Rio Tinto Explores Innovative ELi Lithium Processing Technology

What is ELi Lithium Processing Technology?

Understanding the Innovative ELi Process

ELi (Electrochemical Lithium) technology represents a significant advancement in lithium processing, utilizing sophisticated electrochemical methods to produce battery-grade lithium hydroxide. Unlike conventional approaches that rely heavily on chemical reagents, the ELi process employs electricity in a specialized chlor-alkali cell to drive the conversion process, effectively replacing bulk reagents with electrical energy.

The technology functions by passing electrical current through a carefully designed electrochemical cell, triggering reactions that convert lithium-containing solutions into high-purity lithium hydroxide monohydrate—a critical ingredient for advanced battery cathodes. This process stands apart from traditional methods by significantly reducing chemical inputs while maintaining exacting quality standards necessary for electric vehicle (EV) battery production.

According to Neometals Managing Director Chris Reed, the ELi technology offers significant operational advantages: "We are confident ELi can be an ideal complement to Rio Tinto's direct lithium extraction (DLE) technologies to further enhance the value of their Tier 1 portfolio."

Key Advantages Over Conventional Methods

The ELi process presents several compelling benefits compared to traditional lithium processing techniques:

• Reduced Chemical Consumption: By substituting electricity for chemical reagents, ELi significantly decreases the volume of chemicals needed in lithium hydroxide production.

• Enhanced Environmental Profile: The process generates fewer waste streams and has a smaller environmental footprint than conventional chemical-intensive methods.

• Operational Cost Reduction: Preliminary assessments indicate potential for lower operating expenditures, particularly in regions with competitive electricity pricing.

• Process Simplification: ELi offers a more streamlined production pathway with fewer processing steps.

• Superior Product Consistency: The electrochemical approach provides precise control over reaction conditions, potentially yielding more consistent battery-grade output.

• Flexible Deployment: The modular nature of electrochemical cells allows for scalable implementation and potentially easier capacity expansions.

The electrochemical approach also eliminates several environmental challenges associated with traditional processing, including the handling of large volumes of sodium sulfate waste—a common byproduct of conventional conversion methods. This aspect is particularly significant as battery manufacturers and automakers increasingly scrutinize their supply chains for environmental performance.

How is Rio Tinto Exploring This Technology?

The Rio Tinto-RAM Partnership

Rio Tinto has formally entered into a non-binding memorandum of understanding (MOU) with Reed Advanced Materials (RAM) to investigate the commercial potential of ELi technology. This eight-month agreement, which commenced in June 2025, represents a strategic exploration phase to evaluate how the innovative processing method might enhance Rio Tinto's expanding lithium portfolio.

RAM brings significant expertise to the partnership as a specialized joint venture between Neometals (70%) and Mineral Resources (30%)—two companies with established credentials in lithium processing innovation. The MOU establishes a structured framework for collaboration while protecting both parties' interests through enforceable provisions around confidentiality and intellectual property.

Chris Reed expressed enthusiasm about the collaboration: "We are naturally excited to collaborate with Rio Tinto to explore the potential to bring this technology closer to market." This sentiment underscores the potential significance of pairing Rio Tinto's resource base with RAM's processing innovation.

The agreement reflects Rio Tinto's strategy of evaluating emerging technologies before making substantial commitments—a prudent approach given the capital-intensive nature of lithium processing facilities and the evolving technology landscape in battery materials.

Testing and Validation Efforts

The collaboration between Rio Tinto and RAM encompasses several key technical workstreams:

• Process Optimization: Comprehensive laboratory testing to refine operational parameters and maximize conversion efficiency.

• Design Criteria Updates: Revisions to existing process models based on Rio Tinto's specific brine chemistry profiles.

• Demonstration Plant Planning: Preliminary engineering and design work for a potential demonstration-scale facility.

• Argentina Integration Studies: Specific evaluations of how ELi technology might be implemented at Rio Tinto's Argentinian lithium brine insights assets, including the Rincon project.

• Extended Operational Trials: Longer-duration testing to validate process stability and product quality consistency.

