The quartzite on the Property is of the metamorphic type, of probable sedimentary origin, and occurs as large-amplitude folds formed in response to multiple episodes of folding. The exploration model used by Rogue for the deposits on the Property primarily relies on field mapping, the positive topography resulting from the erosion-resistant quartzite, and the lack of magnetic susceptibility of the quartzite, in contrast with the geophysical signature of the magnetic paragneiss in the footwall of the “G” unit and in the hangingwall of the “H” unit.

The Property hosts several map-scale units that correspond to high purity quartzite. However, Rogue selected two units (“G” and “H”) as the best drilling targets for further development. The “G” unit extends along a NE direction through the central point of the Property, whereas the “H” unit is about 250 m to the NW, in the northern sector of the Property. The width of the “G” quartzite unit varies along strike, but reaches a maximum of 260 m, with an average of 150 m.

The quartzite on the Property is generally coarse-grained, massive, locally fractured. It may contain traces of biotite, muscovite, hematite, magnetite, ilmenite, fuschite, rutile commonly associated with coloured quartzite. Clusters of sillimanite with pyrite were occasionally observed.

The different impurities cause the changes of colour in the quartzite. In the case of iron, fine hematite or magnetite crystals impart a pervasive pink or red colour to the quartzite, whereas iron staining (surface coating) is observed along fractures and fractured contact zones that promote water circulation.

The quartzite exhibits internal zones distinguished by their colour or by sheared zones that represent fairly continuous bands within the deposit.

SNC-Lavalin evaluated the potential for a quarry operation at Silicon Ridge to feed the direct ship feed with 180 kt per year of silica mineralization.

The mining method selected for this Project is a conventional truck and shovel, drill and blast quarry operation. Vegetation, topsoil and overburden will be stripped and stockpiled for future reclamation use. The mineralized material and waste rock will be mined with 5 m high benches, drilled, blasted and loaded into rigid frame haul trucks with hydraulic excavators.

The seasonal quarry operation is based on the contractor operating 5 days per week, 12 hours per day, and 6 months of the year during the warmer seasons. Overburden removal may take place during the winter to take advantage of the frozen ground conditions. Two of the three Resource pits were designed for the Silicon Ridge project in order to target 20 years of production at 200 kt of blasted resource per year from the South West (SW) and the North East (NE) pit. The Central North (CN) pit was not designed for the 20 year plan due to a higher overburden depth than in the NE pit, although it is still within the Resource Estimate. The quarry has a nominal capacity to extract 200 kt per year of run of mine to produce approximately 180 kt per year of lump silica.

The SW pit is approximately 635 m long and 170 m wide at surface with a maximum pit depth from surface of approximately 105 m to a bottom of 885m elevation. The total surface area of the pit is roughly 0.105 km2. The SW pit contains 3.37 Mt of run of mine feed (ROM) above the cut-off grade (CoG) with an overall strip ratio (SR) of 1.93:1 waste tonnes to feed tonnes.

The NE pit is a string of 5 phased pits including a separate small pit at the west end (phase 1) and 3 mini pits at the east end (phase 5). The central 3 phases of the NE pit combine for one large pit in the middle. These 3 central phases overlap each other, relocating the pit access and haulage ramp within the pit further to the east with each phase. The combined 5 pits are approximately 1 km in length 130 m wide at surface with a maximum pit
depth from surface of approximately 110 m. The total surface area of the pit is roughly 0.069 km2. The NE pit contains 1.24 Mt of ROM above CoG with an overall SR of 2.01:1 waste tonnes to feed tonnes.

The silica product will be ROM with crushing and directly shipped. The silica products will be crushed and screened by a contractor to minus 120 mm (top size) and 20 mm (bottom size). The 2016 PEA Study included a processing plant for separating a low grade product, which is no longer in the mine plan.

This study includes mine operations separating low grade material for stockpiling to keep marketing options open, but does not address processing of a secondary processed product. SNC-Lavalin recommends Rogue complete market analysis of potential end users as the planning process progresses in the future to determine if changes in the market warrant producing a secondary low grade product. In the event that no low grade product is added to the project, the low grade stockpile will remain as a mineralized waste dump/stockpile, designed to long term geotechnical design parameters.