CleanTech Lithium PLC (AIM: CTL), the London-listed lithium explorer, has completed the drilling at its Laguna Verde and Francisco Basin projects in Chile with received assays at Laguna Verde showing up to 409mg/L of lithium.
The drilling campaign at Laguna Verde was originally scheduled to complete by April this year but it took two months longer because it reached greater drill depths and found increased aquifer thickness, which the company sees as a positive sign for the upcoming JORC resource upgrade. Drilling at the site from 335m to 497m encountered a 43% increase in aquifer thickness over the four wells compared to the geophysics model. The new findings will be included in the JORC resource upgrade which is expected in early July.
The 18 batches of brine from the Laguna Verde project were analysed by the independent laboratory ALS Chile. The four deepest samples from the LV03 incline hole (one of the four holes that were drilled in this part of the programme and the one that reached closest to the Laguna sub-surface) measured grades of between 349mg/L and 409mg/L of lithium. This is a strong indication that higher lithium grades are present directly beneath the Laguna subsurface and could become an important part of future development plans. The average lithium grade from the total of 10 samples collected from LV03 showed an average lithium grade of 245mg/L lithium.Cleantech Lithium’s chief executive Aldo Boitano said, “We are very pleased with the increased aquifer depth encountered and the first batch of brine assays from Laguna Verde, which include a number of high lithium grades which provide an important target for further drilling.”
The eight samples from the LV01 incline hole collected from the same depth showed an average grade of 217mg/L of lithium in the assay.
Positive implications of brine temperature
Another positive from the drilling results is that the temperature of the brine sample reached up to 30.6 degrees Celsius indicating a strong geothermal influence on sub-surface brine. This could potentially reduce the operating costs of the project as well as its environmental footprint.
Other independent testing that is already taking place is an analysis of a 1kg sample of battery-grade lithium produced by laboratory-scale DLE test-work. The company says those results are imminent.
CleanTech Lithium says it expects to update the market in the coming weeks on further results from the cased levels between the surface and the depth of 320m from holes at both its Laguna Verde and Francisco Basin projects. Boitano added that the company is confident this will lead to an upgraded JORC resource at Laguna Verde and a maiden resource at Francisco Basin.
The Laguna Verde project has an existing measured JORC compliant resource estimate of 77,834 tonnes of lithium carbonate equivalent (LCE) which includes the surface resource. Its inferred resource estimate which covers the sub-surface resource is 1.16 million tonnes LCE.
The drilling programme, which started at the Laguna Verde site at the beginning of this year with the aim of upgrading the JORC estimate, will provide the basis for a Pre-Feasibility Study on the project.
