South West Arkansas Project — 2025 Technical Report

This technical report presents the proposed lithium recovery process for a planned brine-to-battery-quality lithium carbonate facility in southwest Arkansas.

Report context

Dated October 14, 2025, this NI 43-101 Technical Report and Definitive Feasibility Study describes the proposed South West Arkansas Project, which would extract lithium-rich brine from the Smackover Formation and process it to battery-quality lithium carbonate at a central processing facility (CPF).

Processing route

Overview of recovery method

Lithium-rich brine would be extracted from brine supply wells and transported via pipeline to the CPF for lithium extraction and subsequent processing into lithium carbonate. The brine production system at the well pad facilities comprises three-phase separation of brine, gas, and oil using a dedicated separator; transfer of separated raw brine to the CPF using centrifugal pumps; cooling of separated sour gas via an air-cooled gas cooler, followed by separation of the liquid phase in a two-phase separator; and recirculation of condensed liquids to the three-phase separator through dedicated pumping systems.

Lithium-depleted brine from the CPF would be returned to the well pad facilities via pipeline for injection. The injection system includes high-pressure injection pumps that reinject the lithium-depleted brine into the subsurface reservoir through designated injection wells. Sour gas separated at the well pads would be conveyed via pipeline to a nearby third-party facility for appropriate reinjection or treatment.

The lithium recovery method within the Project facility consists of four major process blocks: brine pre-treatment, direct lithium extraction, concentration and purification, and lithium carbonate conversion.

Wellfield design

Production well system. The production well system utilizes an electric submersible pump (ESP) to pump lithium-rich brine from the Smackover Formation approximately 2,600 to 2,900 m (8,500 to 9,400 ft) below mean sea level or approximately 1,200 m (4,000 ft) below grade to the wellhead at the surface. The ESP is a vertical, multi-stage, centrifugal pump with built-in vapour liquid separation capabilities to degas the brine as it is pumped to the surface. Sour gas dissolved in the brine at reservoir conditions is liberated as static pressure drops on the way to the surface; the separated sour gas travels up the annular space between the production tubing and well casing until it reaches the wellhead, where the gas is captured and sent to a third party oil and gas operator for disposal via existing gas injection infrastructure.

Three-phase separator. Lithium-rich brine from the discharges of each production ESP on the well pad is comingled and transferred to the pad three-phase separator, which provides residence time for brine, oily waste, and any remaining sour gas to separate. The brine from the production wells collects as the dense aqueous liquid phase at the bottom of the vessel. Brine booster pumps are centrifugal pumps equipped with a variable speed drive and are used to maintain level in the three-phase separator and boost the pressure as required to transfer the brine from each well pad to the CPF. A series of pack plates are installed in the separator to improve coalescing of the lower density oily waste to form a thin organic layer that sits on top of the brine phase. The oily waste phase overflows a weir into the oil container where it is collected for removal. The remaining sour gas in the production fluid flashes off in the separator, exits out the top of the vessel, and is then sent to the sour gas cooler.

Sour gas system. Sour gas from each of the production wells on the pad and from the three-phase separator is collected and sent to a sour gas cooler, which condenses water and any light hydrocarbons for removal. This process step reduces condensation, and subsequently corrosion, in the pipeline and increases the density of the gas which reduces the pipe sizes required between the well pads and the end user. The cooled sour gas and condensed water then pass from the cooler to a two-phase separator, where the condensed liquid is separated and collected prior to the sour gas entering the pipeline. The condensate tank pump maintains the level in the condensate tank and pumps the collected condensate back to the three-phase separator. The pressure in the well pad system is used to drive the sour gas through the pipeline to the end user.

Injection well system. The lithium-depleted brine from the CPF is transferred back to the well pads for reinjection to the Smackover Formation via the brine injection wells. Brine booster pumps installed at each well pad are utilized to boost the lithium-depleted brine pressure for reinjection into the injection wells.

Corrosion and scale inhibitor systems. Corrosion and scale inhibitor chemicals are stored in dedicated tanks on each pad for use in the production and disposal well systems. Dosing pumps dedicated to each well are installed to deliver the required treatment chemicals. Fresh water is used as a carrier fluid for the inhibitor chemicals being dosed to the production wells. The lithium-depleted brine in the injection system serves as the carrier fluid for inhibitor chemicals being dosed to the injection wells.

