This report details the proposed processing route for producing battery-grade lithium carbonate from brine extracted from Minera Salar Blanco's mineral properties in the Salar de Maricunga area.
Report context
The Technical Report NI 43-101 Definitive Feasibility Study Stage One, Minera Salar Blanco, Atacama Region, Chile, describes the design for facilities to produce an average of 15,200 TPY of battery-grade lithium carbonate over a 20-year mine life. The report presents a proposed processing scheme based on pilot evaporation tests and design work, distinguishing between evaporation pond operations, the Salt Removal Plant (Phase 1), and the Lithium Carbonate Plant (Phase 2).
Processing route
Evaporation pond operation
Raw brine extracted from the salar is fed to solar evaporation ponds where various salts precipitate, including halite, sylvinite, and carnallite. The ponds are simple structures of very large size and shallow depth, covered by a geomembrane to guarantee impermeability. Fresh brine from production wells, which has a lower temperature, is first fed to the production plant to act as cooling brine. The outlet cooling brine, at a higher temperature, is then sent to the first evaporation pond. Ponds operate in sequence, with interconnected channels using gravitational energy where possible, and pumping where topography does not allow gravity flow.
Pilot evaporation tests indicated that the high concentration of calcium, magnesium, and lithium in the concentrated brine lowers brine activity significantly, and the eutectic end point of about 3-4% wt lithium is never reached at ambient concentrations. Concentrating to higher levels of about 1.5% wt in summertime showed significant lithium losses as lithium borates and through entrapment in crystallized salt in the ponds. Based on this testwork, the process was designed for a concentration target of about 0.9% wt, which was proved can be reached and maintained consistently.
Approximately 5,400,000 tons of brine are treated annually in the evaporation ponds. Concentrated brine from the final evaporation pond is pumped to reservoir ponds that act as storage and buffer for seasonal variations. Annual salt generation from the evaporation ponds includes halite (978,406 TPY, with 10% entrained brine), sylvinite (81,697 TPY), carnallite (151,756 TPY), and calcium chloride from reservoir ponds (160,757 TPY).
Salt Removal Plant – Phase 1
Concentrated brine from the reservoir ponds feeds the Salt Removal Plant, where calcium and magnesium are removed as tachyhydrite and calcium chloride salts, and boron is removed using solvent extraction. The process begins with an evaporation stage that allows tachyhydrite salt formation, separated using solid-liquid separation equipment. Brine then enters a first stage of crystallizers for further tachyhydrite formation and separation, followed by a second crystallizer stage where calcium chlorides are formed and removed.
Brine is then fed to a boric acid crystallizer. The addition of hydrochloric acid is considered to generate boric acid precipitation, with sodium sulphite added if needed to reduce bromine formation and avoid corrosion damage. The lithium-concentrated brine then feeds a solvent extraction stage where boron is removed using a selective extractant and diluent mixture. Boron extraction stages are carried out at acidic pH, with stripping stages at basic pH producing a boron-rich solution for discard. Boron-free brine enters a third and final crystallizer stage to remove remaining calcium as calcium chloride salts.
The resulting lithium-concentrated brine, with low calcium and magnesium content, is stored in intermediate tanks to feed the Lithium Carbonate Plant. Annual discard salts from Phase 1 include tachyhydrite plus calcium chloride (304,491 TPY, with 13% moisture) and boric acid cake (10,915 TPY, with 50% moisture).
Lithium Carbonate Plant – Phase 2
The Lithium Carbonate Plant receives concentrated brine from the Salt Removal Plant. The first stage involves calcium and magnesium reduction using recirculation of mother liquor, milk of lime, and a soda ash solution mixed in reactors with concentrated brine at 60°C. This promotes precipitation of calcium carbonate and magnesium hydroxide, which are separated using solid-liquid separation equipment.
For final contaminant removal, an ion exchange stage uses specific resins in columns to remove remaining impurities, generating contaminant-free brine. The cleaned brine then enters the carbonation stage, where it contacts a soda ash solution. Formation of lithium carbonate using soda ash is described as optimum at temperatures close to 80°C, allowing lithium carbonate precipitation in a solid state.
