Resolution Minerals (ASX: RML) has reported the near-complete recovery of stibnite (antimony sulphides) from a 15 kilogram lower-grade sample of mineralisation taken from the historical Antimony Ridge project in Idaho.
Initial rougher flotation testing by IMO Labs in Western Australia returned a 99.5% sulphur recovery from samples containing less than 10% antimony.
It is seen as an encouraging indication for Resolution’s future operations, even if high-grade antimony were to be diluted by surrounding waste or gangue material during extraction.
IMO is still to conduct further testing including “cleaner” stages focused on achieving grades of more than 50% antimony from the rougher sulphide concentrate.
Encouraging Recovery Rates
The high rates of antimony recovery in concentrates support previously reported 99.38% antimony trioxide produced from large Antimony Ridge open-pit samples using the conventional pyrometallurgical process of volatilisation.
Previous 3D modelling of the project revealed significant size and expanding scale potential by showing a 0.68 square kilometre area with numerous known antimony and silver-bearing veins, veins swarms and stockworks.
The company views the positive preliminary concentration results for stibnite recovery and amenability of the previous high-grade samples to volatilisation reflective of “very encouraging” progress for the future development of Antimony Ridge.
Critical Minerals Cornerstone
Resolution expects Antimony Ridge be a cornerstone of its strategy to supply critical metals including antimony, tungsten, and gold from a hub in central Idaho.
The project forms part of the company’s broader Horse Heaven project, which includes recently acquired processing infrastructure, and historical tungsten stockpiles.
A 13,700m diamond drilling program is scheduled to commence at the Golden Gate target this week.
Drilling will look to define the scale and extent of gold mineralisation at Golden Gate North and Golden Gate South along strike and at depth and support a maiden mineral resource estimate in the first quarter of 2027.