These initiatives are designed to systematically advance the technology's readiness level while identifying and addressing any potential implementation challenges. The validation work leverages Rio Tinto's extensive experience in mineral processing scale-up and RAM's specialized knowledge of electrochemical lithium conversion.

A particularly significant aspect of the collaboration is the focus on Argentina as a potential implementation site, which aligns with Rio Tinto's growing presence in the lithium-rich region known as part of South America's "Lithium Triangle."

What Results Have Been Achieved So Far?

Successful Pilot Testing

RAM has already demonstrated promising results using Rio Tinto's Rincon brines with the ELi process. During extensive trials conducted throughout 2023 and 2024, the technology achieved several important milestones:

• Brine Purification: Successful pre-treatment and purification of lithium-containing solutions derived from Rio Tinto's Rincon resource.

• Extended Electrolysis Operations: Completion of a 1,000-hour continuous pilot electrolysis campaign, demonstrating process stability over sustained operation.

• High-Quality Product Synthesis: Production of battery-grade lithium hydroxide monohydrate crystals meeting stringent purity requirements for EV applications.

• Process Integration Validation: Confirmation that ELi technology can effectively process output streams from direct lithium extraction (DLE) operations.

These achievements represent significant technical validation points, particularly the extended 1,000-hour pilot operation. In electrochemical processes, long-duration testing is crucial for evaluating electrode durability, membrane performance, and overall system reliability—factors that directly impact commercial viability.

The successful processing of Rincon brines specifically is noteworthy, as it demonstrates the technology's compatibility with Rio Tinto's actual lithium resources rather than idealized laboratory solutions.

Technical Validation Progress

The technical validation completed to date has yielded valuable insights regarding the process's commercial potential:

• Scale-Up Parameters: The pilot testing has established critical operational data needed for engineering larger systems.

• Product Specification Conformance: Analysis confirms the lithium hydroxide monohydrate produced meets battery manufacturers' strict purity requirements.

• Process Stability Indicators: The extended operation has provided confidence in the robustness of key components like membranes and electrodes.

• Energy Consumption Profiles: Pilot operations have generated actual energy usage data critical for economic assessments.

• Operational Controls Refinement: Testing has allowed for optimization of control systems and operating protocols.

These technical achievements collectively advance the technology's readiness level, providing Rio Tinto with substantive data for evaluating potential commercial implementation. While full commercial validation requires additional steps, the results to date represent essential building blocks toward that goal.

The validation work particularly focuses on product quality consistency—a critical consideration for battery manufacturers who require exceptionally pure lithium compounds with minimal batch-to-batch variation.

How Does ELi Complement Direct Lithium Extraction?

Synergies with Rio Tinto's DLE Technologies

According to Neometals Managing Director Chris Reed, the ELi process offers natural synergies with Rio Tinto's direct lithium extraction (DLE) technologies: "We are confident ELi can be an ideal complement to Rio Tinto's direct lithium extraction technologies to further enhance the value of their Tier 1 portfolio."

This complementary relationship stems from several technical factors:

• Sequential Processing: DLE technologies excel at selectively extracting lithium from brines, while ELi provides an efficient method to convert the concentrated lithium solution into battery-grade lithium hydroxide.

• Chemistry Compatibility: The output from DLE processes—typically lithium chloride solutions—serves as an ideal feedstock for the ELi electrochemical process.

• Shared Infrastructure: Both technologies can potentially share utilities, brine handling systems, and site infrastructure, creating operational efficiencies.

• Integrated Control Systems: Modern automation can enable seamless operation between extraction and conversion stages, optimizing overall performance.

• Water Management: Both processes can be designed with water recycling in mind, a critical consideration in the arid regions where many lithium resources are located.

The potential integration of these technologies represents a more holistic approach to lithium production, addressing both the extraction and conversion challenges that have traditionally required separate specialized processes.

Creating an Integrated Lithium Value Chain

By exploring both DLE and ELi technologies, Rio Tinto appears to be developing a more comprehensive approach to lithium production that could potentially transform their position in the battery materials supply chain:

• Vertical Integration: The combination would enable Rio Tinto to control the process from brine extraction through to battery-grade chemical production.

• Streamlined Logistics: An integrated operation eliminates transportation of intermediate products between separate extraction and conversion facilities.

