Resolution Minerals Ltd (RML.AX) Antimony Trioxide Produced from Antimony Ridge

ANTIMONY RIDGE METALLURGY ADVANCING WITH ANTIMONY TRIOXIDE PRODUCED

Adelaide, April 14, 2026 AEST (ABN Newswire) - Resolution Minerals Ltd (ASX:RML) (NC3:FRA) (RLMLF:OTCMKTS) reported that an intermediate antimony trioxide product has been produced from large samples of stibnite from the Antimony Ridge open pits, by the respected lab, Kingston Process Metallurgy (KPM), in Ontario.

HIGHLIGHTS

Antimony Trioxide Produced: Antimony trioxide product has been produced from large samples of stibnite from the Antimony Ridge historical open pits, using the conventional pyrometallurgical process of volatilisation, producing an intermediate product, with 99.38 wt% Antimony Trioxide (Sb2O3wt%) content.

Further Antimony Trioxide Refining Test Work: Further refining pyrometallurgical test work is underway and final product results will be released in the coming weeks.

Conventional Pyrometallurgy: Pyrometallurgy would be the base-case, conventional technology for processing antimony, with initial tests conducted by KPM in Ontario to produce antimony trioxide. A number of third parties have been approached regarding this processing option.

Mineral Processing Test Work Progressing: Test work is advancing on Antimony-bearing stibnite veins, that have returned exceptionally high-grade Antimony (Sb) consistently above 30% up to 50% Sb in recent results, mined historically during World War I &II and the Korean War, from Antimony Ridge, within Resolution's Horse Heaven Antimony-Tungsten-Gold-Silver Project ("Horse Heaven") (ASX announcement 15 September 2025).

Concentrate Test Work: Test work is advancing on options to concentrate the antimony ore, tungsten and gold at IMO labs in Perth, Australia.

Hydrometallurgy Progressing: Test work on Antimony Ridge samples using hydrometallurgical processing is underway at ANSTO in Australia and results will be released once available.

Current Lack of US Processing Options: Resolution's goal is to develop a hydrometallurgy processing hub for antimony, as stibnite, in Idaho USA, due to the lack of modern processing options in the USA for antimony.

Numerous Vein Swarms: 3D modelling of numerous known antimony and silver bearing veins, veins swarms and stockworks, over a large area (1,000m x 700m) (170 acres), has revealed significant size and expanding scale potential at Antimony Ridge (ASX announcement 10 April 2026).

FAST-41: Horse Heaven wasselected for the U.S. FAST-41 Transparency Coverage by the US-based Permitting Council, expected to accelerate permitting timelines with an application for 250 drill holes and large-scale bulk sampling (ASX announcement 8 April 2026).

Antimony Ridge forms part of Resolution's broader Horse Heaven strategy, which includes recently acquired processing infrastructure, tungsten stockpiles and a major 2026 drilling program at Golden Gate starting in May.

Metallurgy test work is advancing on antimony-bearing stibnite veins, that have returned exceptionally high-grade antimony (Sb) consistently above 30% up to 50% Sb in recent results.

Conventional pyrometallurgy test work would provide the base-case data for processing antimony, with initial tests conducted by KPM in Ontario to produce antimony trioxide as an intermediate product. Final product results will be released in coming weeks. A number of third parties have been approached regarding this processing option.

Test work on Antimony Ridge samples using hydrometallurgical processing is underway at ANSTO in Australia and results will be released once available.

Test work is advancing on options to concentrate the antimony ore, tungsten ore and gold-bearing samples at IMO labs in Perth, Australia.

Resolution's plan is to develop a hydrometallurgy processing hub for antimony, as stibnite, in Idaho USA, due to the lack of modern processing options in the USA for antimony.

Adam Roper, PhD, Resolution's In-house Senior Metallurgist, stated: "The initial pyrometallurgical results from processing Antimony Ridge samples are very encouraging with few impurities. This is a great start and I'm looking forward to discussing the final results in the coming weeks.

"Resolution's goal is to develop a processing hub in Idaho for stibnite and I'm relishing the opportunity to bring this to fruition, from mine to product.

"The Johnson Creek Mill site, at the base of Antimony Ridge, is being considered as a fast track option for potential development of a local processing site, given it has the necessary infrastructure on site, with power and water, and is on 10 acres of private land owned 100% by RML."

Ari Zaetz, RML's Managing Director, stated: "With the recent US Government Permitting Council provided via FAST-41 Coverage to accelerate permits, Resolution is in parallel developing further local processing plans to enable antimony and tungsten supply for US demand. Our unique combination of critical minerals assets makes us well placed to deliver."

Results of recent 3D modelling of the numerous antimony and silver-bearing veins and vein swarms that are exposed over a large area (1,000m x 700m) in past mining pits, reveals the potential for a significant size antimony-silver deposit at Antimony Ridge, with an open-ended target and expanding scale potential.

This result follows the selection of Antimony Ridge for FAST-41 Transparency Coverage from the US Permitting Council, announced on 8 April 2026. Selection reflects the strategic importance of Antimony Ridge as a potential source of U.S. domestic antimony supply, a critical metal essential for defence, energy, and industrial applications.

Historical mining occurred at Antimony Ridge by the US Government during World War I, WWII and the Korean War. During World War II, the local District, including the adjoining Stibnite mine (Perpetua Resources), is estimated to have produced more than 90% of the US Antimony (Source: Perpetua Resources Stibnite Feasibility Study, Jan 2021). Antimony Ridge was a key source of Antimony for the US military. Antimony Ridge is located within Resolution's Horse Heaven Antimony-Tungsten-Gold-Silver Project in Idaho, USA, and immediately adjacent to Perpetua Resources' Stibnite Gold Project, a large, recently permitted Antimony-Gold project.

Future Plans

Resolution plans to commence a significant bulk sampling program of high-grade antimony ore and conduct an extensive drilling program up to 250 drill holes, once a Plan of Operations is approved (ASX announcement 8 April 2026). Antimony trioxide product has been produced from large samples of stibnite from the Antimony Ridge historical open pits. Further refining pyrometallurgical test work is underway and final product results will be released in the coming weeks. Antimony Ridge is expected to be a cornerstone of Resolution'sstrategy to supply critical metals, including Antimony, Tungsten and Gold, from central Idaho in the USA.

Resolution is initiating a major Phase 2 drilling program in May 2026, at the Golden Gate Project, of up to 45,000 ft (13,700 metres) of diamond core drilling located within the Company's larger Horse Heaven Antimony-Tungsten-Gold-Silver Project. The program is designed to define the scale of gold and tungsten mineralisation at Golden Gate and Golden Gate South and support progression toward a maiden Mineral Resource Estimate.

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About Resolution Minerals Ltd

Resolution Minerals Ltd (ASX:RML) (OTCMKTS:RLMLF) (FRA:NC3) is a mineral exploration company engaged in the acquisition, exploration and development of precious and battery metals - such as antimony, gold, copper, and uranium. 

Resolution Minerals Ltd Listed on the ASX in 2017 and has a broad portfolio of assets, such as the Drake East Antimony-Gold Project in north-eastern NSW and George Project prospective for silica sand and uranium.

    

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