The Bonnie Claire lithium deposit appears to be a lacustrine salt deposit hosted in sediments. The Project area as a sedimentary basin, from an environment and geology point of view, is reasonably well represented by the USGS preliminary deposit model, which describes the most readily ascertainable attributes of such deposits as light-colored, ash-rich, lacustrine rocks containing swelling clays, occurring within hydrologically closed basins with some abundance of proximal silicic volcanic rocks. The geometry of the Bonnie Claire Deposit is roughly tabular, with the lithium concentrated in gently dipping, locally undulating Quaternary sedimentary strata. The sedimentary units consist of interbedded calcareous, ashrich mudstones and claystones, and tuffaceous mudstone/siltstone and occasional poorly cemented sandstone and siltstone.

From a lithium deposit point of view, Bonnie Claire is interpreted to be a new type of sediment- hosted lithium deposit whereby lithium compounds such as lithium carbonate and lithium salts have been deposited within the fine grain clay, silt, and sand pore space. Although most of the sediment-hosted lithium in the literature occurs in clays, it does not at Bonnie Claire.

Bonnie Claire is the lowest in elevation of a series of intermediate-size playa-covered floodplains, with an area of about 85 km2 that receives surface drainage from an area of more than 1,200 km2. The plain and alluvial fans around it are fault-bounded on all sides, delineated by the Coba Mountain and Obsidian Butte to the east, Stonewall Mountain to the north, the Bullfrog Mountains and Sawtooth Mountains to the south, Grapevine to the southwest, and Mount Dunfee to the northwest.

The area surrounding the Project area is dominated by uplifted basement rocks that were mostly built from silicic ash-flow tuff. The four reverse circulation (RC) borings drilled on the Project, with a maximum depth of 603.5 meters (1,980 feet) (BC-1602), did not encounter the bottom of the sediments.

Lithium mineralization comes from the evaporation of surface and groundwater. As a highly-soluble salt, lithium mobility and deposition are driven by the movement of surface and groundwater rich in lithium into a closed basin and by the concentration of salts resulting from evaporation.

Significant lithium concentrations were encountered in the alluvial fans and playa within the Project area. Elevated lithium was encountered at ground surface and to depths of up to 603.5 meters (the deepest depth of RC-drilling so far). The lithium in the sediments at the Project occurs as lithium carbonate or lithium salts deposited in the fine grain clay, silt, and sand pore space. The lithium is not found within the clay crystal lattices as is common with most sediment hosted deposits. The overall mineralized sedimentary package is laterally and vertically extensive, containing roughly tabular zones of fine-grained sediments grading down to claystone.

The average grade of lithium appears to depend on the sedimentary layers:
• Sand or sandstone appears to have the lowest grade, averaging about 30 ppm Li near the surface to 570 ppm Li at depth;
• Silt or siltstone appears to have approximately 135 ppm Li near to the surface to 1,270 ppm Li at depth;
• Clay, claystone, and mudstone appear to have 300 ppm Li near the surface to 2,550 ppm Li at depth.

It also appears that fine-grained materials trap and contain lithium and therefore form the highest-grade portions of the deposit.

The Quaternary sedimentary deposits are of primary interest to this study. They consist of clastic materials ranging in size from large boulders on the alluvial fans to fine-grained clay in the playa. The deposits are fluvial, lacustrine, or aeolian, depending on the location and the energy of the deposition environment. The fluvial deposits were deposited in alluvial fans, along stream channels, and in flood plains. Finegrained lacustrine deposits were deposited in the bottom of ephemeral lakes. Aeolian deposits exist throughout the Project area.

The fluvial quaternary sedimentary deposits have been subdivided into Older Alluvium and Younger Alluvium. Older Alluvium has been deformed and dissected in places, and parts of it are cemented into a firm fanglomerate. Younger Alluvium consists mostly of unconsolidated gravel, sand, silt, and clay which form recent fluvial and lacustrine deposits.