• Consistent Quality Control: Managing the entire process allows for better quality assurance throughout the production chain.

• Optimized Capital Efficiency: Integrated facilities typically require less total capital than separate extraction and conversion plants.

• Reduced Environmental Footprint: A holistic approach enables more efficient resource utilization, particularly regarding water and energy.

This integrated strategy aligns with broader industry trends toward more efficient, environmentally sustainable lithium production methods. As battery manufacturers increasingly scrutinize their supply chains, producers with advanced, low-impact processing technologies may gain competitive advantages.

The integration of DLE and ELi could potentially position Rio Tinto to produce lithium hydroxide with lower carbon intensity and reduced chemical consumption compared to conventional approaches—attributes increasingly valued by EV manufacturers focused on total supply chain sustainability.

What Are the Potential Commercial Applications?

Market Opportunities for ELi Technology

If successfully commercialized, ELi technology could address several significant market needs in the rapidly evolving lithium sector:

• Battery-Grade Lithium Hydroxide Production: The primary application remains the production of high-purity lithium hydroxide monohydrate for advanced battery cathodes, particularly nickel-rich NMC and NCA formulations preferred by many EV manufacturers.

• Brine Resource Valorization: The technology could enhance the economic viability of lower-concentration lithium brines by providing a more cost-effective conversion pathway.

• Environmentally Differentiated Supply: As battery makers increasingly seek materials with lower environmental footprints, ELi's reduced chemical consumption could create marketing advantages.

• Retrofit Opportunities: Existing lithium producers might consider implementing ELi technology to upgrade or replace conventional conversion circuits.

• Remote Operations: The relatively smaller footprint and reduced reagent requirements could make ELi suitable for implementation in remote locations where logistics for chemical deliveries are challenging.

The technology appears particularly well-suited for the growing segment of lithium hydroxide demand driven by high-nickel cathode chemistries. These advanced battery formulations require exceptionally pure lithium hydroxide and represent the fastest-growing segment of the lithium market due to their higher energy density advantages for EVs.

Scaling Considerations

The partners face several critical considerations when evaluating commercial scale-up potential:

• Capital Intensity: While potentially offering operating cost advantages, electrochemical processes typically require significant upfront investment in specialized equipment.

• Energy Requirements: The electrochemical approach shifts resource consumption from chemical reagents to electricity, making power cost and availability critical factors.

• Membrane and Electrode Durability: Long-term performance of these key components significantly impacts maintenance costs and operational reliability.

• Integration Complexity: Implementing ELi alongside existing DLE systems requires careful interface engineering and process control.

• Market Timing: The partners must consider how quickly the technology can be scaled relative to projected lithium market supply challenges.

• Competitive Landscape: Several alternative lithium processing technologies are under development, creating a dynamic competitive environment.

The commercialization pathway would likely involve a staged approach, potentially beginning with a demonstration plant in Argentina before committing to full commercial scale. This methodical approach aligns with industry best practices for novel process technologies, especially in the capital-intensive mining sector.

Successful commercialization would also depend on the technology's ability to consistently meet the increasingly stringent quality specifications required by battery manufacturers, who typically require extensive qualification testing before accepting new material sources.

What's Next for the Rio Tinto-RAM Collaboration?

Planned Development Pathway

The current MOU outlines a structured pathway for advancing the ELi technology toward potential commercial implementation:

• Initial Assessment Phase: The eight-month agreement period focuses on evaluating the technology's fundamental compatibility with Rio Tinto's resources and strategic priorities.

• Design and Engineering Work: If initial assessments prove promising, the collaboration may progress to detailed engineering for a demonstration plant.

• Cost Estimation: Comprehensive capital and operating cost models will inform economic feasibility evaluations.

• Argentina Deployment Planning: The partners are specifically examining implementation at Rio Tinto's Argentinian assets, leveraging the company's established presence in the region.

• Extended Trial Programs: Further piloting would likely focus on continuous operation with actual Rio Tinto brines to validate long-term performance.

• Strategic Partnership Formalization: Successful validation could lead to more formal commercial arrangements between the parties.

