How Locksley’s 68% Antimony Concentrate Could Reshape US Supply Chains
Locksley Resources has produced a high-grade antimony concentrate exceeding market standards from its Desert Antimony Mine in California, marking a significant step toward a fully domestic US antimony supply chain.
- 68.1% antimony concentrate grade achieved, surpassing 55% market requirement
- Concentrate purity approaches theoretical maximum stibnite grade of 71.68%
- Antimony recovery rates expected to exceed 80% after further flotation optimization
- Bulk sampling and pilot production planned to advance metallurgical development
- Supports US strategic goals for critical mineral independence and supply chain resilience
High-Grade Concentrate Breakthrough
Locksley Resources Limited (ASX – LKY) has announced promising metallurgical test results from its Desert Antimony Mine (DAM) Prospect, part of the Mojave Project in California. The company achieved a high-grade antimony concentrate of up to 68.1% through a second stage cleaner flotation process. This grade significantly exceeds the minimum marketable threshold of 55% and nears the theoretical maximum purity of stibnite, the primary antimony mineral, at 71.68%.
Implications for US Critical Mineral Supply
Antimony is a critical mineral with essential applications in defense, semiconductors, and energy systems. The United States currently lacks domestic production, relying heavily on imports, primarily from China. Locksley’s success in producing a high-purity concentrate from preliminary tests positions the Mojave Project as a potential cornerstone for a 100% Made in America antimony supply chain. This aligns closely with US government priorities to secure and diversify critical mineral sources for national security and industrial resilience.
Recovery and Process Optimization
Initial flotation testwork demonstrated antimony recoveries of 81.9% in the rougher stage and 60.5% in the cleaner stage. The company expects to improve overall recovery rates beyond 80% through further optimization, including recycling flotation tails and extending residence times in cleaning stages. These promising recovery metrics suggest that minimal additional flowsheet development is required to maximize both grade and recovery, potentially accelerating project timelines.
Next Steps and Development Plans
Locksley is advancing its metallurgical program with plans to collect bulk samples from underground workings to expand testwork. This will include flotation optimization, gravity separation, ore sorting, and pilot-scale production of antimony metal ingots and compounds. The company is also collaborating with Rice University to explore innovative extraction techniques using Deep Eutectic Solvent technology. Concurrently, drilling permits are pending, and further exploration at the Mojave Project and other assets like the Los Lirios deposit in Mexico is planned.
Strategic Positioning in a Competitive Landscape
Located adjacent to MP Materials’ Mountain Pass Mine, the Mojave Project benefits from strong geological continuity and proximity to established rare earth element operations. Locksley’s focus on critical minerals, including antimony and rare earths, places it at the forefront of efforts to reduce US dependence on foreign supply chains. The company’s Australian Tottenham Project adds diversification but the Mojave Project remains the flagship for critical mineral development.
Bottom Line?
Locksley’s high-grade antimony breakthrough sets the stage for advancing a vital US critical mineral supply chain amid growing geopolitical urgency.
Questions in the middle?
- How will Locksley’s upcoming bulk sampling and pilot production impact project timelines and capital requirements?
- What are the potential challenges in scaling flotation recovery rates beyond 80% in commercial operations?
- How might US government policies and funding influence Locksley’s ability to fast-track the Mojave Project?