Plant design

Brine pre-treatment. The brine degassing area is designed to remove gases (primarily H₂S, methane, and CO₂) from the brine via air stripping and scrubbing. This system employs a two-stage process involving air stripping to transfer dissolved gases from the brine into an air stream, followed by a scrubbing stage to remove H₂S from the air stream. The brine from the wellfield is fed at the top of the stripping columns and flows down through the packing material; simultaneously, clean, dry air is introduced at the bottom of the tower and flows upwards, counter-current to the descending brine, causing the dissolved H₂S, methane, and CO₂ to be pulled out of the brine. The air stream exiting the top of the stripping tower is enriched with H₂S, methane, CO₂, water vapour, and other constituents of air, and continues to the scrubbing stage, which uses packed columns to bring the rich air stream into contact with a liquid absorbent that reacts with H₂S, converting it into ionic species highly soluble in the aqueous solution.

The degassed brine is pumped through a heat exchanger, transferring its heat to cooling water from the cooling tower. The cooled degassed brine is then adjusted for pH and oxidation-reduction potential using sodium hydroxide (NaOH) and hydrogen peroxide (H₂O₂) solution.

The brine filtration area is designed to protect the downstream equipment and prevent fouling of the LSS sorbent bed. Degassed and conditioned brine is pumped through multimedia filters to remove coarse suspended solids and any residual oil droplets from the brine. The filtrate is then pumped to the ultrafiltration system that uses multiple membrane cartridges mounted on skid units to remove suspended solids. The flow rate through the membranes is maintained with a programmed series of filtration, backflush and clean-in-place processes.

Direct lithium extraction (DLE). The DLE area is required to extract the lithium from the brine. The LSS DLE process developed by KTS as part of their Li-Pro™ suite of technologies (now owned by Aquatech) has been selected for the project. It is a proprietary process that utilizes a lithium chloride selective sorbent in fixed bed columns. The LSS DLE system goes through a series of loading and elution steps that are operated at specific durations and flow rates to maximize the efficiency of lithium recovery.

Pre-treated feed brine from the brine filtration process is pumped through the DLE columns, which are filled with a lithium selective adsorbent during the loading cycle. The adsorbent selectively adsorbs lithium ions from the brine along with chloride ions, leaving a lithium-depleted brine. When the adsorbent in the DLE columns is saturated with lithium and chloride ions, the loading process stops. The lithium and chloride ions adsorbed onto the adsorbent in the loading process are then eluted (released) from the adsorbent along with lesser amounts of contaminants by passing an eluent (clean water) through the DLE columns. The elution produces a lithium chloride solution (eluate) that contains over 95% of the lithium from the feed brine and up to a 99% reduction in the major contaminant ions concentrations. The eluate from the DLE columns is pumped to the eluate reverse-osmosis (ERO) stage. The lithium-depleted brine is directed to the lithium-depleted brine treatment area prior to reinjection.

Lithium chloride purification and concentration. The ERO area aims to concentrate the eluate by reverse osmosis. Eluate (raw lithium chloride solution) from the LSS DLE system is filtered and cooled before being pumped to the reverse-osmosis membranes, which operate with a feed pressure of 500 to 600 psig and provide the initial separation of water from the eluate. The eluate is concentrated through multiple stages of reverse-osmosis membranes operating up to 1,200 psig for final separation of the water and lithium chloride (along with other ions) in the eluate. The concentrated eluate (ERO concentrate) produced is expected to have a lithium concentration of over 3,000 mg/L and similarly increased concentration of contaminants. The ERO concentrate is pumped to the softening area and the ERO permeate is reused as eluent in the DLE process.

The softening area is designed to remove most of the calcium (Ca) and magnesium (Mg) ions present in the ERO concentrate. The concentrated eluate from the ERO stage is dosed with sodium hydroxide (NaOH) and soda ash (Na₂CO₃) solutions to precipitate magnesium ions as magnesium hydroxide [Mg(OH)₂] and calcium ions as calcium carbonate (CaCO₃) in stirred reactor tanks. The slurry from the reactor tanks is pumped to the clarifier. Flocculant is added to agglomerate the finer solids in the slurry to improve their settling rate. The clarifier overflow is pumped through a polishing filter to remove any remaining fine suspended solids before being sent to the ion-exchange (IX) area. The clarifier underflow is fed to the filter press where it is filtered, dewatered and washed producing a filter cake of mainly CaCO₃ and Mg(OH)₂ solids. The filtrate is pumped back to the clarifier and the solid is dissolved and transferred to the lithium-depleted brine treatment area. Any carbon dioxide evolved by mixing is sent to the CO₂ recovery system.

