Atacama Water was contracted to act as a ‘Qualified Person’ for the lithium resource and reserve estimation work. This involved execution of more than 40 exploration holes, production wells, piezometer installations as well as numerous in-depth hydrogeological field investigations to support the development of the conceptual hydrogeological model for Salar de Maricunga. More specifically, the work included:
- Defining the three-dimensional distribution of lithium concentrations and hydraulic parameters in the Salar
- Locating the brine/freshwater interface
- Characterising the local wetland systems
- Quantifying recharge and discharge mechanisms
- Developing a water balance
The latest NI 43-101 resource estimate includes more than two million tonnes of Measured and Indicated Resources of LCE. In addition to the work performed by Atacama Water, DHI built, calibrated and operated a FEFLOW numerical groundwater flow and transport model to:
- Simulate the brine production from the Salar
- Evaluate potential environmental effects to support the project’s environmental impact assessment (EIA)
- Estimate the lithium brine reserves
The FEFLOW groundwater model included dynamic evaporation, solute mass transport and implementation of different tracers to fully characterise the origin of the LCE mobilised by the operation of the mine. In addition, the model was used as an optimisation tool to identify the best locations for the pumping wells in order to minimise possible environmental impact.
Results of these model simulations indicate sufficient LCE reserves to support an annual production of 20,000 tonnes over a 20-year project life.