Lithium Argentina AG

Sampling, Analysis and Data Verification

Millennial Lithium drainable porosity analysis (2016-2019)

Samples were obtained from ‘undisturbed’ core during the 2016-2019 Millennial Lithium drilling programs and analysed for drainable porosity by Corelabs in Houston, Texas. In addition, rotary drill cuttings were sent to GSA in Tucson, Arizona for repacking, triaxial testing, and drainable porosity analysis.

Both Corelabs and GSA offer advanced petrophysical and geological analysis and interpretation services for core samples. These laboratories operate in compliance with ISO 9001:2008 Certification ensuring that processes and procedures adhere to internationally recognized quality standards. The analytical procedures for determining drainable porosity for each laboratory are further described below.

Corelabs drainable porosity analysis are based on centrifuge methodology and involve the following:

38 mm (1.5-inch) diameter cylindrical plugs were cut from the sample material.

Samples were frozen with dry ice to maintain their integrity, if required.

Sample weight and thickness were measured.

The plugs were encapsulated in Teflon and nickel foil as required, and nickel screens were placed on the ends of the plugs. The encapsulated samples were then weighed.

Bulk density was calculated as: (Mass of plug before encapsulation) / (Calliper bulk volume).

The plugs were placed in brine and saturated under vacuum to ensure full saturation. Corelabs utilized a standard sodium chloride brine with a NaCl concentration of 244,000 ppm with a density of 1.184 gm/cm3.

The weight of the saturated cores was recorded.

The samples were desaturated in a high-speed centrifuge for 4 hours. Spin rates were calculated to provide a drainage pressure of 1 pound per square inch (psi) for poorly cemented or loose sands and 5 psi for clay and halite.

The drainage was collected, and the volume was recorded. The effluent was saved for possible analysis. However, it should be noted that the fluid collected from these cores may not be representative of in situ brines if re-saturation with NaCl was required.

Plugs were removed from the centrifuge and weight was recorded. Drained fluid volume was calculated as: (saturated plug weight - drained plug weight) /1.184. Drainable porosity was calculated as (Drained fluid volume) / (Calliper bulk volume).

Total porosity was calculated after drying the samples for 5 days at 115.6 degrees Celsius to record dry weight.

All weight loss is assumed to be water lost from pore space where volume of water loss is calculated as: ((Drained plug weight) – (Oven-dried plug weight))/ (Water density of 1 g/cc).

Total porosity is calculated as ((Drained fluid volume) + (Oven drying fluid loss))/ (Calliper bulk volume).

GSA drainable porosity analysis procedures for repacked sediment samples include the following steps:

All loose and sandy samples were packed into test cells with moderate effort without prior knowledge of bulk density or other consolidation tests. Additional repacking was performed on some samples with minimum and maximum effort to evaluate the effectiveness and variation of hand-packing at higher and lower densities. Bulk densities approximately 0.1 g/cm3 lower and higher than the initial density were achieved, respectively.

The sandy material was packed into a stainless-steel ring in several small lifts. The weight and packing height of the first lift were used to guide the subsequent lifts to ensure consistent density packing. Scales were used to track the equipment, cell, and sample weights throughout the process, and the final packed and assembled core weight was recorded.

Plastic air tubing, approximately 6 inches in length, was inserted into the top of each core to monitor saturation and prevent brine solution spillage. The cores were then assembled and saturated slowly from the bottom up using provided brine. A combination of gravity feed and vacuum suction was used to achieve the target saturation. If the target saturation could not be reached using gravity feed alone, vacuum suction was applied. The saturation process lasted for up to 24 hours. Once fully saturated, the cores were closed at the bottom with a hose clamp to prevent brine solution loss and disconnected from the saturation setup.

Each cell assembly underwent three pressure steps after being transferred to a test rack. The first step, at 0 mbar pressure, lasted for 24 hours and was applied to remove excess saturation solution. To approximate the release of brine solution at 120 mbar and 1/3 bar of the brine solution, two sequential pressure steps were used at 120 mbar and 1/3 bar, respectively. The 120-mbar pressure step was maintained for 2 days, and the 1/3 bar was continued for another 2 to 4 days. Weight measurements were taken twice a day to determine the loss of brine solution over time. After the final step the cores were disassembled and samples were oven dried to determine total porosity following the procedure described in MOSA, 2002, Part 4 Ch. 2, 2.3.2.1.

To estimate the brine solution release volumes at the 120 millibar and 1/3 bar pressure steps, the difference was calculated between the measured total porosity and the moisture retained after the pressure plate measurements as outlined in MOSA (2002), Part 4, Chapter 3, Section 3.3.3.5. The solution’s release volume obtained at 1/3 bar was regarded as an approximation of the maximum solution drainage that could occur under gravity or pumping conditions, and hence was used to determine the specific yield.

After completing the tests, the estimated particle density and weight data from core samples at various pressure steps were entered into a spreadsheet. The spreadsheet was programmed to automatically calculate the salt weight left in the sample after drying, estimated porosity, and water content change. Furthermore, particle density was optimized during data processing by utilizing all prior test measurements and using a solver in Microsoft Excel. The laboratory report presented the calculated particle density for each sample.

Arena drainable porosity samples (2021-2022)

36 samples from the Arena 2021-2022 drilling program were sent to GSA for drainable porosity analysis. All samples were tested using the ‘Rapid Brine Release’ method to measure Sy and Pt. Brine release drainable porosity was measured at 120 mbar and 333 mbar of pressure, where:

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Brine release at 120 mbar represents drainable porosity from sand dominated sediments and rapid brine release from macropores.

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Brine release at 333 mbar represents the Sy for intermediate to finer texture sediments.

Brine release values at 120 mbar were provided for reference and 333 mbar values were presented as the estimated Sy (drainable porosity). A subset of paired samples representative of the range in lithology types were selected by AW and GSA for testing using the Relative Brine Release Capacity method by DBSA in Albuquerque, NM. The goals of the test work were to provide Sy and Pt values for each sample, summary statistics of Sy and Pt by lithological group, and to compare the Sy and Pt values derived for paired core samples using the RBR and RBRC methods.

The table immediately below lists the physical properties analyses carried out by GSA. In addition to the RBR testing, physical property tests were run by GSA to assist in lithologic characterization and interpretation of results including bulk density testing (ASTM D2937-17e2) on all RBR samples.