The ion exchange (IX) area is intended to minimize the traces of calcium (Ca), magnesium (Mg) and boron (B) remaining in the brine by employing selective ion exchange resins packed in columns. Softened lithium chloride brine from the softening area is pumped through a candle filter to the Ca/Mg IX columns. As the brine passes through the columns, it encounters selective resins, which capture calcium and magnesium ions from the brine. After the resin becomes loaded (saturated with calcium and magnesium ions), the loading step stops and the ion-exchange resin is eluted and regenerated. Brine that has been purified through the Ca/Mg IX columns is pumped to the B IX columns, where the brine is contacted with selective resins that capture boron, using the same operating principles as for the Ca/Mg IX columns. The purified brine is pumped to the OARO system.

The OARO area aims to concentrate the treated lithium chloride brine after IX by reverse osmosis. Treated lithium chloride brine from the IX process is filtered and cooled before being pumped to the OARO stages, obtaining a concentrated (high TDS) lithium chloride solution. The OARO concentrate is pumped to the mechanical evaporation area. The system uses higher permeate TDS to lower osmotic pressure difference across the membranes, enabling efficient lithium chloride brine concentration up to 186,000 mg/L at 1,100 to 1,200 psig. The permeate is reused as eluent in the DLE process. In the OARO process, energy recovery devices are used to capture and reuse the pressure energy from the concentrated stream in the reverse osmosis process, significantly reducing overall energy consumption.

The mechanical evaporation-crystallization area is designed to evaporate water from the concentrated lithium chloride brine coming from the OARO and crystallize sodium chloride out of the lithium chloride brine due to its saturation. The concentrated lithium chloride brine from the OARO system is pre-heated and fed into the evaporator brine sump where it is mixed with the recirculated concentrated brine. The recirculation pump moves the brine to a distributor plate which distributes it into the tubes, and then brine flows downwards by gravity as a thin film along the inner walls of the tubes. Heat transfer through the tube walls causes the brine to boil within the tubes and the resulting brine and vapour mixture exits the bottom of the tubes, where they separate. The concentrated brine flows to the brine pool, where it mixes with the feed and is recirculated to the top. The vapour flows through the top of the evaporator to two mechanical vapor recompression (MVR) fans, increasing its pressure, and then flows to the shell side of the evaporator heat exchanger, where it condenses. The condensate is recirculated to the process to be used as part of the eluent in the LSS DLE system. The concentrated solution obtained in the evaporator is heated up close to sodium chloride saturation temperature before entering the crystallizer vapour body where crystallization of sodium chloride occurs. As the brine slurry becomes supersaturated, salts crystallize from the solution, and crystals are continuously formed within the brine slurry in the crystallizer body before entering the recirculation pump. The formed sodium chloride slurry is sent to a centrifuge where the sodium chloride crystals are continuously removed as discarded salts. Sodium chloride crystals are discharged to the repulping tank where the salts are dissolved, obtaining a saturated sodium chloride solution that is pumped to the lithium-depleted brine treatment area. The concentrated lithium chloride brine (centrate discharging from the centrifuge) is pumped to the carbonation area.

Lithium carbonate conversion. The lithium carbonate conversion circuit will be subject to vendor information and selection in the following stage of design. The lithium carbonate conversion process described in the report is a base case design from Ausenco.

