Venus Metals and joint venture partner, Rox Resources, have posted an outstanding set of metallurgical results from the Grace gold discovery in Western Australia. First-pass, bench-scale test work on bulk samples from the discovery at Youanmi has returned exceptionally high recoveries of gold through a combination of gravity separation and leaching techniques, with results generating recoveries of up to 99.8 per cent of the contained gold in fresh rock samples.
The Grace gold discovery forms part of the Venus-Rox joint venture over the resurgent Youanmi greenstone belt. The high-grade lode was unearthed in late 2019 and came in the wake of the nearby Penny West Deeps discovery by Spectrum Metals, which demonstrated that the overlooked Youanmi goldfield may still contain a rich endowment of the yellow metal within the bowels of its extensive mineral system.
Grace lies quite literally in the shadow of the old head-frame at Youanmi, sitting a mere stone’s throw from the mothballed Youanmi gold plant and immediately adjacent to the Youanmi main pit, which was previously exploited for a blend of oxide and sulphide ores within the dominant greenstone stratigraphy.
The geology and grade of the mineralisation at Grace sets it apart from other deposits within the Youanmi mine environs. The emerging deposit sits within the granites that bound the Youanmi Shear, with gold mineralisation hosted in a shear zone that exhibits sericitic alteration and is strung with quartz breccias and veining.
Resource drilling continues to return a string of stunning results including intercepts of 25 metres at 34.79 grams per tonne gold, 13m at 60.49 g/t gold and 7m at 54.6 g/t gold. To date, exploration has defined Grace over more than 800m of strike and the JV partners say the high-grade deposit remains open along strike and at depth.
The recent metallurgical test work was completed by ALS Metallurgy in Perth and was designed as a “sighter” program to assess the amenability of the ores to conventional processing and to assist in the design of a broader testing regime as the JV eyes a move into feasibility studies. Two 30-kilogram bulk samples were compiled from the spoil of reverse circulation drilling at Grace, with assaying indicating the samples would be representative of the high-grade ores from the discovery in both the oxide and primary mineralised zones.
The oxide ore sample assayed at an impressive 63 g/t gold, with subsequent preparation including a fine grind and gravity separation which recovered up to 68.91 per cent of the contained gold in the sample. Subsequent leaching of the gravity residue lifted the total gold recovery to 98.73 per cent after only 4 hours of residence time.
The fresh rock sample outperformed its oxide counterpart assaying at a spectacular 93.9 g/t gold. Gravity was shown to recover up to 68.18 per cent of the contained gold, whilst follow up leaching catapulted recoveries as high as 99.83 per cent.
Rox Resources Managing Director, Alex Passmore said: “I am pleased with these excellent initial metallurgical test work results from the Grace deposit. Particularly encouraging is the relatively high gravity recoverable gold from a coarse grind. Gold ores at Youanmi show a variety of metallurgical characteristics however what it is becoming evident that the granite-hosted, low sulphide mineralisation such as that at Grace are free milling (i.e. therefore amenable to conventional CIL).”
Rox, who holds 70 percent of the JV, is also the managing partner of the project that is located 480km north of Perth in the northern Yilgarn Craton of WA.
The JV’s tenure stretches over more than 350 square kilometres of the metalliferous terrane which hosts a number of gold, nickel and zinc prospects and has produced over 667,000 ounces of gold since the precious yellow metal was first discovered in the region more than 100 years ago.
Recent exploration across the under-explored greenstone belt has resulted in a wealth of new discoveries including the delineation of the high-grade Grace gold discovery. Ongoing exploration continues to uncover a string of new prospects including the Junction and Link targets within the environs of the historical Youanmi mine site.
The JV’s development program has focused on the definition of the Grace discovery with both shallow RC drilling and deeper diamond drilling undertaken across the gold-rich prospect. However, with the metallurgical test work confirming the free-milling nature of the ores within the deposit and some outstanding gold recoveries, it is now likely to become a priority target for development and holds the potential to generate an early cash flow for the partners given its ideal position adjacent to the Youanmi mill.
With gold looking to head north of US$1,850 an ounce, uber high grades and long intersections near existing infrastructure that could possibly ride again, Venus and Rox just might be in the right place at the right time.
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