The Clearwater Project in Central Alberta, Canada, is designed to produce battery-grade lithium hydroxide monohydrate from Leduc Formation brine using a combination of direct lithium extraction and refining processes with a planned initial production rate of 32,250 tonnes per year.
The Clearwater Project, situated in the Bashaw District of Central Alberta, Canada, represents a proposed brine-based lithium production operation. The project is a Pre-Feasibility Study detailed in a 2024 NI 43-101 Technical Report. The core of the operation is the Central Processing Facility, which is planned to process 232,500 m³/d of brine to produce battery-grade lithium hydroxide monohydrate. The expected combined lithium recovery performance from the direct lithium extraction technology, lithium refining, and conversion steps is 90.4%. Applying an assumed Central Processing Facility availability of 92%, the initial facility production rate is calculated to be 32,250 t/a. A key design criterion is that under normal operations, the Central Processing Facility will not be reliant on fresh water to meet its process water demands, as all process demands for pure water will be met by recycling reverse osmosis and evaporator distillates.
The process flowsheet begins with brine degassing and proceeds through lithium recovery, lithium chloride purification and concentration, and finally conversion to lithium hydroxide monohydrate through crystallization, drying, and packaging. The direct lithium extraction process is designed to produce no waste streams and requires no chemical treatment. The lithium-depleted brine, which will be a combination of the brine pumped to the Central Processing Facility and lithium-rich recycled streams, is estimated to remain a Class 2 fluid as defined by the Alberta Energy Regulator and can be readily reinjected back into the Leduc Aquifer. The final product specifications include a maximum calcium content of less than 0.002 wt%, potassium of less than 0.003 wt%, and sodium of less than 0.003 wt%.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Brine flowrate | 232,500 | m³/d | Feed to Central Processing Facility |
| Combined lithium recovery | 90.4 | % | From direct lithium extraction, refining, and conversion |
| Central Processing Facility availability | 92 | % | Assumed |
| Initial production rate | 32,250 | t/a | Lithium hydroxide monohydrate |
| DLE eluate Li concentration | 600–1,000 | mg/L | Approximately 93% recovery with minimal contaminants |
| Polished LiCl Li concentration | 6,000–8,000 | mg/L | After purification and concentration |
| DLE sorbent capacity | 1.0–1.5 | g Li/L sorbent | For adsorption and desorption |
| Extraction efficiency | 92 | % Li | For direct lithium extraction |
| Carbonation conversion | 88 | % | Lithium conversion from LiCl to Li₂CO₃ |
| Membrane process recovery | 96 | % | Forecast lithium recovery |
| Final product calcium | <0.002 | wt % | Specification |
| Final product potassium | <0.003 | wt % | Specification |
| Final product sodium | <0.003 | wt % | Specification |
Overview
The Clearwater Project is planned to produce battery-grade lithium hydroxide monohydrate from Leduc Formation brine. The processing facility will receive brine at a flowrate of 232,500 m³/d. The process involves direct lithium extraction using an aluminate based sorbent in a continuous separation process, followed by purification and concentration steps. The lithium chloride solution is then converted to lithium hydroxide monohydrate via carbonation and crystallization processes. The final product will be packaged under a carbon dioxide-free environment to maintain quality. The design emphasizes water recycling, and under normal operations, the facility will not rely on fresh water for process demands.
Key Process Stages
The initial stage of the process involves brine degassing treatment. Brine will arrive at a separator vessel at a pressure of approximately 800 kPa before being depressurized and flashed between 300 and 400 kPa in a two-phase separator. The remaining gas flashed off in these tanks will be captured in a vapour recovery unit. The acid gas from the vapour recovery unit will be compressed and water condensed out. The degassed brine is then fed to the direct lithium extraction process.
Direct lithium extraction uses an aluminate based sorbent in a continuous separation process with groups of 30 columns operating in a carousel configuration. The carousel service operates in four modes: adsorption, desorption, and other stages. During adsorption, lithium containing brine is pumped through the sorbent beds, loading the sorbent with lithium and chloride ions. The desorption process uses hot water to desorb lithium and chloride ions from the sorbent, producing an eluate stream with approximately 600–1,000 mg/L of Li at approximately 93% recovery with minimal contaminants. The DLE process is designed to produce no waste streams and require no chemical treatment.
