Two styles of mineralization have been observed at the Project: contact nickel-PGE mineralization and reef PGE mineralization. The presence of several highly-anomalous assays from rocks lying within higher portions of the River Valley Intrusion’s stratigraphy suggests that there are opportunities for PGE mineralization such as reef or stratabound-type targets, or narrow, high-grade breccia zones.

The three largest and most economically interesting mineralized bodies of the East Bull Lake Suite Intrusives are the East Bull Lake and Agnew Lake Intrusions (situated within the Sudbury Province), and the River Valley Intrusion (situated in the Grenville Front Tectonic Zone). The River Valley Intrusion, the largest of the East Bull Lake Intrusive Suite by area, covers an area of approximately 200 km2. An economically important feature commonly shared by the Agnew Lake, East Bull Lake, and River Valley Intrusions is the occurrence of a copper-nickel-PGE bearing breccia unit situated at the base of the intrusions, where the footwall contact is preserved.

The contact between the River Valley Intrusion and the Archean basement trends southeasterly for a distance of approximately 16 km. On the basis of surface mapping and diamond drilling, the idealized sectional stratigraphy of the mineralized environment comprises five major units, from the layered rocks of the River Valley Intrusion in the west to the igneous basal contact of the intrusion to the east.

The mineralized breccia unit occurring at the contact has been identified along most of the 16 km strike length. The contact is divided into several areas based on structural offsetting, alteration grades, and grade distribution. The zones of mineralized breccia starting in the northwest and proceeding to the southeastern extent of the contact on the Property are: Dana North, Dana South, Banshee, Lismer’s Extension, Lismer’s Ridge, Varley, Azen, Razor, and River Valley Extension.

Dana North / Pine
Dana North, the most northwestern zone, has a strike length of approximately 1,000 m. The zone dips steeply to the west-southwest at 80 to 85°. The rocks have undergone lower- to middle-greenschist facies metamorphism. This area exhibits little structural disturbance. The Pine Zone is a mineralized splay off of Dana North. It is unknown at this time if the Pine Zone is structurally emplaced or primary magmatic placement. The strike is roughly perpendicular to Dana North and dips to the southeast at approximately 40° to 45°. The average thickness of the Zone is 45 m, yet thins to 15 m in the east.

Dana South
Proceeding southeast, Dana South is approximately 500 m in length, dips at 80 to 85° to the west-southwest, and varies greatly in width between holes and sections. The rocks here have undergone mid- to upper-greenschist metamorphism and the southern extent of this zone exhibits structural disturbance due to the proximity of the Dana Lake Shear Zone.

Banshee
The next zone further to the southeast is Banshee Lake which is a fault-offset band of marginal series rocks. This block of breccia has been displaced approximately 350 m to the southwest. The metamorphic grade of the rock here is lower amphibolite facies. The strike length of this zone is approximately 500 m and dips to the southwest at 60 to 70°. The rocks here show relatively more structural fabric in the way of fracture, shears, and foliation than at Dana.

Lismer Ridge and Lismer Extension
The next two zones, which can be described together due to the proximity and identical geology, are Lismer Extension and Lismer Ridge. These zones have a combined strike length of approximately 2,400 m dip east-southeast at about 60 to 70°. These zones have a lower- to midamphibolite grade metamorphic over print and exhibit a more penetrate structural fabric in the way of foliation throughout than the last zones. The rocks are more highly chloritized and carry more biotite relative to the other zones. The sulphides are composed of a higher percentage of chalcopyrite and are recrystallized along foliation planes.

Varley
The next zone is Varley, which has strike length of approximately 2,500 m and dips to the west at approximately 60 to 70°. The rocks here have undergone lower- to mid-amphibolite grade metamorphism but display little structural deformation.

Azen
At this juncture the contact swings to the east from the previous northwest-southeast orientation and is where the Azen Zone is encountered. This zone has a strike length of approximately 1,300 m and dips 30 to 50° south. The rocks have a mid- amphibolite facies over print.

Razor
Razor has a strike length of approximately 1,400 m. This zone dips progressively steeper to the east from about 80° to the south to steeply north at the far eastern end. The rocks have undergone upper amphibolite grade metamorphism.

River Valley Extension
The River Valley Extension has a strike length of approximately 2,400 m. The zone consists of two parallel mineralized horizons that are truncated to the north by a strike-slip fault. To the north of the fault, a single mineralized horizon exists. This zone dips steeply at about 80° to the southwest or northeast depending on the location.

The River Valley Deposit is relatively shallow and lends itself to conventional open pit mining methods. Accordingly, the PEA mine plan entails developing 14 open pits aligned across approximately 16 km on the Property. An open pit mining and processing schedule has been developed for the Project. The mine production plan utilizes Measured, Indicated and Inferred Mineral Resources. Inferred Mineral Resources are considered too speculative geologically to have the economic considerations applied to them to be categorized as Mineral Reserves, and there is no certainty that the Inferred Mineral Resources will be upgraded to a higher Mineral Resource classification.

