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CleanTech Lithium PLC (AIM: CTL, Frankfurt: T2N) has successfully produced approximately 330kg of high purity lithium carbonate by processing eluate from its Direct Lithium Extraction (DLE) pilot plant in Chile. Collaborating with USA-based Empower EIT, the company processed 55,000 litres of eluate at a Dallas, Texas facility, with laboratory tests confirming lithium carbonate purity between 99.68% and 99.91% across five production campaigns. This achievement marks a significant step toward the definitive feasibility study for the Laguna Verde project, one of CleanTech Lithium's two primary lithium assets in Chile's lithium triangle.
Key Points
- CleanTech Lithium PLC (AIM: CTL) produced high purity lithium carbonate from its DLE pilot plant eluate in partnership with Empower EIT.
- Approximately 330kg of lithium carbonate was generated, with the final batch reaching 99.91% purity, independently verified by Benchmark Laboratory in Houston.
- 55,000 litres of eluate were processed at Empower's 1600 square-metre Dallas, Texas facility between March and May 2026; an additional ~250kg of lithium carbonate remains stored in recycle fluids.
- Ongoing optimisation includes a pilot programme in Santiago, an adsorbent trial in France, and spent brine reinjection analysis with Zelandez.
Dallas Pilot Facility Confirms Viability of High Purity Lithium Carbonate Production
Through its collaboration with Empower EIT, CleanTech Lithium converted eluate from the Laguna Verde DLE pilot plant into battery-grade lithium carbonate. The processing campaign, conducted from March to May 2026 at Empower's advanced Dallas, Texas facility, handled 55,000 litres of eluate derived from brine at the company's pilot plant in Copiapó, Chile. The 1600 square-metre facility offers a comprehensive US-based lithium processing solution. The trial aimed to demonstrate consistent, reliable downstream conversion of eluate into commercially viable lithium carbonate.
Results validated the downstream processing method's technical feasibility. Five carbonation batches were completed, with Benchmark Laboratory in Houston independently confirming purity levels ranging from 99.68% to 99.91%. The final batch achieved the highest purity of 99.91%, surpassing the 99.7% purity threshold under optimised continuous operation. Additionally, the carbonation stage produced lithium-rich permeate retained in recycle fluids, storing approximately 250kg of lithium carbonate for potential recovery.
Advanced Nanofiltration and Boron Removal Enhance Process Efficiency
Empower's downstream process integrated DuPont™ FilmTec™ LiNE-XD 4040 nanofiltration membranes, significantly improving purification by removing calcium and magnesium impurities essential for battery-grade lithium carbonate production. Following nanofiltration, an ion-exchange stage eliminated about 97% of boron, the main contaminant in post-DLE processing, under optimised continuous conditions. CleanTech Lithium is assessing the potential commercial recovery of boron as a by-product to improve project economics.
The process operated continuously through nanofiltration and ion-exchange before switching to batch carbonation. Residual boron after ion-exchange underwent thermal evaporation and final polishing to meet purity requirements. This multi-stage approach effectively controlled impurities such as sodium, potassium, boron, nickel, chloride, silicon, and sulphur across all batches, with the final batch showing zero sodium and potassium.
Santiago Pilot Programme Validates DLE Parameters and Membrane Technology
Complementing Dallas results, CleanTech Lithium is conducting a pilot programme with Xian Lanshen New Material Company (Lanshen) in Santiago, Chile, to optimise and confirm DLE process parameters from the Laguna Verde Pre-Feasibility Study (PFS). The programme processes 20 cubic metres of fresh brine from Laguna Verde across three stages: DLE parameter verification, advanced membrane and purification evaluation, and final carbonation producing lithium carbonate meeting Chinese battery-grade standards.
The first stage confirmed DLE parameters, and reports on the second stage’s membrane and purification evaluation have been received. The ongoing final stage focuses on carbonation and includes producing a 5kg lithium carbonate sample for external testing. Results will be shared upon completion, further validating Laguna Verde’s technical and metallurgical basis. Running this Chilean pilot alongside the Dallas trial exemplifies CleanTech Lithium’s multi-faceted approach to de-risking downstream processing.
French Adsorbent Benchmarking Trial to Optimise DLE Technology Selection
CleanTech Lithium has engaged Hephaistos Insights in France to conduct an extensive adsorbent trial and DLE benchmarking study using Laguna Verde brine. Starting soon after material transfer, this definitive feasibility study-level assessment includes detailed eluate analysis tailored to the company’s brine chemistry. Seprosys SAS will perform bench-scale testing.
