Scaling challenges and innovations in the COOL+ process

The METALLICO project is making significant strides in transitioning the COOL+ process—an innovative technology utilizing supercritical CO2 to extract lithium from spodumene ore—from laboratory research to pilot-scale implementation. This novel approach aims to drastically reduce the environmental footprint of lithium production, a critical step toward meeting Europe's growing demand for electric vehicle batteries and securing a sustainable domestic supply chain.

During initial small-scale tests for the COOL+ process, the team identified specific fluid dynamic limitations that impacted overall lithium recovery rates. To resolve these operational bottlenecks and maximize extraction efficiency, the system has been completely redesigned around a new, optimized 230L pressure leaching reactor. This advanced vessel is specifically engineered to provide superior mixing capabilities and precise parameter control, ensuring robust continuous operation. Concurrently, necessary chemical adjustments were made during the early calcination stage; specifically, the addition of sodium carbonate successfully improved lithium extraction from the mineral matrix. However, this modification introduced high levels of sodium into the system, rendering the originally planned electrodialysis purification step technically unviable.

In response, the consortium engineered a completely new downstream purification workflow from scratch. This fully dimensioned, cutting-edge process now utilizes reactive silica precipitation, energy-efficient concentration via high-pressure reverse osmosis, and thermal crystallization to selectively isolate battery-grade lithium carbonate. Beyond simply addressing the sodium challenge, this redesigned workflow significantly enhances the overall sustainability of the pilot by minimizing energy consumption and maximizing water recovery. To maximize operational synergy, the entire COOL+ process—encompassing both the upstream high-pressure leaching and the continuous downstream purification train—will be built as a single, fully integrated pilot plant at the CETAQUA facilities in Barcelona, Spain. Bringing the upstream and downstream phases under one roof allows for seamless material transfer, real-time operational adjustments, and provides a much more accurate representation of a future full-scale industrial plant.

With process designs finalized and CETAQUA actively adapting its facilities to house the complete installation, the project has successfully navigated its scaling challenges. The consortium is currently in an active procurement phase, directly contacting suppliers to purchase the required equipment and prepare for the imminent construction and operation of the pilot plant. Ultimately, these engineering milestones bring the METALLICO project one step closer to delivering a commercially viable, eco-friendly solution for the global lithium market.