The Project is underlain primarily by a generally north trending sequence of Permian to Mississippian sedimentary rocks composed of siltstones, mudstones, sandstones, conglomerates and limestones, subdivided into several units or formations.

A dolomite hydrothermal alteration overprint has been interpreted within the Project area, based on geochemical drill hole data from drill holes that variably penetrate into the grey–brown siltstone and black mudstone sequences, and vanadium-rich zones.

Vanadium mineralization is stratigraphically controlled, and appears to follow the strike and dip of the host lithology, near the contact between an overlying grey–brown siltstone and the underlying brown to black mudstone unit of the Devonian-age Woodruff Formation. The mineralized zones form as stratigraphic subunits or beds within the Woodruff Formation mudstone, hosting elevated concentrations of vanadium in the form of vanadium pentoxide (V2O5).

The most persistent, thickest, and highest-grade vanadium unit lies in the brown–black mudstone unit and averages approximately 115 ft (35 m) thick, striking north–south over 6,000 ft (1,800 m) of length and 2,000 ft (600 m) wide in the east–west direction.

The mineralization is locally exposed at surface at both the Central and South Zones, but mostly at a shallow depth less than 200 feet (60 m) from surface. Above and below the high-grade zone are other vanadium zones within the brown–black mudstone unit that are generally less persistent laterally, which are of moderate grade (0.2–0.5% V2O5) but are thinner (30–75 ft thick).

There is a relatively persistent, flat-lying, high-grade vanadium-enriched bed averaging 115 ft thick within the upper grey–brown mudstone unit to the west of the Central Zone. Other vanadium zones within the grey–brown mudstone are generally less persistent laterally, of moderate grade (0.2–0.4% V2O5), and are thinner (30–60 ft thick).

Mineralogical studies by First Vanadium and UCC show the vanadium is present in the form of metahewettite (CaV6O16•3(H2O) and corvusite ((Na,Ca,K)V8O20•4(H2O), which are finely and evenly disseminated throughout the host lithologies with grain size from a few micrometers to almost 100 µm, averaging about 10–20 µm.

Other vanadium minerals identified in the deposit in rare, very rare or trace amounts were montroseite ((V3+,Fe3+)O(OH))–goethite, pascoite (Ca3(V10O28)•17H2O), steigerite (Al(VO4)•3H2O), tangeite (CaCu(VO4)(OH)), tyuyamunite (Ca(UO2)2(VO4)2•5–8H2O) and vesignieite (BaCu3(VO4)2(OH)2).

The Carlin Vanadium deposit is interpreted to be a syngenetic-type vanadium deposit. The vanadium is believed to have originally formed in a deep, restricted marine basin associated with the depositional environment of the western assemblage lithologies. As the marine basin filled, sub- basins formed. Organisms likely in the form of algae, bloomed on the shallow flanks of the sub- basins. As these organisms died, they contributed to carbon input into the basin. It is interpreted that the vanadium was concentrated into laterally relatively continuous mudstone/siltstone units by precipitation, absorption aided by carbon accumulation and evaporation processes as the restricted basin filled, evaporated, and concentrated the seawater into salts.

The mineral deposits along the Carlin Trend form a suite of deposits known as Carlintype, or sediment-hosted, low-grade disseminated gold deposits. The Carlin Trend hosts the largest concentration of gold deposits in North America. The preferential host rocks are autochthonous carbonate assemblage rocks that are now preserved in uplifted tectonic windows. Within specific deposits, Cretaceous and Tertiary dike swarms and a Jurassic-aged granodiorite stock (Goldstrike stock) may constitute as much as 15% of the mineralized material. Host rocks are most commonly thinly-bedded silty or argillaceous carbonaceous limestone or dolomite, commonly with carbonaceous shale/mudstone. Although less mineralized, non-carbonate siliciclastic and rare metavolcanic rocks can locally host gold that reaches economic grades. Felsic plutons and dikes may also be mineralized at some deposits. Deposits typically have a tabular shape, are stratigraphically and structurally controlled, are localized at contacts between contrasting lithologies or structural intersections, but can also be discordant or breccia-related.

Mineralization consists primarily of micrometer-sized gold and sulphide grains disseminated in zones of siliciclastic and decarbonated calcareous rocks and are commonly associated jasperoids. Major ore minerals include native gold, pyrite, arsenopyrite, stibnite, realgar, orpiment, cinnabar, fluorite, barite, and rare thallium minerals. Gangue minerals typically comprise fine-grained quartz, barite, clay minerals, carbonaceous matter, and late-stage calcite veins.