The carbonation area is required to obtain lithium carbonate from the hot concentrated lithium chloride brine (centrate). The concentrated lithium chloride brine from the evaporation-crystallization stage is filtered before passing through a set of heat exchangers to raise its temperature. Soda ash solution is filtered to avoid introducing additional solids that would precipitate in the carbonation process and potentially contaminate the product. The hot concentrated brine is mixed with the filtered soda ash solution in three stirred carbonation reactors. The slurry produced in the carbonation reactors, solid Li₂CO₃ with impurities such as magnesium carbonate and calcium carbonate, is fed to a centrifuge, obtaining strong mother liquor (centrate) and crude Li₂CO₃ (solid). The strong mother liquor is pumped to the neutralization area, with a portion recycled back to the softening area to recover lithium from this stream. The crude Li₂CO₃ discharges into the repulping tank, where it is mixed with hot demineralized water under constant agitation to promote the dilution of the cake impregnation and to achieve a near-zero contaminant contribution in the following centrifuge stage. The crude carbonate slurry is fed to a second centrifuge where the solid phase of the slurry is separated from the liquid phase, and the solid phase is washed with hot demineralized water, displacing 99% of the mother liquor that was impregnated in the solid. After separation and washing, a weak mother liquor (liquid weak centrate) and crude Li₂CO₃ are obtained from the centrifuge. Weak mother liquor is pumped to the reagent area to reduce water requirement in the soda ash solution preparation and recover the diluted lithium that was separated from the cake. The crude Li₂CO₃ solid is conveyed to the bicarbonation reactors.

The neutralization area aims to lower the pH of the strong mother liquor by dosing hydrochloric acid (HCl), making the solution suitable for recirculation to the DLE stage, where lithium is recovered as lithium chloride. The strong mother liquor from the carbonation stage is pumped into three stirred reactors in series where diluted HCl (10%) is added to decrease the pH to a level suitable for the DLE. The neutralized mother liquor obtained in the reactors is pumped to the CO₂ stripping tower, where low-pressure steam is added to strip the CO₂ produced by the neutralization reactions. From the stripping tower the neutralized mother liquor is pumped to a tank and then recirculated to the brine degassing area. The separated CO₂ from the stripping column, together with the CO₂ produced in the reactors, is sent to the CO₂ recovery system.

Li₂CO₃ purification area comprises bicarbonation, ion exchange (IX), and decarbonation stages, along with a CO₂ recovery system. In the bicarbonation stage, the insoluble crude Li₂CO₃ from the carbonation process is converted to soluble lithium bicarbonate (LiHCO₃) by reacting the Li₂CO₃ with CO₂ in pressurized reactors. The crude Li₂CO₃ obtained in the carbonation process is conveyed to the first reactor, where it is mixed with demineralized water and decarbonated mother liquor. The decarbonated mother liquor is cooled in a closed system using heat exchangers and a chiller prior to mixing. Recycled CO₂ from the CO₂ recovery system and make-up fresh CO₂ are added to the pressurized reactors, producing soluble LiHCO₃. Insoluble solids accompany the reaction product and remain in the solid phase, allowing them to be filtered out from the lithium bicarbonate (LiHCO₃) solution, which is then pumped to the bicarbonation IX stage.

The bicarbonation IX stage is intended to minimize the traces of calcium (Ca) and magnesium (Mg) remaining in the lithium bicarbonate solution by employing selective ion exchange resins packed in columns. The lithium bicarbonate (LiHCO₃) solution from the bicarbonation stage contains calcium and magnesium impurities that were present with the soda ash added in the carbonation process. The LiHCO₃ solution is filtered and then pumped to the Ca/Mg bicarbonation IX columns. As the brine passes through the columns, it encounters selective resins, which capture calcium and magnesium ions from the brine. After the resin becomes loaded (saturated with calcium and magnesium ions), and before contaminants break through into the product, the loading step stops and the ion exchange resin is eluted and regenerated. Lithium bicarbonate that has been purified through the bicarbonation Ca/Mg IX columns is pumped to the decarbonation stage.

In the decarbonation stage, the lithium bicarbonate solution is heated, promoting the precipitation of the target product battery-quality lithium carbonate. The polished LiHCO₃ solution obtained from the bicarbonation IX stage is recirculated from the decarbonation reactors through medium-pressure-steam heat exchangers, promoting the precipitation of Li₂CO₃. Condensate from the heat exchangers is collected in a tank and pumped to the LSS DLE stage. A slurry of Li₂CO₃ crystals with residual unconverted LiHCO₃ from the decarbonation reactors is fed to the thickener, obtaining a solution with lithium as overflow and a settled precipitate Li₂CO₃ as underflow. The underflow is pumped to the centrifuge where the Li₂CO₃ crystals are dewatered and washed, obtaining strong mother liquor and wet lithium carbonate (Li₂CO₃) (solid wet product). The mother liquor is mixed with the thickener overflow, and the mixture is recycled to the bicarbonation stage. The wet Li₂CO₃ is conveyed to the product handling area.