The LiCl eluate stream from the DLE process moves through purification and concentration processes. The first step is chelating ion exchange to remove divalent ions such as calcium and magnesium, followed by boron ion exchange, which will be operated in a continuous separation process with teams of 12 resin columns. The purified LiCl eluate, now free of calcium and magnesium, reports to a mechanical vapor recompression unit for concentration. After purification, the polished LiCl solution will have a lithium concentration of 6,000–8,000 mg/L, with calcium and magnesium reduced from 350 mg/L and 40 mg/L to less than 2.0 mg/L respectively, and boron reduced from 250 mg/L to 5.0 mg/L.
In the carbonation stage, the purified and concentrated LiCl eluate reacts to convert 88% of the lithium from LiCl to Li₂CO₃. The resulting slurry is transferred to a centrifuge to produce a product. The ion exchange process targets the removal of multivalent impurity metal ions and is completed in three fixed-bed columns operating in a lead-lag-regeneration arrangement. This is followed by lithium chloride conversion to lithium hydroxide where the lithium carbonate is converted to lithium hydroxide monohydrate.
Crystallization is achieved through a two-stage process. The first stage uses a forced circulation crystallization unit to crystallize crude lithium hydroxide monohydrate. The underflow from this unit enters a washing thickener where it is washed in counter-current flow against a portion of fresh mother liquor. The hydrocyclone overflow is collected and filtered in a candle filter to avoid transfer of fines into the crystallization process. The second stage uses a pure LiOH crystallization unit with a falling film evaporator and mechanical vapor recompression turbofans. The undersaturated feed solution from the pure LiOH crystallization unit is heated, and the condensate surplus is reused in the DLE process for desorption.
The final stage involves solid-liquid separation, drying, and packaging. The product exits the drier and is transferred to one of two product storage silos through a closed-loop system. Oversized material is returned to the upstream process. The final centrifuge produces battery-grade product. Screening takes place before the product enters the silos, and a carbon dioxide-free environment is maintained during product transfer, storage, and packaging. Cool, dry gas lowers the product temperature to meet the design requirement.
Additional Interesting Data and Summary
The Clearwater Project is designed with a strong emphasis on environmental sustainability, particularly regarding water usage. Under normal operations, the Central Processing Facility will not be reliant on fresh water, as all process demands are met by recycling reverse osmosis and evaporator distillates. The process design also specifies that the DLE process produces no waste streams. The equipment list includes four two-phase separators, four gas compressors, three vapour recovery units for brine degassing, 14 reinjection pumps, and a range of downstream processing equipment including ion exchange vessels, crystallizers, a drying system, and a packaging system.
The lithium-depleted brine reinjection is a key design feature, ensuring that the spent brine is reinjected into the Leduc Aquifer, maintaining a closed-loop system. The process also includes a mother liquor recovery unit to maximize lithium recovery and minimize losses. The final product storage silos and packaging systems are designed to maintain product quality through a carbon dioxide-free environment.
Key Processes
- Direct lithium extraction with aluminate based sorbent in carousel configuration, achieving 92% extraction efficiency and 93% recovery in eluate
- Chelating ion exchange for removal of calcium and magnesium to less than 2.0 mg/L
- Boron ion exchange in continuous separation process with 12-resin-column teams
- Mechanical vapor recompression for water removal and concentration
- Carbonation converting 88% of lithium to Li₂CO₃
- Two-stage crystallization producing crude and purified lithium hydroxide monohydrate
- Hydrocyclone and pressure filtration for solid-liquid separation
- Candle filter for fines removal prior to crystallization
- Falling film evaporator with mechanical vapor recompression turbofans
- Drying, screening, and packaging under carbon dioxide-free environment
Source: Clearwater Project , 2024 NI 43-101 Technical Report, 2024.
Project website: Clearwater Project, 2024 NI 43-101 Technical Report