The pulp from carbonation undergoes solid-liquid separation with washing. Dewatered lithium carbonate is transported to a dryer, then packed into separate maxi bags and stored in a final product warehouse. Annual discard salts from Phase 2 include calcium chloride and magnesium hydroxide (16,150 TPY, with 51% moisture).
Reagents and water purification
Annual reagent consumption designed for the process includes lime (1,411 TPY solid), soda ash (35,320 TPY solid), caustic soda (2,826 TPY as 20% solution), hydrochloric acid (14,342 TPY as 32% solution), sodium sulphite (137 TPY solid), flocculant (18 TPY), solvent extraction diluent (50 TPY), and solvent extraction extractant (22.5 TPY). Soda ash is prepared as a 28% concentrated solution using recycled water mixed with solids in a tank containing excess soda ash to assure saturation. Lime is slaked with water to generate calcium hydroxide for magnesium hydroxide precipitation.
Process water is treated in a treatment plant using mainly reverse osmosis to generate required water quality and avoid contaminant entry.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Lithium carbonate production capacity | 15,200 TPY average | Design |
| Mine life | 20 years | Design |
| Brine treated in evaporation ponds | 5,400,000 tons annually | Design |
| Evaporation pond lithium concentration target | ~0.9% wt | Design (based on pilot testwork) |
| Salt Removal Plant (Phase 1) discard salts | 304,491 TPY tachyhydrite + CaCl2; 10,915 TPY boric acid cake | Design |
| Lithium Carbonate Plant (Phase 2) discard salts | 16,150 TPY CaCl2 + Mg(OH)2 | Design |
| Soda ash consumption | 35,320 TPY | Design |
| Lime consumption | 1,411 TPY | Design |
| Hydrochloric acid consumption | 14,342 TPY (32%) | Design |
| Solvent extraction extractant consumption | 22.5 TPY | Design |
| Solvent extraction diluent consumption | 50 TPY | Design |
Project website: https://www.dhigroup.com/projects/feasibility-studies-for-a-lithium-brine-mining-project-in-northern-chile
Technical qualifications
The report states that the design was based on pilot evaporation tests that indicated limitations in reaching higher lithium concentrations. The report notes that concentrating to about 1.5% wt in summertime showed significant lithium losses as lithium borates and through entrapment in crystallized salt. The design target of about 0.9% wt is described as proved to be reachable and maintainable for consistent and continuous feed. The report includes references to figures (Figure 17-1, 17-2, 17-3, 17-4, 17-5, 17-6, 17-7, 17-8) and tables (Table 17-1, 17-2, 17-3, 17-4) that are presented in the original document but whose content is not fully reproducible in text form. The salt generation figures include assumed entrained brine percentages and moisture contents as stated in the tables.
Source: Technical Report NI 43-101 Definitive Feasibility Study Stage One, Minera Salar Blanco, Atacama Region, Chile, Section 17 Recovery Methods.
Consolidated report summaries
The following former standalone pages about this operation were consolidated here on October 25, 2026. They are retained for source traceability; dates and figures reflect each report’s own effective date and may be superseded by the current information above.
Feasibility Study of Blanco Project
This Definitive Feasibility Study presents the technical basis for a proposed 20,000-tonne-per-year lithium carbonate operation at the Blanco Project in the Atacama Region of Chile.
Report context
The technical report N° 209020-00049-0000-GE-TEN-0001, effective 17 January 2019, was prepared by WorleyParsons and FloSolutions for Minera Salar Blanco S.A. as a National Instrument 43-101 compliant Definitive Feasibility Study of the Blanco Project. The Blanco Project is located in Salar de Maricunga, approximately 170 km northeast of Copiapó, Chile, at an elevation of 3,750 masl. The property covers approximately 2,563 ha of mineralized ground in Salar de Maricunga, with an additional 100 ha northeast of the salar and 1,800 ha approximately 8 km north of the salar for evaporation ponds and process facilities. Air temperature averages 5 to 6 °C annually, precipitation averages 150 mm per year, and potential evaporation ranges between 2,100 mm and 2,400 mm per year.
