Modeling Lithium Brine Re-Injection for a DLE Brine Operation at the Salar de Atacama

Alex Grant, Principal, Jade Cove Partners, San Francisco, USA

Gene Morgan, CEO, Zelandez, Santa Cruz, Bolivia

March 2021

The PDF of this article is available here and its associated LinkedIn post is available here.

Hydrological issues associated with brine extraction to produce potash and lithium at the Salar de Atacama in Northern Chile are complex, but often over-simplified as “water unavailability”. There are aspects to the situation that are logistical, political, economic, environmental, and commercial, but there is one central feature of the “drama in the Atacama” which is technical. That feature is the concern that brine extraction with evaporative processing that removes the water of the brine from the basin’s aquifers could cause imbalances in the hydrology of the basin, impacting the stability of lower salt content lagoons at the periphery of the salar. (1, 2)

But if brine extraction operators in the Salar de Atacama could extract lithium from brine without evaporating most of the water, leaving potash in the brine, could the brine be re-injected back in the ground in a way that does not disrupt water tables? This could be enabled by a direct lithium extraction (DLE) technology solution. We have published multiple articles on this topic in the last year with differentiated perspectives focused on technical solutions to technical aspects of the lithium brine hydrology and extraction. (3, 4)

Zelandez has led a group of like-minded folks who share an interest in the technical aspects of the problem to understand how a DLE and brine re-injection strategy might work in the Salar de Atacama. This particular site for our studies was chosen because it is by far the most scrutinized lithium brine extraction site in the world, is the source of most lithium from brine, and as a result also has the most public hydrology data associated with it. That group includes:

Leonard Zourek, a Masters student at ETH Zurich in Switzerland. He wrote a chapter of his thesis on Salar de Atacama brine re-injection hydrology, building his own MODFLOW models using public data. The focus of his work was to understand if depletive brine extraction in the salar nucleus would eventually lead to brine levels dropping near sensitive lagoons.

Steve Shikaze and Steve Murray, expert hydrology modelers who build hydrology models for a living for lithium brine operations at Matrix Solutions. The focus of their work was to understand the dynamics of fresh & spent brine mixing after lithium was removed using a DLE technology and brine re-injected, and to see if that mixing might cause issues for a DLE operation.

With their permissions, we are publishing the products of their high-level models here for free and in full. Our intention for doing this is that the frameworks and ways of thinking demonstrated in these models may be helpful for developing preliminary understandings of what is possible for lithium brine development in South America and beyond. These studies should be considered preliminary and academic, but are also specific enough that they show where strings might be pulled to unravel more sophisticated insights via more detailed modeling.

There is nothing inherently “wrong” with evaporative brine processing as long as water availability for plants, animals, and humans is not impacted. However, there is significant interest in applying DLE to brine operations across the Lithium Triangle, and we hope that these models will provide helpful starting points for thinking about spent brine re-injection to either protect sensitive ecosystems, or at least prevent fresh and spent brine from mixing, as this could hurt project economics. We invite constructive feedback.

The reports on these modeling projects can be found in full and unredacted in the PDF document referenced above.

Acknowledgements

Thank you to Leonard Zourek of ETH Zurich, Steve Shikaze of Matrix Solutions, and Steve Murray of Matrix Solutions for their time and energy focused on understanding the solutions to these interesting and complex challenges. Thank you also to Zelandez team members Fernando Lourenco and Murray Brooker.

References

(1)   Grant, 2020. Is Lithium Brine Water? URL.

(2)   Grant, Hersh, et al., 2020. “Is Lithium Brine Water?” – The Anti-Webinar. URL.

(3)   Grant, Morgan, 2019. Re-Injection Enhanced Production for Direct Lithium Extraction (DLE) Projects. URL.

(4)   Grant, Barros, 2020. Chile’s Lithium Industry May Need a Tech Upgrade. URL.