Uranium-vanadium mineralisation in the Laguna Salada Project has the principal characteristics of surficial uranium deposits according to the classification of Toens et al., 1984.

Two principal styles of uranium-vanadium mineralisation have been identified at Laguna Salada as follows:

- Of principal economic interest is a tabular, gently undulating layer that contains yellow-green uranium-vanadium minerals at shallow depth within unconsolidated, sandy gravel. This style of mineralisation occurs in the Guanaco and Lago Seco areas in gravel-dominated clastic facies of different ages – Pleistocene at Guanaco and Holocene at Lago Seco. Powdery and finely crystalline uranium-vanadium minerals occur between the grains in the sandy matrix of the gravel and also as partial coatings on sand grains and clasts. Studies indicate that approximately 10% of the contained uranium occurs as rinds on clasts. Carnotite (K2(UO2)2(VO4)2.3H2O) is the dominant uranium-vanadium mineral and has a variable habit from slightly cohesive to compact masses of crystals.

- The second style of mineralisation is found in the Buried Lake area where carnotite straddles the unconformity between the gravel sequence and the underlying, organic-rich mudstones. Mineralisation within this layer occurs in interstices in the sandy matrix and on pebbles in the gravel as well as within cracks and associated with organic material in the underlying mudstone. The true potential of this style of mineralisation at Laguna Salada is undefined at this time.

Guanaco Area
Uranium-vanadium mineralisation in the Guanaco area is closely associated with carbonate distribution in the gravel layers of the sedimentary sequence of the Pampa de Arroqui Formation. Mineralisation is generally evident as a yellow-green staining on the sides of trench walls and the generally tabular mineralised zone is marked by abruptly gradational, slightly undulating boundaries that cross-cut contacts between conglomerate and sand layers.

The generally sub-horizontal layer of mineralisation at Guanaco extends from beneath the patchy soil cover to a maximum depth of 3m to 4m. The mineralised area that has grades above 50ppm U3O8 ranges from 0.2m to 2m thick with an average of 0.94m in the Guanaco area. Mineralisation at Guanaco is made up of a number of mineralised sheets, each of which is several square kilometres in extent in which mineralisation shows remarkable continuity. Each mineralised sheet is separated from the next by a gap of lower-grade mineralisation that may be up to 200m wide.

Lago Seco Area
Uranium mineralisation in the Lago Seco sector covers an area of more than 25km² and lies within 1m of
surface beneath poorly developed, partial soil cover. The average thickness of the mineralised interval in
trenches with grades above 50ppm U3O8 is 0.85m with a range between 0.3m and 1.9m. Mineralisation forms a sub-horizontal layer that is associated with carbonate and gypsum that has formed partially cemented nodules in the gravel and sand facies of the Gran Laguna Salada Formation. The majority of the uranium mineralisation is located in the matrix of the gravel with a lesser component encrusting clasts.

Continuous surface mining
The mining operation contemplates the use of two Wirtgen SM 2200 (400tph capacity) continuous surface miners. This model of surface miner has a cutting width of 2.2m and a variable cutting depth to a maximum of 30cm.

The mining operation is contemplated to follow the procedure outlined below:

- Removal of the overlying soil by grader with FELs filling truck- trailers that would transport the soil for immediate spreading by bulldozer and grader over backfill at the trailing edge of the mining strip, or for temporary stockpiling adjacent to the trailing edge;

- Barren overburden gravel cut by the surface miner would be fed up a conveyor belt system and either discharged directly back into the strip in the trench from which mineralised gravel had previously been completely removed, or into 50t truck- trailers for backfill at the trailing edge of the mining excavation. Any excess backfill would be temporarily stored in piles adjacent to the trailing edge of the excavation;

- Once the overburden had been removed, excavation of the exposed mineralised layer would commence with the surface miner making multiple passes along the trench, the number of passes being dictated by the thickness of the mineralised unit and the constraint of the 30cm maximum cutting depth. 50t truck-trailer units loaded by the continuous miner would transport the mineralised material to the semi-mobile scrub- screen trains for beneficiation; and

- Mineralised material would be discharged from the truck- trailers directly into the primary hopper at the beneficiation unit or stockpiled on a patio adjacent to the hopper. Oversized gravel from the beneficiation units would be trucked to the trailing edge of the mining strip where reclamation would be ongoing.

Conventional Mining
Areas of irregular topography on the margins of the gravel mesas would be mined with shovels or bulldozers, with the gravel being lifted into truck-trailer units with FELs. There is typically no soil cover in these areas of irregular topography, and hence there is no necessity for stripping this component of the overburden prior to mining. Barren gravel overburden would be stockpiled adjacent to the excavation while the mineralised layer is removed and beneficiated.

Carnotite, the principal uranium-vanadium mineral at Laguna Salada, occurs as a powdery filling between the sand grains and as a partial rim on pebbles in the gravel. To upgrade the feed to the plant, the carnotite-bearing material would be separated from the gangue material in semi-mobile beneficiation units comprising of scrubbing and screening stages.

In the scrubbing stage, ROM material is slurried in saline water and passed through rotating scrubber units. Discharge from the scrubber units will pass through trommel screens to remove coarser +3mm particles, after which the -3mm material will pass through a number of classification steps to ultimately isolate only the <75µm fraction for further treatment in the Hydromet Plant. From the beneficiation plants, the upgraded and significantly reduced tonnage of fine uranium-bearing material is received in the Hydromet Plant concentrate thickener feed tank as slurry in saline water.

The Hydromet Pla?nt is designed to leach and recover uranium and vanadium to produce separate, high grade uranium and vanadium products. The presence of gypsum (calcium sulphate) in the alkaline leach circuit would lead to excessive reagent consumption and gypsum is therefore rejected prior to reaching the leach circuit.

Residual gypsum in the upgraded fine uranium-bearing material is leached with saline groundwater from the property, resulting in a leach solution containing high levels of calcium sulphate.

Two different technologies are considered for removal of calcium sulphate from the leach solution, so that the saline solution can be re-used in the beneficiation plant. Both technologies will be tested and evaluated on actual gypsum leach solution to determine the most cost effective option. Once test work has been completed, a final selection will be made in the next stage of the project development. The two technologies are:

- Membrane technology, implementing nanofiltration to retain calcium sulphate to a low volume, high concentration waste stream to remove calcium sulphate from solution; and

- Ettringite precipitation using milk of lime, aluminium hydroxide and caustic soda to remove calcium sulphate from solution.

Extraction of uranium and vanadium is in an alkaline leach at a temperature of 80°C. After solid-liquid separation of the leach discharge slurry, the PLS is treated in a two-pass membrane plant. Pass one produces a low volume, high uranium tenor solution from which an intermediate uranium-vanadium product is precipitated. The second pass recovers leach reagents from solution for reuse, and a water stream is used as filter wash solution.

The refining circuit is designed to re-dissolve the intermediate uranium-vanadium product and separate the uranium and vanadium. Calcining of the uranium precipitate produces yellow cake as a high-grade uranium oxide, and calcining of the vanadium precipitate produces high-grade vanadium pentoxide.