Argosy Minerals Progresses Rincon Lithium Project with Successful Feasibility and Engineering Milestones for 12,000tpa Output

Rincon Project Overview and Stage 1a Development Strategy

Argosy Minerals is developing the Rincon Lithium Project as a 12,000 tonnes per annum operation in Salta Province, Argentina. The company has engaged global technology and engineering service providers along with lithium process consultants to execute the required engineering and feasibility studies. The Stage 1a feasibility phase focuses on producing solid lithium chloride onsite, offering advantages such as reduced upfront capital intensity, simplified processing, and lower operational risk.

The process flowsheet, combined with a phased project development strategy, establishes a scalable pathway from raw lithium brine to solid lithium chloride product, ultimately progressing to battery-grade lithium carbonate or hydroxide. This staged approach provides development flexibility and mitigates project risk, enabling Argosy to manage the capital-intensive nature of lithium processing while preserving future expansion options. Managing Director Jerko Zuvela emphasized strong progress in feasibility and engineering works and expressed confidence in meeting forthcoming milestones for a successful Definitive Feasibility Study.

Solvent Extraction Testwork Achieves 99% Lithium Chloride Purity

Continuous pilot-scale solvent extraction testworks conducted in Salta validated lithium purity, yield, and operational stability. Using concentrated lithium brine, the company successfully produced high-purity lithium chloride concentrate with the designated process technology. Results demonstrated 99% lithium chloride purity and a maximum lithium yield of 94.4%, exceeding testwork targets. These outcomes significantly validate process capability and provide critical parameters for the Definitive Feasibility Study.

The testing confirmed stable lithium chloride production with promising productivity and quality metrics. The solvent extraction process demonstrated technical feasibility and scalability potential. Longer operation times improved system recovery, purity, and stability, reinforcing confidence in the process design. Following these results, Argosy is advancing engineering efforts with the technology provider to develop a process design package for integration into the Definitive Feasibility Study.

Brine Pre-Concentration and Evaporation Pond System Engineering

As part of the Definitive Feasibility Study, multiple work phases address lithium brine pre-concentration. Evaporation pond system design includes pond sizing, layout, depth, earthworks, liners, and brine transfer systems, currently underway. Concurrently, design progresses on the borefield-to-pond brine gathering system, encompassing pipelines, pumping stations, valves, manifolds, and instrumentation. Additionally, evaporation pond end-product concentrated brine holding ponds and pond-to-process plant delivery systems are being developed.

A pond operations management plan has been created, covering seasonal operation philosophy, inter-pond transfers, and harvesting strategies. These comprehensive designs establish the front-end infrastructure essential for feeding lithium brine into the processing flowsheet. European pilot testworks on forced evaporation technology confirmed suitability for Rincon brine, consistently achieving required concentration factors with high energy efficiency, low maintenance, and minimal scaling or fouling.

Crystallisation Testwork and Feasibility Engineering Package Advancements

Ongoing crystallisation testworks in Europe use lithium chloride solution from solvent extraction pilot campaigns in a two-stage program. This testing evaluates progressive concentration increases and impurity solubility limits to optimize crystallisation flowsheet and product quality. Completion is anticipated in the coming weeks, marking a near-term project milestone. Based on current results, feasibility basic engineering package works have commenced in Europe, with completion targeted by end-September.

The crystallisation stage is vital as the final step in producing solid lithium chloride onsite. The methodical testing of concentration factors and impurity limits underscores Argosy's dedication to optimizing product quality and establishing reliable operating parameters. The Definitive Feasibility Study engineering package for evaporation operations is under review, with final evaporation technology decisions pending flowsheet modelling outcomes, ensuring design flexibility.

Essential Engineering Data Supporting Definitive Feasibility Study

Testwork programs are critical to delivering a Definitive Feasibility Study that assures stakeholders of the Rincon Lithium Project’s profitable construction and operation. Each key unit operation in the process flowsheet has undergone laboratory and pilot-scale validation, with testing nearing completion. Results have been highly encouraging, revealing no unresolved issues or flaws across test programs.

These results strongly validate the process flowsheet’s capability and enhance confidence in the process design’s robustness. The data will define key operational and economic parameters incorporated into the Definitive Feasibility Study, guiding equipment sizing and economic evaluations. Argosy confirms that all material assumptions supporting the production target remain unchanged since previous announcements on 12 April 2024, 12 November 2024, and 13 January 2025.

