Red Mountain Mining has produced a high-grade 51.8% antimony concentrate from Oaky Creek with excellent 85% recovery, setting the stage for upcoming drilling to define the resource along a 3km mineralised strike in NSW.
- 51.8% antimony concentrate with 85% recovery
- Bulk sample shows low arsenic and deleterious elements
- Five priority drill targets defined for upcoming RC drilling
- Oaky Creek hosts a 3km orogenic antimony system
- Due diligence progressing on US Pioneer Tungsten Project
Exceptional Metallurgy Yields High-Grade Concentrate
Red Mountain Mining (ASX:RMX) has reported outstanding metallurgical test results from a bulk sample taken at its Oaky Creek Antimony prospect in New South Wales. The pilot crush, grind, and flotation study produced a 51.8% antimony (Sb) concentrate, well above the typical commercial grade of 30-40%, with an impressive 85% recovery rate. This concentrate, derived from a ~20kg sample of stibnite vein material, is considered an excellent feedstock for pyrometallurgical processing to produce saleable antimony metal.
The bulk sample, collected from shallow historical pits at Oaky Creek North, returned a head grade of 19.9% Sb and 0.25ppm gold (Au), consistent with previous rock chip assays reaching up to 39.3% Sb. Notably, arsenic (As), a common deleterious element in antimony deposits, was below detection limits (<0.01%), suggesting a cleaner concentrate and potentially lower processing costs. Detailed mineralogical analysis confirmed stibnite as the dominant antimony mineral, comprising 25.2% of the sample, with quartz and carbonate gangue minerals making up the balance.
Flotation Process Confirms Concentrate Quality
Testing at Auralia Metallurgy employed a flotation method with reagents typical for sulfide ores, yielding five concentrates over a total flotation time of 14 minutes. The composite concentrate achieved a 29.7% mass pull, recovering 85% of the antimony relative to the head grade. Gold recovery was significantly lower at 32.8%, indicating it may be locked in solid solution and not readily recoverable by flotation. The low arsenic content in the concentrate (197ppm) further enhances its commercial appeal.
This metallurgical success paves the way for further processing steps, with roasting of the concentrate identified as the logical next stage. The company plans to advance this with larger sample tests, aiming to confirm the quality and consistency of the mineralisation once the upcoming drilling program defines the resource extent.
Drilling Program to Test 3km Mineralised Strike
Oaky Creek is a significant orogenic antimony system stretching approximately 3km, characterised by quartz-carbonate-stibnite veins hosted in folded Carboniferous metasediments. Red Mountain has identified five high-priority drill targets along this strike, which will be tested in a recently approved reverse circulation (RC) drilling program targeting around 2000m of drilling. This follows the completion of an orientation Induced Polarisation survey designed to refine drill collar locations and improve targeting accuracy.
The mineralisation at Oaky Creek shares geological similarities with Larvotto Resources’ Hillgrove Project (ASX:LRV), Australia’s largest known antimony deposit, highlighting the prospectivity of the project area. The company’s extensive soil and rock chip sampling campaigns have delineated coherent antimony anomalies that correlate strongly with mineralised veins, underpinning the rationale for systematic drilling to establish resource continuity and scale. This drilling approval and target definition mark a critical step in advancing the project from exploration to resource delineation, as detailed in the recent NSW approval for up to 32 reverse circulation holes announcement.
Exploration Progress Across US and Australian Projects
Alongside Oaky Creek, Red Mountain continues to progress its US-based critical minerals portfolio. Due diligence activities at the Pioneer Tungsten Project in Montana are advancing on schedule, complementing the company’s broader strategy to develop a diversified portfolio of critical mineral assets across Tier-1 mining jurisdictions. The company is also preparing to restart exploration at its US antimony projects, supported by recent government initiatives and new advisory appointments, aiming to accelerate resource definition and development timelines. This strategic momentum is consistent with the company’s focus on critical minerals essential for global supply chains, as outlined in the exploration restart plans in the US update.
Red Mountain’s Armidale Antimony-Gold Project, where Oaky Creek is located, benefits from its position in the Southern New England Orogen, a recognized Australian antimony province. The project’s geology and mineralisation style align with globally significant orogenic antimony deposits, supporting the company’s confidence in the potential for a substantial resource base pending drilling results.
Bottom Line?
The metallurgical breakthrough at Oaky Creek sharpens focus on the upcoming drilling campaign, which will be pivotal in confirming resource scale and advancing Red Mountain’s critical minerals ambitions.
Questions in the middle?
- Will the upcoming RC drilling confirm grade continuity along the 3km strike at Oaky Creek?
- How will the low arsenic levels impact processing costs and concentrate marketability?
- What are the implications of Pioneer Tungsten due diligence outcomes for Red Mountain’s US strategy?