This staged approach reflects standard industry practice for evaluating and scaling new process technologies, particularly in the conservative mining sector where capital deployment decisions undergo rigorous scrutiny.

The explicit mention of Argentina suggests Rio Tinto may be considering ELi technology specifically for its Rincon project, which the company acquired in 2022 for $825 million, demonstrating its commitment to building a significant lithium business.

Timeline and Decision Points

While specific timelines beyond the initial eight-month MOU period haven't been disclosed, several key decision points will likely shape the collaboration's progression:

• Technical Validation Milestones: Completion of optimization testwork and verification of process performance with Rio Tinto's specific lithium resources.

• Economic Assessment Thresholds: Determination that the technology can meet Rio Tinto's internal investment criteria regarding return on capital, operating margins, and risk profile.

• Strategic Alignment Evaluation: Confirmation that ELi technology complements Rio Tinto's broader lithium strategy and market positioning.

• Implementation Readiness Assessment: Verification that the technology is sufficiently mature for larger-scale deployment with acceptable technical risk.

• Partnership Structure Decisions: Determination of the optimal commercial arrangement between Rio Tinto and RAM for potential technology implementation.

The agreement's provision for extension or termination by mutual consent provides flexibility for both parties as these evaluations progress. This approach allows for responsive decision-making based on emerging technical and market developments.

Industry experience suggests that commercializing new lithium processing technologies typically requires 3-5 years from pilot testing to commercial operation, indicating that commercial implementation—if pursued—would likely occur in the 2027-2029 timeframe.

How Does This Fit Into Rio Tinto's Lithium Strategy?

Expanding Rio Tinto's Lithium Portfolio

Rio Tinto has been methodically building its presence in the lithium sector, recognizing the mineral's critical role in energy transition technologies. The exploration of ELi technology represents another strategic element in the company's expanding lithium business:

• Resource Diversification: Rio Tinto has acquired multiple lithium assets, including the Rincon project in Argentina and the Jadar project in Serbia, establishing a global footprint in key lithium provinces.

• Technology Differentiation: By evaluating innovative processing methods like ELi, Rio Tinto is positioning itself at the technological forefront of lithium production.

• Value Chain Integration: The combination of resource ownership and advanced processing capabilities could enable Rio Tinto to capture more value from its lithium assets.

• Market Positioning: Developing lower-impact production methods aligns with Rio Tinto's broader sustainability commitments and could appeal to environmentally conscious customers.

• Portfolio Optimization: The company appears to be building a lithium business that complements its existing strengths in large-scale resource development and processing.

This strategic approach reflects Rio Tinto's traditional focus on developing tier-one assets with long production lives and competitive cost positions. The company's interest in ELi technology suggests it sees potential for processing innovations to enhance the value proposition of its lithium resources.

The deliberate pace of Rio Tinto's lithium strategy—methodically evaluating technologies before making major commitments—aligns with the company's disciplined approach to capital allocation in a sector that has experienced significant price volatility.

Positioning in the Battery Minerals Market

By investing in innovative processing technologies like ELi, Rio Tinto is positioning itself as a forward-thinking player in the rapidly evolving battery minerals landscape:

• Premium Product Focus: The emphasis on high-purity lithium hydroxide production targets the highest-value segment of the lithium market.

• Sustainability Differentiation: Lower-impact processing methods could help distinguish Rio Tinto's lithium products in a market increasingly focused on environmental credentials.

• Long-Term Customer Relationships: Developing advanced processing capabilities could support Rio Tinto's efforts to establish strategic partnerships with battery manufacturers and automakers.

• Technology Leadership: Early involvement with innovative technologies like ELi could provide competitive advantages as the lithium industry matures.

• Value-Added Processing: Moving beyond simple concentration to produce battery-grade chemicals represents a higher-margin business opportunity.

This strategy positions Rio Tinto to potentially capture a larger share of the value chain in battery materials, moving beyond its traditional role as primarily a resource provider. The approach aligns with broader industry trends toward greater integration between mining and chemical processing in the battery materials sector.

Rio Tinto's methodical approach to technology evaluation also reduces risk in an industry where processing technologies are still evolving rapidly, allowing the company to benefit from innovation while managing

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