Processing route
Background and historical testwork
Lithium recovery process development for the Blanco Project is based on testwork conducted between 2011 and 2018. Initial evaporation tests were carried out in 2011 by the University of Antofagasta as part of the Li3/MLE exploration program. Additional process testwork was conducted by POSCO in 2012/13. Further evaporation pond tests were performed in 2016 and 2018, and salt removal and lithium carbonate tests were conducted in 2017 and 2018.
Proposed design – solar evaporation ponds
The proposed recovery method, as described in the study, uses solar evaporation ponds as the primary concentration step. Brine extracted from the wellfield is pumped to evaporation ponds where water is removed by natural evaporation, concentrating lithium and other dissolved salts. The operation of the solar evaporation ponds involves sequential evaporation stages that precipitate salts in a controlled manner. The annual generation of salts from the evaporation ponds is reported in the study.
Proposed design – salt removal plant
Following solar evaporation, the concentrated brine is processed in a salt removal plant. A simplified process diagram for the salt removal plant is presented in the study. The salt removal plant removes precipitated salts prior to lithium carbonate production.
Proposed design – lithium carbonate plant
The concentrated and purified brine is then processed in a lithium carbonate plant. Simplified process diagrams for the lithium carbonate plant, presented as two sheets in the study, describe the processing steps. Reagents used for the process are documented in the study. The plant also includes water purification and equipment cleaning systems. Solid waste management for the lithium carbonate plant is addressed in the study.
General process configuration
A general process diagram and a process block diagram are provided in the study, illustrating the overall processing route from brine extraction through evaporation, salt removal, and lithium carbonate production.
Key reported parameters
| Parameter | Value | Unit | Basis |
|---|---|---|---|
| Design lithium carbonate production rate | 20,000 | TPY | Definitive Feasibility Study design |
| Lithium process recovery efficiency (assumed) | 58 | % | Reserve estimate assumption |
| Average lithium concentration in brine | 0.14 | % weight | Resource estimate |
| Average potassium concentration in brine | Reported | g/l | Resource estimate |
| Average annual pan evaporation | 2,100 to 2,400 | mm | Site climate data |
| Average annual precipitation | 150 | mm | Site climate data |
| Average annual temperature | 5 to 6 | °C | Site climate data |
| Evaporation test initial brine composition (Li) | 0.14 | % weight | 2011 University of Antofagasta testwork |
| Evaporation test initial brine composition (K) | 0.56 | % weight | 2011 University of Antofagasta testwork |
| Brine Mining Reserve (pumping to ponds) | Reported | , | Reserve estimate |
| Brine Production Reserve (Li₂CO₃ production) | Reported | , | Reserve estimate, assuming 58% recovery |
Project website: https://miningdataonline.com/property/3215/Maricunga-(Blanco)-Project.aspx
Technical qualifications
This report was prepared to provide an NI 43-101 compliant Definitive Feasibility Study. Items related to geology, hydrogeology, mineral resources and reserves were prepared by FloSolutions. Peter Ehren was responsible for preparing all technical items related to brine chemistry and mineral processing. Capital and operating expenditures were estimated by WorleyParsons, relying on quotations requested from equipment, chemicals and other suppliers, as well as from its project database. WorleyParsons relied extensively on Minera Salar Blanco and its consultants for information on future prices of lithium carbonate, legislation and tax in Chile, as well as for general project data and information. The study includes technical judgment of appropriate additional technical parameters to accommodate certain specific characteristics of minerals hosted in liquid brine as outlined in CIM Best Practice Guidelines for Resource and Reserve Estimation for Lithium Brines.
Source: Technical Report N° 209020-00049-0000-GE-TEN-0001, Definitive Feasibility Study of MSB Blanco Lithium Carbonate Project, Atacama Region, Chile, effective 17 January 2019. Relevant sections: 1 (Summary), 13 (Mineral Processing and Metallurgical Testing), 17 (Recovery Methods).