The 2020 PEA assumes conventional open pit mining using a conventional Owneroperated equipment fleet. The mining operations will have an 11-year life, with one year of pre-production. A stockpiling strategy is planned, which will provide process plant feed after the cessation of mining operations.

The Project is designed as a conventional truck-shovel operation with 45 st trucks and 6.5 yd3 front-end loaders (FEL). The pit design includes four nested phases to balance stripping requirements while satisfying the process plant requirements.

The design parameters include a ramp width of 82 ft, road grades of 10%, bench height of 20 ft, targeted mining width of 200 ft, berm interval of 40 ft, fixed slope angle of 40° and a minimum mining width of 82 ft.

The smoothed final pit design contains approximately 16.4 Mst of mineralized material and 52.7 Mst of waste for a resulting stripping ratio of 3.2:1. Within the 16.4 Mst of mineralized material the average grades are 0.71% V2O5.

The deposit is proposed to be mined in four nested phases, including the ultimate pit limit. The schedule was developed in yearly periods. The operating phases were sequenced starting in the south portion of the deposit, then proceeding to mine the north and central portions, to finally mine to the final pit limit. The scheduling constraints set the maximum mining capacity at 7 Mst/a, and the maximum number of benches mined per year at 10 in each phase.

To maximize Project value, an elevated cut-off strategy was followed to feed the highest possible grades at the beginning of the operation. A total stockpiling capacity of 6.1 Mst is required to store medium- and low-grade material.

The production schedule based on the Indicated and Inferred Mineral Resource captured by the final pit design supports a 17 year mine life, including one year of preproduction. The amount of re handled mill feed material from stockpiles is 6.1 Mst. The average grades to the process plant over the life-of-mine (LOM) are forecast to be 0.71% V2O5.

Stockpile and Crushing
The higher-grade mill feed material will be processed during the initial years of the Project, while the lower-grade mineralization will be stockpiled close to the processing plant. The oxide and non-oxide mill feed material will be stockpiled separately. The final five years of operation will be fed exclusively from these lower-grade stockpiles.

Mill feed material will be either dumped directly into the plant feed hopper or withdrawn from the stockpile via a front-end loader to feed a primary jaw crusher. The jaw crusher discharge will be screened and the oversize will be fed to a secondary cone crusher in closed circuit with the sizing screen. The screen undersize will advance to the milling section.

Milling and Classification
The oxide mineralization is friable, and testing has shown that the material breaks down to a slurry in an attrition scrubber. The fine vanadium minerals are liberated from the coarser gangue mineral which provides the opportunity to upgrade the vanadium minerals using particle size classification. Processing the mill feed material through a ball mill is potentially detrimental to recovery by particle size, due to overgrinding of the gangue minerals, so the oxide mineralization will bypass the primary ball mill and report directly to the secondary tower mill, which will be configured to do duty as an attrition scrubber.

The non-oxide mineralization is substantially more competent than the oxide mineralization. The crushed mineralization will feed into a ball mill in closed circuit with a hydrocyclone cluster, classifying the overflow to a P80 of 105 µm. The overflow will advance to a tower mill which will be configured as a secondary milling stage.

The tower mill will operate in closed circuit with a hydrocyclone cluster, classifying the overflow to a P80 -50 µm. The overflow will advance to a fines classification circuit. Limited comminution testwork is available at this time. A Bond mill work index of 13.7 kWh/t was used to size the comminution equipment.

For the purposes of the process plant design, the mudstone-hosted mineralization types are classified as being an oxide and a non-oxide type. The mineralization types have significantly different mineralogical and physical characteristics which results in differences to the front end of the flowsheet for the two mineralization types:
- The oxide mineralization is friable, with the gangue being dominated by acidconsuming dolomite and K-feldspar, and is not significantly upgradable by conventional flotation or gravimetric methods
- The non-oxide mineralization is competent, is also dominated by acid-consuming dolomite and K- feldspar, but generally contains a greater proportion of sulphide minerals. In addition, the non- oxide mineralization contains a high proportion of sulphur-bearing kerogen with which the vanadium is associated.

Testing showed that it is possible to upgrade the mineralization by cycloning:
- The cyclone underflow from the oxide mineralizati ........