CleanTech Lithium has produced lithium carbonate with purity of up to 99.75% Li₂CO₃ from brine at its Laguna Verde project in Chile, advancing technical validation of the proposed direct lithium extraction (DLE) process ahead of definitive feasibility study work.
Pilot-scale trials processed approximately 24 cubic metres of Laguna Verde brine, yielding lithium carbonate with grades ranging from 99.69% to 99.75%. The results were independently analysed by Alex Stewart Laboratory. The programme tested an integrated flowsheet combining direct lithium extraction with downstream purification, designed around the processing route proposed for the commercial operation. The results support the process assumptions used in the project’s pre-feasibility work and will inform engineering for the definitive feasibility study (DFS).
Nanofiltration Demonstrates Lithium Recovery and Impurity Rejection
A nanofiltration stage supplied by DuPont achieved 98.3% lithium recovery during the pilot programme. The system also rejected approximately 99.8% of magnesium and 95% of calcium. Managing these impurities is an important part of lithium processing because elevated magnesium and calcium concentrations can complicate purification and increase reagent requirements. The pilot results provide data on the performance of the proposed flowsheet in separating lithium from these elements.
The programme also demonstrated the recycling of more than 90% of desorption water. Water recovery is a relevant operating parameter for Laguna Verde, which is located in Chile’s arid Andean region.
Pilot Results Support the 15,000-Tonne Production Plan
CleanTech Lithium is developing Laguna Verde around a proposed production rate of approximately 15,000 tonnes of lithium carbonate per year. The latest testing provides technical information for the project’s planned commercial processing configuration. For direct lithium extraction projects, the ability to maintain recovery rates and manage impurities under continuous operating conditions is important to establishing technical and financial viability. Pilot-scale performance must translate into a reliable integrated process, including filtration, water management and downstream purification.
Although the latest programme strengthens the technical basis for Laguna Verde, the results do not eliminate the risks associated with scaling the process to commercial operation. Laboratory and pilot results must be supported by sustained operating performance at the intended production scale.
Definitive Feasibility Study to Define Commercial Requirements
The pilot data will feed into definitive feasibility engineering as CleanTech Lithium advances the project beyond its pre-feasibility stage. Further work will need to establish final capital and operating costs and demonstrate that the proposed process can perform consistently under commercial conditions. The company must also secure financing for construction before Laguna Verde can advance to a commercial operation. The DFS is the next major development milestone as engineering work incorporates the pilot results into the proposed project design. Maintaining lithium recovery close to the 98.3% achieved during pilot testing, while consistently producing specification-grade lithium carbonate, will be an important measure of the commercial process design.