The carbon dioxide recovery system is a process package that recovers CO₂ generated during the softening, neutralization, bicarbonation, and decarbonation stages for reuse within the process. The recovered CO₂ is sent to the bicarbonation reactors in the purification area to react with the insoluble Li₂CO₃, producing soluble LiHCO₃.

The product handling area is responsible for preparing the battery-quality Li₂CO₃ from the decarbonation stage to meet the physical market specifications, moisture content and particle size distribution. This area includes the final steps of product drying and micronizing. Wet lithium carbonate cake from decarbonation stage is dried to remove moisture from the crystal solids in an indirect heated rotary dryer, heated by natural gas combustion. The dryer heats the lithium carbonate and evaporates water to reduce the moisture content to <0.2 wt%. Dry crystalline Li₂CO₃ product is sized by micronizing to achieve the defined battery quality crystal size (D50: ~5 μm and max. 40 μm) using the principle of high-velocity impact between particles. The micronized product is transferred to the packaging system.

Lithium-depleted brine treatment and reinjection

At the lithium-depleted brine treatment area, any remaining solids present in the brine are dissolved. The brine is combined with spent reagent streams from different areas of the CPF. The pH of the combined stream is adjusted to near 5.5 (range is pH 4.5 to 6.0) by adding either NaOH or HCl, as required. The lithium-depleted brine is transported by pipeline back to the wellfield for reinjection. Treated lithium-depleted brine reinjection into the Smackover Formation is feasible because the chemicals used in the unit processes and waste streams are inorganic and contain the same ions as the incoming Smackover brine.

Product handling

Pipelines will be used to transport sour gas that is stripped from the brine at the CPF to the third party oil and gas operator.

Handling of the product (battery-quality lithium carbonate) takes place in a dedicated dry area, isolated from any reagents, substances, or solutions that could cause contamination. Within this area, the product undergoes quality testing before being packaged in bulk bags and placed on pallets, ready for distribution. The palletized and wrapped bulk bags of the product are then transported by forklift and stored on multi-level racks in the product warehouse, ready for further transportation to customers.

Energy, water, and process materials requirements

Power. The power supply for the different areas of the project will be provided by an electrical system powered by a natural gas-fueled generation plant. The overall power demand of the project is 40 MW, comprising 20,382 kW for the Central Processing Facility and 19,626 kW for wellfield loads, for a total of 40,008 kW, with a generator size of 42,400 kW.

Water. At each well pad, fresh water is required to support drilling operations for both production and disposal wells, as well as to enable chemical injection for maintaining well integrity after completion. Two freshwater supply wells will be installed at each well pad to meet the anticipated water demand. Estimated freshwater consumption during drilling activities is approximately 28.4 m³/h (125,041 gpm) per well. For ongoing chemical injection during production, freshwater usage is projected at approximately 0.9 m³/h (3.96 gpm) per well.

The total projected fresh water requirement for the project, based on the process plant design, is 3,170,000 m³/a (2,570 ac-ft). Fresh water will be supplied from several submersible well pumps in wells drilled on the CPF site. Fresh water is needed to produce various types of water, including process, demineralized, cooling, seal, fire, and potable water. Treated, deionized water is essential in several unit processes, such as for the DLE elution stage, but also in preparing and diluting reagents, in the ion exchange operation, and in washing the centrifuge cakes. The process plant design incorporates water recovery and recycling, reducing the total water requirement.

Reagents. The main reagents required in the lithium carbonate production process are 32% hydrochloric acid (HCl) at 40,560 t/a, hydrogen peroxide (H₂O₂) at 1,520 t/a, 50% sodium hydroxide (NaOH) at 15,470 t/a, sodium carbonate (Na₂CO₃) at 50,380 t/a, and carbon dioxide (CO

Key reported parameters

Technical qualifications

The report describes a proposed facility and design estimates; operating performance and final configuration are not confirmed.