Surefire Resources has reported “excellent” final gold recovery results from metallurgical column leach test work carried out at the Yidby project in Western Australia.
The work was completed by Perth-based ALS Global on mineralised core selected from three previously-drilled diamond holes that aimed to understand the gold system and assess if the mineralisation would be amenable to low-cost heap or vat leach gold extraction.
Gold mineralised rock was taken from various depths to obtain structural and metallurgical information.
Previous under-reporting
Surefire confirmed a 68% increase in gold content above previous drill assays due to the prominence of coarse gold (+0.5 millimetres) at the project, indicating there has likely been a significant under-reporting of previous gold grades.
The results were taken from non-agglomerated coarse material (6.33mm) and indicated that a finer crush size could potentially further improve gold recovery and provide a significant upside for the resource grades.
This phase of testing was a continuation from the preliminary sighter level test work carried out in 2022 that showed exceptional gold recoveries of up to 99.5%.
It confirmed the sighter implication that drilling results are significantly under-estimating the quantity of gold hosted within the mineralised lithologies at Yidby.
Managing director Paul Burton said that metallurgical test results always provide more reliable and insightful information than original drill results,” he said.
“For Yidby, these results are very encouraging and provide a solid step-up for the project at a time when gold is increasing in value.”
Large gold system
Yidby is a large gold system located in the Yalgoo-Singleton greenstone belt in WA’s Murchison Province within the Yilgarn Craton, host to multi-million ounce deposits.
Despite its proximity to other gold deposits, the project was not discovered by earlier explorers as it occurs under transported cover.
Yidby contains significant mineralised zones up to 80 metres wide and currently extends over a 3 kilometre strike length, open along strike and at depth.
Drilling intercepts to date contain mineralisation in zones of high grade gold with 5 grams per tonne up to 82g/t as well as broader zones grading 0.2g/t to 1.5g/t.
