Red Mountain Mining (ASX: RMX) has commenced metallurgical test work on a 20-kilogram bulk sample of quartz-stibnite vein and breccia material from multiple historical pits at the Oaky Creek antimony prospect within its Armidale antimony-gold project in New South Wales.
The sample will be subjected to detailed mineralogical characterisation and a comprehensive crush, grind, and flotation study to define processing behavior and concentrate potential of the ore, which is considered to be a key step towards commercially validating the asset.
Auralia Metallurgy is completing the work in parallel with ongoing exploration—part of an accelerated strategy to demonstrate processing viability and materially de-risk the Oaky Creek mineralisation ahead of planned drilling.
Processing Performance
The workflow is designed to provide a rapid indication of processing performance of the Oaky Creek mineralisation and will employ XRD-EDS and QEMSCAN analytical techniques to identify and quantify antimony sulfide and oxide phases.
Based on Red Mountain’s field observations, these are expected to include stibnite, stibiconite, senarmontite and valentinite and may include contaminants such as arsenopyrite and other arsenic and lead-bearing minerals.
Mineralised stibnite-bearing vein and breccia samples previously collected at Oaky Creek have consistently contained coarse-grained stibnite crystals.
This suggests that the material will have favourable liberation characteristics, potentially reducing the degree of grinding (and therefore energy use) required during processing.
Work will also assess and optimise antimony recovery into a marketable concentrate containing up to 40% antimony, with cost-effective scoping crucible smelting tests on sub-samples of up to 3kg is expected to validate downstream processing viability.
Oaky Creek Mineralisation
The Oaky Creek prospect features quartz-carbonate-stibnite veins and breccias hosted within a tightly-folded and faulted sequence of metamorphosed carboniferous mudstone, siltstone, and fine sandstone.
The mineralisation has been targeted by two groups of shallow historical pits and shafts at Oaky Creek North and Oaky Creek South.
Red Mountain’s initial sampling at Oaky Creek centered on a major area of the Namoi Fault.
That work defined a coherent, 1.5-kilometre long antimony-in-soil anomaly extending north and south of historical workings at Oaky Creek North.
It also identified a 1km-long antimony-in-soil anomaly of similar orientation extending north from the Oaky Creek South workings.
