· Fixed duration pump tests completed at Laguna Verde (wells LV05 and LV06) and at Francisco Basin (FB01).
· Pump tests provide key data for hydrogeological models including aquifer transmissivity, which is used to model bore field flow rates for brine extraction in a commercial operation.
· Calculated transmissivity from the LV05 and LV06 pump tests support the bore field flow rates of 30L/s that were modelled in the Laguna Verde scoping study announced in January 2023.
· The FB01 pump test recorded a high transmissivity that corresponds to a modelled flow rate of approximately 80L/s in a well designed for an operation stage project.
· This high flow rate will provide a positive input into the Francisco Basin Scoping Study which is progressing well.
· The first of a two-stage brine reinjection test will commence imminently at Laguna Verde.
· Brine reinjection into aquifers is a key advantage to Direct Lithium Extraction (DLE) operations and CleanTech Lithium is leading the sector in Chile with this test-work.
· An update will be released shortly on the drill programme progress at all three projects, including the laboratory assay results for the 2023 programme at Laguna Verde, the final batch of which is expected to be received next week.
Aldo Boitano, Chief Executive Officer, of CleanTech Lithium PLC, said:
"I am delighted at the progress we are making on our extensive work programmes across our three different basins.
"The pump test results at Laguna Verde and especially at Francisco Basin surpassed expectations and with the commencement of the first-ever reinjection test in Chile just round the corner, this could be a game-changing moment for Chile´s lithium sector, a considerable move forward for the Company and the wider lithium industry to produce lithium with minimal environmental impact; what we refer to as 'green' lithium.
We will provide another update shortly on our drill programme results and progress at all three of our projects, which will be followed by updating the market on JORC upgrades from Laguna Verde, as well as JORC upgrades and the Scoping Study for Francisco Basin."
Positive Results from Pump Test Programmes
CTL is in the process of building a hydrogeological model for the operating stage of the projects that will include the modelling of the extraction bore field. Pump tests provide key data for the hydrogeological model and are important milestones for brine-based resource projects.
At Laguna Verde, fixed duration pump tests were undertaken at LV05 and LV06. The wells are cased with a diameter of 8 inches which constrains the size of the pump and therefore the flow rate used in the pump test. At LV05, a flow rate of 18L/s was used and based on the aquifer response, which is measured by the drawdown in the well and the recovery rate recorded in the well and piezometers located at 50m and 240m from the well, the aquifer transmissivity is calculated. At LV06 the test was run at a flow rate of 14L/s. Both wells recorded >80% recovery within 30 minutes and full recovery within 36 hours.
Based on the flow rate and aquifer response a transmissivity for LV05 and LV06 was calculated as 27.1 m2 and 22.6m2 per day respectively. Based on the calculated transmissivity, the modelled flow rate for a commercial bore with a diameter of 14 inches is expected to be approximately 30L/s. This is in line with the flow rate of extraction bores used in the completed Scoping Study for Laguna Verde, announced in January 2023, providing important confirmation of the projects´ bore field extraction capacity.
Figure 1: LV05 Pump Test in Progress
At the Francisco Basin project, a fixed duration pump test has been completed at FB01, a well cased with a diameter of 8 inches, with a flow rate of 19L/s utilised for the initial test. The aquifer drawdown was minimal and the recovery rate rapid, resulting in a high transmissivity calculation of 226m2 per day. Based on the calculated transmissivity of FB01, the modelled flow rate for a commercial bore with a diameter of 14 inches is expected to be approximately 80L/s. The aquifer at Francisco Basin is formed by multiple sand units confined by clay units, which is geologically interpreted to have a high potential aquifer transmissivity. This is a very positive result, well exceeding expectations, and will feed into the Francisco Basin Scoping Study that is currently advanced, with a comparatively lower number of bores required to extract the required volume of feed brine.
Figure 2: Pictures of FB01 Pump Test in Progress
Reinjection Programme to Commence - The First Reinjection Test in the Chilean Lithium Sector
For a DLE based project, the other key element of the project's hydrogeological model is the reinjection of spent brine into the subsurface aquifers of the basin. At Laguna Verde, and at Francisco Basin, the Company has a dominant tenure position in the basin allowing for extraction and reinjection of brine in different zones of the basin. In the Scoping Study completed for the Laguna Verde project two sites were proposed for reinjection bore fields as shown in Figure 3. The primary basis for site selection is to limit the distance and elevation difference between the reinjection site and the DLE process plant, where spent brine will be pumped from, and a favourable site geology for subsurface sediments that will host the re-injection brine volume while providing a geological separation with the resource area.
The Company´s primary hydrogeology consultant Gestion Ambiental SA (SGA), an international firm which operates across South America, has designed a two-stage brine reinjection test at Laguna Verde with the first stage planned to be undertaken in the coming weeks. This will involve constant flow rate tests at different depths and pressures. Brine from LV06, which is on the east side of the basin, will be injected into well LV05, on the north-west side of the basin in the relative vicinity of the area of the basin where reinjection is planned, as shown in Figure 3. Downhole geophysics have been completed at LV05 and the well is expected to have a representative geology of the planned reinjection site.
Figure 3: Map of Stage 1 Test Bore Versus Planned Reinjection Sites
The second stage consists of long-term tests, in wells located at the planned reinjection site, to provide valid hydrogeological simulations of the brine reinjection operation. This data will provide important data for the hydrogeological model and the project's environmental impact assessment, one of the key final regulatory approvals required for a project. To the Company´s knowledge, this will be the first brine reinjection programme undertaken in the Chilean Lithium sector. Major lithium producer Albemarle recently announced that it would start its first reinjection programme at Salar de Atacama, the world´s largest lithium production site, at the end of this year. CTL aims to continue to be the leader in developing a brine reinjection model, a key to a successful DLE based project, in Chile.
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CleanTech Lithium (AIM:CTL, Frankfurt:T2N, OTC:CTLHF) is an exploration and development company, advancing the next generation of sustainable lithium projects in Chile. The Company's mission is to produce material quantities of battery-grade lithium by 2026, with near-zero carbon emissions with minimal impact on the environment, offering the EV market a green lithium supply solution.
CleanTech Lithium has three prospective lithium projects - Laguna Verde, Francisco Basin and Llamara projects located in the lithium triangle, the world's centre for battery grade lithium production. They are situated within basins entirely controlled by the Company, which affords significant potential development and operational advantages. The projects have direct access to excellent infrastructure and renewable power.
CleanTech Lithium is committed to using renewable power for processing and reducing the environmental impact of its lithium production by utilising Direct Lithium Extraction. Direct Lithium Extraction is a transformative technology which only adsorbs lithium from brine, with higher recoveries and purities. The method offers short development lead times, low upfront capex, with no extensive site construction and no evaporation pond development so there is no water depletion from the aquifer or harm to the local environment.
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