CleanTech Lithium PLC (AIM:CTL, OTCQX:CTLHF) said recent trials of new membrane technology developed by DuPont Water Solutions met or exceeded expectations, supporting the case for more efficient lithium processing at lower cost.
The test work, carried out on eluate from CleanTech’s pilot plant in Chile, showed strong lithium recovery alongside high rejection rates for impurities such as calcium and magnesium.
The nanofiltration (NF) membrane is part of the company’s direct lithium extraction (DLE) process, a method designed to recover lithium from brine without large evaporation ponds. In the trials, lithium recovery reached 94% and 92% across two test runs using eluates of different concentrations.
Calcium and magnesium were removed at rates of 85% and 97% respectively.
CleanTech said the performance was in line with or better than the technical benchmarks set by DuPont.
Notably, the technology remained effective even at higher concentrations, which suggests it could operate at lower input volumes.
That, in turn, could cut both capital and operating costs for future production plants.
CEO Ignacio Mehech said: "These highly encouraging results mark an important step in our collaboration with DuPont Water Solutions.
"Calcium and magnesium are among the most difficult impurities to remove in the lithium extraction process, and DuPont's nanofiltration technology has demonstrated excellent rejection rates while maintaining high lithium recovery.
"This supports our approach to sustainable lithium production and signals the potential for reduced capital and operating costs as we progress towards commercialisation."
The company added that the membranes were tested at a lower pressure than they are designed for, meaning recovery rates could improve further under full operating conditions. Lower reprocessing volumes would also reduce waste and energy use.
CleanTech is developing sustainable lithium production in Chile, a country that holds some of the world’s largest reserves.
Direct lithium extraction is seen as a more environmentally friendly alternative to traditional mining and evaporation methods, particularly in water-sensitive regions such as the Atacama.