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; 2019) suggests that Li-brine in the Nisku and Leduc formations are the result of “preferential dissolution of Li-enriched late-stage evaporite minerals, likely from the middle Devonian Prairie Evaporite Formation, into evapo-concentrated late Devonian seawater”, followed by downward brine migration into the Devonian Winnipegosis Formation and westward migration caused by Jurassic tilting. Finally, during the Laramide tectonics, the brine was diluted by meteoric water driven into the Devonian of the southwestern Alberta Basin by hydraulic gradients.

It has also been theorized that the source of lithium enriched brines is associated with the magnesium-rich fluids responsible for pervasive dolomitization in the Leduc Formation. Stacey (2000) proposes these deep basinal brines migrated from the Prairie Evaporite into regional aquifers and were emplaced in part via large faults. Alternatively, the “reflux” dolomitization model proposed by Potma et. al. (2001), in whichevapo-concentrated Nisku-aged fluids are responsible for wide-spread dolomitization across the Leduc in Bashaw and Meadowbrook Rimbey, would suggest the lithium is potentially sourced from the later Devonian Nisku sea.

Lithium brines associated with oil wells have been known for some time, but are typically lower in grade when compared to the major lithium deposits of the world; Salar de Atacama, Chile (site of production facilities of the two major producers Albemarle and SQM), Salar de Hombre Muerto in Argentina (home of the third major producer FMC) and Clayton Valley, USA (Owned by Albemarle, and the only lithium production facility in North America). These existing sites use surface evaporation pools as part of the lithium concentration process. The recent advent of new dissolved metal recovery technologies and methods has made lower grade brines economically viable.

Mineralization
The potential for lithium-enriched brine in the Devonian petroleum system of Alberta was initially identified by Hitchon et al. (1995). Potential aquifers were located in reef complexes of the Woodbend and Winterburn groups. Subsequent work by Eccles and Jean (2010), Huff et al. (2011, 2012) and Huff (2016) confirmed the presence of elevated Li (e.g., >75 mg/L Li) in aquifers associated with the Devonian reef complexes.

The main lithium accumulations in E3 Metals’ properties occur within brines contained within dolomitized reefs of Devonian Leduc age, with a secondary accumulation occurring at a higher elevation in the biostromal development in the Nisku Formation of the Devonian Winterburn Group. Consequently, Li-brine mineralization in the Project area consists of Li-enriched Na-Ca brines that are hosted in porous and permeable aquifers associated with the Devonian carbonate reef complexes.

Li-brine wastewater is associated with oil and gas production. The Devonian petroleum system region represents a mature petroleum field and today, most, if not all of the wells produce far more water than petroleum products. Many of the wells in this area in their early history started out at hundreds to thousands of barrels per day of petroleum products and required little active pumping to extract. However, at present most of the wells produce excessive amounts of formation water in comparison to petroleum products. Formation water production in the CCRA averaged approximately 1,600 m3/day over the last 5 years (AccumapTM, 2020).

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 wells with varying degrees of deviation. This is a common drilling practice utilizing special tools for directional drilling. Below is a diagram showing variations of directional drilling well (hole) displacement. There are no plans for horizontal wells for this project, as they would not provide sufficient vertical coverage for optimized brine recovery from the thick Leduc aquifer.

The lithium enriched brine in the Leduc aquifer is produced through the subsurface wells to surface, using a downhole pumping system. The pumping to surface is referred to as ‘Artificial lift’, which is required to overcome the weight of the water column to surface, even with the support of the aquifer flowing pressure. The pumping system planned for this project is Electrical Submersible Pumps (ESP). They are commonly used where large fluid volumes are pumped for industrial purposes, including oil production and geothermal operations.

The pumps consist of multiple centrifugal pump stages mounted in series within a housing attached to a submersible electric motor. Each stage contains a rotating impeller and stationary diffusers typically cast from high-nickel iron to minimize abrasion or corrosion damage.

The ESP design planned for this project will move the brine from the Leduc aquifer depth of over 2500m to surface and maintain sufficient pressure to flow into the gathering pipeline system to the central Lithium recovery facility. The pumps are set above the producing interval, based on the expected aquifer flowing pressure and rate. The fluid from the producer wells will have sufficient pressure to flow directly to the Central processing facility (CPF), with metering on the multi-well pad facility. The selected Pump size is 171.45 mm (6.75”) and are 1,029 Horsepower with a discharge pressure of 17,886 kPa.

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 ........