Deposit Types
Lithium brine deposits are accumulations of saline groundwater that are enriched in dissolved lithium and other elements. All presently producing lithium brine deposits are referred to as sa lars and share a number of first-order characteristics: (1) arid climate; (2) closed basin contained in a playa or salar; (3) tectonically driven subsidence; (4) associated igneous or geothermal activity; (5) suitable lithium source-rocks; (6) one or more adequate aquifers; and (7) sufficient time to concentrate a brine (Bradley et al., 2013). However, according to Eccles and Berhane (2011) “The source of lithium in oil-field waters remains subject to debate. Most explanations generally conform with models proposed for Li-rich brine solutions that include recycling of earlier deposits/salars, mixing with pre-existing subsurface brines, weathering of volcanic and/or basement rocks, and mobilizing fluids associated with hydrothermal volcanic activity (e.g., Garret, 2004). However, none of these hypotheses has identified the ultimate source for the anomalous values of Li in oil-field waters”.

In a comprehensive investigation of Li-isotope and elemental data from Li-rich oil-field brines in Israel, Chan et al. (2002) suggested that these brines evolved from seawater through a process of mineral reactions, evaporation and dilution. In this case, brines that were isotopically lighter than seawater were associated with lithium mobilized from sediment. Huff (2016; 20 ........

For the Clearwater Lithium Project, lithium is sourced from the production of brine water from deep vertical or deviated wells into the Leduc aquifer. This brine will be transported to the Central Processing Facility (CPF) via underground pipelines where lithium will be extracted from the brine water. Lithium void brine is then returned to the Leduc aquifer through deep vertical or deviated injection wells. There are no surface mining methods utilized for this project as the brine is pumped from the aquifer and returned back into the aquifer after lithium removal, within a closed-loop system. Primary extraction and the recovery of lithium is achieved through direct lithium extraction methods developed by the company and described in detail herein.

Vertical and deviated wells are required for production and injection. Most of the existing wells in the project area are developed as one well from one surface pad. For this project, consideration is given to environmental and surface land use to minimize disturbance and optimize capital costs. Therefore, the development plan is to place multiple wells from one surface pad, referred to as a multi-well pad. This allows for the centralized gathering of fluids and reduced road and pipeline construction. The bottomhole well placement is defined based on the aquifer modeling and assumes spacing between the bottomhole locations. With these targets in mind, the well pads are planned with a series of vertical to directional well ........

The preliminary process design is based on the production of 20,000 tonnes per year lithium hydroxide monohydrate (“LiOH.H2O” or “LHM”) using E3’s proprietary ion exchange (IX) sorbent material, which requires processing of approximately 5,833 m3/h of 74.6 mg/L feed brine. It is estimated to recover =94% of lithium in the feed brine and reagent recycle, producing approximately 2.48 t/h LiOH.H2O.

Primary Lithium Extraction
The feed brine is contacted with and absorbed onto E3’s proprietary sorbent material in a series of “ion exchange” vessels, similar in configuration to a standard Resin-in-Pulp or Carbon-in-Pulp circuit commonly employed in the hydrometallurgical industry. The lithium is stripped from the loaded sorbent using anolyte recycled from the electrolysis circuit while the depleted lithium brine is returned to the well field for re-injection into the aquifer.

Polishing of Lithium Concentrate
The primary ion exchange process provides significant ........