Resolution Minerals Ltd (ASX:RML, OTCQB:RLMLF, FRA:NC3) has produced high-grade tungsten concentrates of more than 52% tungsten trioxide (WO₃) from historical stockpiles at its Horse Heaven project in Idaho, delivering a strong upgrade from previously low-grade material.
Preliminary metallurgical test work delivered a 19-fold upgrade from the original stockpile grade of around 1.85% WO₃, using simple gravity separation techniques.
The results come from material sourced from the historic Golden Gate tungsten mine and processed at the nearby Johnson Creek mill site, reinforcing the company’s strategy to extract value from existing stockpiles while advancing broader exploration.
Strong upgrade from simple processing
The company said heavy liquid separation (HLS) test work achieved concentrate grades of up to 52.3% WO₃ with recovery rates reaching 75.5%, highlighting the amenability of the material to relatively straightforward processing methods.
Notably, finer particle sizes delivered improved outcomes. As shown in the test data, both grade and recovery increased as material was crushed more finely, pointing to a clear optimisation pathway for future processing.
Tungsten Stockpiles HLS results show decreasing particle size increases both grade and recovery of tungsten bearing ore originally from the historical mine at Golden Gate Tungsten.
The work builds on earlier sampling that confirmed the stockpiles contain tungsten predominantly as scheelite, alongside minor gold content and low levels of impurities — a favourable combination for downstream processing.
Advancing towards potential production pathway
While the test work remains at an early stage, the results support the potential for low-cost, near-term processing of stockpiled material — an attractive proposition as global demand for critical minerals such as tungsten continues to rise.
Resolution’s in-house metallurgist Dr Adam Roper described the initial findings as “encouraging for the short-term processing of the historical tungsten stockpiles via simple gravity methods,” with further results expected in coming weeks as larger samples are processed.
The company is now progressing additional test work on a larger 50-kilogram sample using shaker table concentration, aimed at refining the final product specifications.
At the same time, discussions with tungsten smelters and refiners are under way, signalling early moves towards establishing a commercial pathway for any future concentrate production.
Broader Horse Heaven strategy taking shape
The tungsten processing work forms part of Resolution’s broader development strategy at Horse Heaven, which hosts antimony, tungsten and gold mineralisation across a large landholding in Idaho.
The project sits in a historically significant district that once supplied a substantial share of US tungsten and antimony, and it is located adjacent to Perpetua Resources’ Stibnite project — a major permitted antimony-gold development.
Antimony Ridge – As part of Resolution’s larger Horse Heaven Antimony-Tungsten-Gold-Silver Project – Relationship of Antimony Ridge (Sb) with Golden Gate (Au) and Golden Gate Tungsten (W).
Resolution has been steadily building momentum at Horse Heaven in recent months, including advancing antimony processing studies and raising $20 million to support exploration and potential US listing ambitions.
Looking ahead, the company is preparing a major Phase 2 drilling program of up to 13,700 metres at Golden Gate and Golden Gate South, targeting both gold and tungsten mineralisation and aiming to support a maiden resource estimate.
Unlocking value from stockpiles
The latest results also underscore a broader theme in Resolution’s strategy — unlocking value not just from in-ground resources, but from historical material already mined and stockpiled.
With further metallurgical work, detailed sampling and potential processing pathways under evaluation, the stockpiles could provide an earlier-stage revenue opportunity while the company continues to define the scale of the wider system.
The combination of high-grade concentrate results, improving processing flowsheets and ongoing drilling plans positions Horse Heaven as a multi-commodity project with both near-term and longer-term development potential.