Strategic Location Benefits and Infrastructure Access

Argosy’s Rincon Lithium Project enjoys significant location advantages with access to grid power, industrial water, and transport infrastructure. These factors substantially reduce capital expenditure compared to many lithium projects requiring new infrastructure development. Proximity to established industrial water supplies and transport routes lowers upfront capital intensity, a key benefit of the Stage 1a development strategy. Grid power access is especially valuable for energy-intensive lithium processing operations.

Located in Salta Province, Argentina, the project benefits from an established mining region with proven infrastructure and regulatory frameworks. This positioning reduces development risk and timelines by leveraging existing utilities and transport networks. Management highlights this infrastructure advantage as critical to the project’s economics and competitiveness within the global lithium market, especially amid capital-intensive production and prevailing cost pressures.

Process Technology Validation and Operational Stability

Multiple testwork programs across unit operations have validated Argosy’s core technology approach and bolstered confidence in operational stability. Solvent extraction tests showed that extended operation enhances recovery, purity, and stability, indicating a scalable, stable process. Evaporation tests confirmed the technology’s suitability for Rincon brine, achieving concentration factors efficiently with low maintenance. Collectively, these results demonstrate the integrated flowsheet’s viability.

The absence of key issues throughout comprehensive testwork marks a major de-risking milestone. Pilot-scale validation of each critical unit operation supports engineering confidence for commercial-scale functionality. Demonstrated technical feasibility via independent testwork by specialized providers strengthens the Definitive Feasibility Study foundation. The staged development approach, starting with solid lithium chloride production in Stage 1a, offers a realistic and economically viable initial phase with potential for future upgrades to battery-quality products.

Definitive Feasibility Study Schedule and Upcoming Milestones

Argosy has set clear milestones for completing the Definitive Feasibility Study. Crystallisation testworks are expected to finish shortly, representing an immediate milestone. Following this, the feasibility basic engineering package, underway in Europe, is scheduled for completion by end-September. This measured engineering progression ensures each testwork program informs subsequent design phases, reflecting technical dependencies and optimization based on validated results.

The company’s collaboration with international technology and engineering firms ensures access to expert knowledge and adherence to global standards for the Definitive Feasibility Study. Engagement of lithium process consultants alongside engineering providers demonstrates a professional and comprehensive approach. Progression from solvent extraction to crystallisation and final engineering package development illustrates systematic project advancement. Investors will likely monitor crystallisation completion and the engineering package release as key indicators of project momentum and technical validation.

Lithium Market Context and Project Importance

The Rincon Lithium Project aligns with global lithium demand growth driven by electric vehicle adoption and energy storage needs. Situated in Argentina’s lithium triangle, a premier lithium supply region, the project’s focus on solid lithium chloride production in Stage 1a reflects current market dynamics and capital efficiency requirements. The scalable flowsheet enabling battery-quality product production offers strategic flexibility to meet evolving market demands.

The development strategy’s progression from solid lithium chloride to battery-grade lithium carbonate or hydroxide aligns with market needs and industry best practices. Comprehensive testwork de-risking and infrastructure advantages position Rincon competitively within the global lithium landscape. Engagement of international technology providers and consultants underscores the technical sophistication essential for success. Completion of the Definitive Feasibility Study will mark a key de-risking milestone, potentially facilitating financing and development partnerships.

Process Flowsheet Validation and Risk Reduction Strategy

Argosy’s extensive process flowsheet validation through multiple testwork programs exemplifies a systematic technical risk mitigation approach. Rather than relying solely on theoretical models, the company has invested in pilot-scale and laboratory demonstrations of critical unit operations, providing engineering assurance and validating design assumptions. The absence of major issues across testwork indicates a sound fundamental process approach, with no significant changes anticipated as the project advances toward commercial development.

Sequential validation of operations—from brine pre-concentration to evaporation, solvent extraction, and crystallisation—confirms each process step functions as intended. Achieving 99% lithium chloride purity and 94.4% maximum lithium yield in solvent extraction tests demonstrates reliable attainment of product quality targets. Stable operation during extended pilot testing suggests the process will maintain operational stability at commercial scale. These technical achievements collectively lower execution risks associated with scaling from pilot to full-scale facility construction and operation.