The quaternary sediments have created a flat landscape over most of the Project area. The alluvial fans located in the eastern portions of the Project area are commonly mantled with weathered remnants of rock washed down from the surrounding highlands. Alluvial fans are also covered with sporadic shrubs, which are the only vegetation in the region. The playas are completely covered by mud and salt and are commonly referred to as mud flats in this report.

Drilling logs show that within the Project area, the extensional sedimentary basin has been filled by sand, silt, and clay. From the available drilling, it appears the material grades from clay to sand in particle size and minor amounts of cementation. However, all sediments appear to contain between 5% and 10% clay.

The QP evaluated both open pit mining and borehole mining (BHM) and a combination of both for the Bonnie Claire Lithium Project. Both are potentially viable options; however, the prevalence of relatively lower grade material near surface results in high stripping ratios early in the mine life for open pit mining. The use of BHM eliminates this by targeting high-grade mineralization at depth as well as offering other Project benefits, including reduced surface disturbance (i.e., no open-pit) and reduced tailings at surface due to tailings backfilling underground. The soft nature of clay should make it ideally suited to water jet cutting. For these reasons, the QP selected BHM as the more viable method at this stage of the Project. Test work and test borehole mining are required to support this mining method. If future drilling and assaying programs identify higher grade, shallow mineralization, the mining method could change.

As outlined above, The QP has used a base case of borehole mining (BHM) using jetting and pumping for this study. The borehole recovery using jetted drilling and pumping would pump high-pressure water through drill holes into the formation while simultaneously pumping the resulting loosened material out, creating a void that could be backfilled with suitable material to prevent caving from the surface. One benefit of this method would be that it could be targeted to deeper higher-grade locations without the need for removal of the shallow lower-grade material.

Borehole mining, also known as slurry mining, is a process in which a tool incorporating a water jet cutting system and downhole slurry pumping system would be used to mine minerals through a borehole drilled from the ground surface to the buried mineralized material. Water jets from the boring tool erode the mineralized material to form a slurry, which would flow into the inlet of a slurry pump at the base of the tool. The slurry would then be pumped to the surface for transfer to the processing plant by pipeline. (Savanick, 1993).

The systems for transportation and fragmentation of ore are incorporated into a single machine that would be operated remotely from the surface by a two- or three-person crew. Disturbance to the environment would be minimal and short-term; no overburden would be removed, and subsidence would be avoided by backfilling. (Savanick, 1993)

The BHM method is based on in-situ water jet cutting of mineralized material, creating a slurry and delivering it to the surface. The borehole mining tool would be lowered into the borehole, and high pressure water would be pumped down. At the bottom of the tool, one portion of that water would be ejected through a nozzle as a water jet that would cut the mineralized material, creating a slurry. The remainder of high pressure water would travel to the eductor, which would produce a vacuum, sucking the slurry up the borehole to the surface. The slurry would be pumped to the processing plant for separation, drying, and processing or a solids separation step could be performed at the borehole location. Clarified water would be returned to the borehole and pumped down again, creating a recirculating BHM water supply system. (Abramov, 2001).

The process has been developed based on pretreatment developed by the US Bureau of Mines followed by downstream industry-standard commercially proven unit operations. The designed throughput for the process is 15,000 tonnes per day or 5,175,000 tonnes per year. The anticipated lithium recovery is 75%.
At this stage, benchtop laboratory test work has been conducted across the entire flowsheet with preliminary testing of final product production. This flowsheet represents a typical lithium production pathway producing high grade (>99.5%) lithium carbonate. The process has been divided into basic unit operations including:
• Feed Preparation;
• Pretreatment;
• Lithium Extraction;
• Secondary Impurity Removal;
• Solution Polishing;
• Lithium Carbonate Production;
• Tailings;
• Utilities – Water, reagents, natural gas, and electricity.

The feed preparation circuit is designed into three main components: screening, drying, and calcina ........