Millennial Lithium (ML.V) has now completed its second pumping test of a production-scale well at its Pastos Grandes lithium project in Argentina. The test was conducted over a period of 23 days in September, and during this 23 day period the average grade of the lithium in the brine that was pumped remained very consistent with an average grade of 482-518 milligram per liter.
The total drawdown of the reservoir was approximately 57 meters (this level was reached after just two days) which is quite a lot, but the recovery rate was very fast as well: it took only 24 days for the brine level to regain its previous level. Additionally, the tested transmissivity results (transmissivity indicates the rate at which the brine moves through the aquifer) indicate a surface area of 40 square meters per day which, according to CEO Abasov, means the aquifer has ‘good potential to sustain long term pumping at 15 liters per second’.
As expected, the highest lithium values were encountered towards the end of the pumping test period (lithium is relatively heavy and ‘sinks’ to the lower levels of a brine) while the magnesium:lithium ratio averaged 5.3, which is excellent.
The data from this new pumping well test provides Millennial Lithium with more details for its upcoming feasibility study which should be completed in the second quarter and will very likely incorporate the data from two new pumping wells on the southern portion of the Pastos Grandes project. Additionally, a new resource estimate is scheduled for publication later this quarter and we expect a substantial resource increase after the most recent exploration results. We expect the total resources to come in at in excess of 4 million tonnes of LCE, but 5 million tonnes shouldn’t be out of reach. In any case, we expect the resource update and feasibility study to re-confirm Millennial’s Pastos Grandes project as one of the better lithium brine projects out there.