model being developed by Mineral Technologies.