The trial will evaluate multiple adsorbents, including CleanTech Lithium’s current reference and alternatives from North American and European suppliers. Focus will be on elution efficiency, a key factor in lithium recovery quality and quantity during DLE. Advanced chromatography will enable precise automatic column effluent analysis, guiding optimal adsorbent selection to reduce technical risk ahead of definitive feasibility study progression.
Zelandez to Lead Spent Brine Reinjection Study for Environmental Sustainability
CleanTech Lithium has appointed Zelandez, a lithium brine services leader, to perform a comprehensive spent brine reinjection options analysis for Laguna Verde. This study supports the company’s commitment to environmentally sustainable DLE development by evaluating aquifer reinjection concepts and brine management strategies.
Zelandez’s multidisciplinary team of hydrogeologists, reservoir engineers, and DLE experts will deliver a technical assessment integrating basin dynamics, environmental permitting, and cost modelling. The outcome will recommend definitive feasibility study workplans, advancing Laguna Verde toward sustainable commercial development. This reinjection approach differentiates CleanTech Lithium’s DLE method by offering higher recoveries and shorter lead times versus traditional evaporation pond lithium production, while avoiding extensive evaporation infrastructure.
Laguna Verde Advances Toward Definitive Feasibility Study Following PFS
Laguna Verde is one of CleanTech Lithium’s two main lithium development projects in Chile’s lithium triangle, a global hub for battery-grade lithium. The project has completed a Pre-Feasibility Study, with ongoing pilot and optimisation programmes designed to inform and mitigate risks for the definitive feasibility study. CleanTech Lithium and Chile’s Mining Ministry have agreed contractual terms for the Special Lithium Operating Contract (CEOL), pending final government ratification.
This phase marks a systematic shift from early piloting to advanced development. CEO Ignacio Mehech highlighted the milestone achieved with Empower and the range of test-work building on the PFS as the project moves toward definitive feasibility. The concurrent Dallas eluate processing, Santiago pilot, French adsorbent study, and spent brine reinjection analysis demonstrate a thorough approach to validating technical, environmental, and economic aspects before full feasibility assessment.
Direct Lithium Extraction Positions CleanTech Lithium Competitively in Global Market
CleanTech Lithium’s focus on Direct Lithium Extraction technology sets it apart in the lithium sector by enabling higher brine recovery rates, shorter development timelines, and eliminating the need for large evaporation ponds. These advantages address operational and environmental challenges common in water-scarce regions like Chile’s Atacama Desert where the company operates.
Located in the lithium triangle, the Laguna Verde and Viendo Andino projects are strategically positioned in a leading battery-grade lithium production region. The Dallas pilot’s successful high purity lithium carbonate production, alongside ongoing optimisation, equips CleanTech Lithium to compete in a market where battery-grade lithium carbonate commands premium pricing. The company’s third asset, Arenas Blancas in Salar de Atacama, remains in early exploration. Combined with DLE technology and multiple projects at different stages, CleanTech Lithium holds diversified opportunities in the lithium industry.
Competent Person Verification and Independent Lab Confirm Purity Results
The announcement was prepared and approved by Marcelo Bravo, a qualified Competent Person under AIM and JORC Code 2012 standards. Mr Bravo holds degrees in Chemical Engineering and Mineral Processing, currently serves as Senior Process Consulting Engineer at Ad-Infinitum, and has extensive experience in lithium and potassium carbonate production across South America. He is registered under Chilean law with Competent Person number 412 and has reviewed the technical content.
Purity results were independently verified by Benchmark Laboratory in Houston, USA, an external third-party testing facility. This verification assures the accuracy and reliability of lithium carbonate purity across all five production batches. Detailed composition data for calcium, magnesium, sodium, potassium, boron, nickel, chloride, silicon, sulphur, and phosphorus are provided for investor review.
This article is for general informational purposes only and does not constitute investment advice. It is based solely on facts disclosed in CleanTech Lithium PLC’s announcement dated 24 July 2026. Exploration and development-stage mining companies carry significant technical, regulatory, financial, and market risks. Share price performance is not guaranteed, and past results do not predict future outcomes. Investors should seek independent financial advice before making investment decisions. The announcement contains forward-looking statements subject to risks and uncertainties.
