Argosy Minerals Achieves Target Lithium Concentration in Rincon Brine Pilot Tests, Advancing 12,000 TPA Project

Overview of Argosy’s Rincon Lithium Project and Strategic Development

Listed on the ASX, Argosy Minerals Limited is developing the Rincon Lithium Project in Argentina’s Salta Province. The company is advancing engineering and feasibility studies to complete the DFS for a 12,000 tonne per annum lithium production target. Rincon is a significant resource asset central to Argosy’s strategic objectives in the lithium brine sector, which benefits from strong global demand for lithium in batteries and energy storage.

Argosy’s development approach emphasizes validating process technologies and operational parameters through extensive laboratory and pilot-scale testing. Each major unit operation in the planned process flowsheet undergoes rigorous validation before progressing to final feasibility and detailed design. This structured engineering methodology aims to reduce technical and commercial risks, ensuring confidence in the project’s profitability at scale.

Successful Mechanical Evaporation Testworks Reach Concentration Goals

Using proprietary technology from an independent European provider, Argosy conducted pilot-scale evaporation and concentration testing on lithium brine previously concentrated via solvent extraction (SX). The pilot program proved mechanical evaporation can efficiently concentrate post-SX Rincon brine from about 1.3 weight percent lithium to the target 4–5 weight percent range, reducing solution volumes and potentially improving downstream lithium recovery.

The tests confirmed the brine can be concentrated 4 to 6 times under continuous operation, demonstrating stable performance for potential commercial use. This concentration capability is critical for process design and economics, impacting throughput and extraction efficiency. The results validate mechanical evaporation as a feasible process route for Rincon.

Technical Performance and Operational Stability

The evaporation testworks revealed no significant technical challenges such as foaming, scaling, or salt precipitation within the target operating range. These issues commonly hinder lithium brine processing by reducing equipment efficiency and increasing mitigation costs. Their absence suggests the mechanical evaporation process offers operational robustness compared to alternative methods.

Water removal efficiency was also confirmed, with 75–83% of feed volume recoverable as condensate water while maintaining lithium concentration in a smaller volume. This enhances process sustainability by reducing lithium-depleted brine disposal and potentially generating valuable by-products. The engineering and operational data generated support DFS design, equipment sizing, and economic modeling, enabling greater confidence in project cost and scheduling.

Reducing Process Risk and Enhancing the Definitive Feasibility Study

Argosy’s management highlighted that the positive testworks demonstrate mechanical evaporation as a viable concentration method, strengthening the DFS by lowering process risk and improving understanding of brine behavior. Managing Director Jerko Zuvela stated the company is "pleased to continue achieving successful testwork results that support our overall engineering and feasibility works program to complete the DFS," calling these outcomes "a significant milestone towards developing our 12ktpa Rincon Lithium Project."

The testworks align with Argosy’s goal to minimize technology risk and complete the DFS to a level that assures stakeholders the Rincon project can be built and operated profitably. Systematic validation of each process step through laboratory and pilot testing builds a technically sound and economically viable foundation. The DFS is a critical milestone for transforming Rincon into a development-ready project capable of attracting capital and strategic partners.

Integration of Solvent Extraction and Downstream Processing

The mechanical evaporation tests used lithium brine concentrated by Argosy’s earlier solvent extraction (SX) program. SX selectively removes lithium from raw brine, leaving impurities behind. Combining SX with mechanical evaporation enables progressive lithium concentration through optimized sequential unit operations, maximizing lithium recovery while minimizing impurities.

This integrated process flowsheet has been proven technically feasible at pilot scale. Concentrating post-SX brine to 4–5 weight percent lithium improves downstream crystallization or precipitation economics, as these stages perform better at higher lithium concentrations. Argosy’s technology selection aims to maximize lithium yield, reduce water use, and lower operating costs at the 12,000 tonne per annum scale.

Lithium Market Dynamics and Supply Security

The Rincon project operates within a global lithium market driven by sustained demand from battery makers, electric vehicle manufacturers, and energy storage developers. South America’s lithium triangle, including Argentina’s Salta Province, hosts significant brine deposits with established infrastructure and regulatory support. Rincon’s location offers strategic access to lithium markets in the Americas and contributes to supply chain diversification for international customers.

Investors and industry stakeholders closely watch lithium supply security and new capacity developments. Argosy’s progress toward production readiness at Rincon enhances global lithium supply and offers a potential long-term source for strategic partners. The company’s thorough technology validation and process optimization aim to establish Rincon as a reliable, competitive lithium supplier meeting international quality and cost standards.

Resource Base and Updated Technical Assumptions

Argosy announced the Rincon Lithium Project JORC Mineral Resource Estimate in January 2024 and updated it on 12 November 2024. The 12,000 tonne per annum production target is based on applying modifying factors to Measured, Indicated, and Inferred Resources. The company confirms all material assumptions from the 12 April 2024 update titled "Updated – Dynamic Modelling Produces Outstanding Results" remain valid, ensuring consistency across resource estimates, production targets, and ongoing engineering programs.

The testwork program validates technical assumptions underpinning production targets and refines cost and schedule estimates as engineering progresses. Each successful test reduces technical uncertainty and builds confidence in achieving the 12,000 tonne per annum goal. Jerko Zuvela, a Member of the Australasian Institute of Mining and Metallurgy (AusIMM), oversees the testwork, providing independent verification of technical quality and validity.

Next Steps in Engineering and Project Milestones

Argosy continues comprehensive engineering and feasibility work to complete the Rincon DFS. The successful evaporation and concentration tests are one part of the broader DFS validation. Additional major unit operations require laboratory and pilot testing before the DFS reaches an investment-ready standard. The engineering roadmap includes solvent extraction, mechanical evaporation, crystallization or precipitation, and separation unit designs, each needing process validation, equipment specification, and cost estimation.

Upcoming milestones include completing remaining testwork, advancing plant design, preparing capital and operating cost estimates, and evaluating environmental and social impacts. The DFS timeline and development sequence will influence progress toward detailed engineering, equipment procurement, and financing. Investors should monitor DFS publications and announcements regarding capital needs, timelines, partnerships, or financing as the engineering program advances.

Commercial and Strategic Impact of Testwork Success

The successful evaporation and concentration testworks mitigate a key technical risk by confirming lithium brine can be concentrated to specifications under continuous operation. This supports Argosy’s ability to demonstrate project feasibility to investors, financiers, and strategic partners interested in lithium supply or project involvement. The critical engineering data enable more accurate cost and schedule estimates, enhancing commercial credibility.

Reducing technology risk through systematic validation strengthens Argosy’s negotiating position with partners, suppliers, and financiers. Pilot-scale data significantly lowers perceived execution and operational risks compared to projects relying solely on modeling. Argosy’s rigorous engineering approach positions Rincon as a mature development opportunity attractive for capital investment and partnerships with experienced lithium producers or consumers. Management views the testwork results and DFS completion as essential steps toward realizing the 12,000 tonne per annum Rincon Lithium Project.