Open pit optimizations were run based on an NSR cut-off value of $11.45/t and a pit slope angle of 48°, with a mining cost for all materials of $2.00/t. A slope angle of 50° for PEA level pit optimization was recommended by Mine Design Engineering Inc. (“MDEng”), and it was subsequently flattened by 2° in the pit optimizations to allow for haulage ramps. Benches and haul roads were added during the creation of each pit design.

Mining dilution of 9.5% and 3% mining losses at diluting grades that averaged 0.22 g/t PdEq were incorporated to estimate the diluted potentially mineable portion of the Updated Mineral Resource Estimate (process plant feed). Total process plant feed was estimated at 78.1 Mt at a LOM average grade of 0.88 g/t PdEq. Total waste material within the open pits was estimated at 278 Mt, giving a LOM strip ratio of 3.6:1. A production schedule was generated at 6.0 Mtpy process plant feed. The open pit production schedule consists of one year of pre-production for pre-stripping followed by 13 years of mining and a partial final year of stockpile reclaim. The target peak annual mining rate is 40 Mt tonnes of material per year, or 110,000 tpd.

It is assumed that the open pits will be operated as a contract mining operation using conventional open pit mining diesel equipment consisting of 254 mm rotary drills, 29 m3 hydraulic excavators, 221 t off-highway haul trucks and auxiliary equipment. The open pit operation will require the development of several waste rock storage facilities (“WRF”) located immediately adjacent to the mining areas. A management and supervision team of NAM employees will direct the mining contractor. The River Valley mining operation will require a steady-state open pit workforce of approximately 189 personnel.

The process plant is designed to produce a single saleable PGE concentrate.

The run-of-mine (“ROM”) mineralized material from the mine is crushed in a single primary crushing stage prior to the milling circuit. The primary crushing stage consists of a primary jaw crusher driven by a 400 kW (536 hp) motor. The discharge is conveyed to a live stockpile, which provides an operating buffer between the crushing and grinding circuits.

The grinding circuit consists of a SAG mill in closed circuit with a pebble crusher and two ball mills in parallel. The SAG mill has a diameter of 9.7 m and a length of 4.3 m and is driven by a 7,460 kW (10,000 hp) motor. The SAG mill output is directed to a vibrating screen where oversized material is directed to the pebble crusher. The pebble crusher is essentially a cone crusher of dimensions 2.3 x 2.4 x 0.6 m (90 x 93 x 23 in) and is driven by a 315 kW (422 hp) motor. The pebble crusher product is returned to the SAG mill. The undersize material from the vibrating screen is discharged to a pump box which splits the stream to feed between two ball mills in parallel.

Each ball mill has a diameter of 6.7 m and length of 9.1 m and is driven by a 7,460 kW (10,000 hp) motor and it is in closed circuit with a hydrocyclone cluster to produce an overflow with a P80 of 75 µm.

Hydrocyclone underflow material is returned to the ball mills, while the overflow reports to a flotation conditioning tank that feeds the flotation circuit.

The flotation circuit feed is conditioned with CMC depressant, SIBX, AERO 3477, MIBC and Na2SiO3. The conditioned slurry is directed to the rougher feed box and into the first of four rougher flotation tank cells with 200 m3 of volume each. Rougher tailings are sent to the tailings thickener, while the rougher concentrate is pumped to the first cleaner stage.

The first stage of cleaning consists of four conventional forced air flotation cells with 15 m3 of volume each. Tails from the 1st cleaner cells are pumped to the 1st cleaner scavenger feed box and then to three conventional forced air 1st cleaner scavenger flotation cells, each with 15 m3 of volume. Tails from the 1st cleaner scavenger cells are directed to the tailings thickener. Concentrate from the 1st cleaners is pumped to the 2nd cleaners, while concentrate from the 1st cleaner scavengers is returned to the 1st cleaner feed box.

The 2nd cleaner bank consists of eight conventional forced air flotation cells, each with 1.4 m3 of volume. The concentrate from this stage is pumped to a regrinding vertically stirred media mill (vertimill) before feeding the 3rd cleaner stage. A grind size P80 of 20 µm is targeted. The 2nd cleaner tails are directed to the 1st cleaner feed box.

The 3rd cleaner bank consists of three conventional forced air flotation cells, each with 0.3 m3 of volume. The 3rd cleaner concentrate reports to the concentrate thickener, while the 3rd cleaner tailings report to the 1st cleaner feed box.

The final concentrate, as it comes out of the concentrate thickener is filtered using a single plate and frame filter press prior to shipment.

The underflow from the tailings thickener is pumped to the tailings pond while the overflow is directed to the process water tank. Water recovered from the concentrate thickener and filtering is also directed to the process water tank. The water from the process water tank is distributed to all the areas of the processing plant.