The Driftwood Creek and Brisco magnesite occurrences are classified as Sparry Magnesite deposits (E09) by the B.C. Ministry of Energy and Mines (Simandl and Hancock, 1998). This deposit type is characterized by stratabound and typically stratiform, lens-shaped zones of coarse-grained magnesite mainly occurring in carbonates but also observed in sandstones or other clastic sediments. Magnesite exhibits characteristic sparry texture.

Reports by Morris (1978), Rodgers (1989), and Simandl and Hancock (1992) provide the best available geologic information on the Driftwood Creek magnesite deposit. Klewchuk (2002) provides additional detail for the Eastern Magnesite area.

According to Simandl and Hancock (1992), magnesite and sparry carbonate form stratabound lenses and pockets within the “white marker beds” subdivision of the “middle dolomite” unit of the upper Mount Nelson Formation at the Driftwood Creek property. This middle unit is called unit Hmn1, with the lower part, Hmn1A, describing the buff to light grey dolomite horizon. The upper part, Hmn1B, is applied to the magnesite.

The magnesite is either white, pale grey, or beige, and weathers buff. The unit is characterized by coarse to sparry crystals, and locally contains light green interbeds less than 1 cm in thickness. The interbeds are either regular or disrupted by growth of sparry magnesite crystals within the coarsest magnesite-rich zones (Simandl and Hancock, 1992). Vestiges of hemispherical stromatolites are observed locally in finer-grained magnesite-bearing rocks. Chert, quartz veinlets, and dolomite are the most common impurities especially within the lower part of the deposit. Calcite, pyrite, and talc are typically present in trace amounts. The abundance and proportion of impurities change irregularly, both along strike and across bedding (Simandl and Hancock, 1992).

Magnesite weathers prominently, and the Driftwood Creek deposit is well exposed as an isolated ridge within relatively low valley bottom topography, at an elevation of 1,250 m (Klewchuk, 2010). Numerous cliff exposures are present, with some cliff walls greater than 15 m (50 ft) high.

Magnesite has been mapped over a strike length of 1,900 m and maximum width of about 220 m (Klewchuk, 2010). The magnesite occurs at surface in two discrete bodies; a larger “West Zone” and the smaller “East Zone”.

Texture of the magnesite is variable, ranging from fine- and medium-grained to very coarse-grained. Most of the deposit is of medium- and fine-grained texture, with irregular patches of more coarsegrained texture. Areas of coarse-grained magnesite appear to be irregularly developed within the area of exposed magnesite, and are not obviously related to any structure.

Thin quartz veins are irregularly distributed through the magnesite, in a near-ubiquitous manner, although the concentration of quartz veins does vary. There are areas with no apparent quartz, but these are not extensively developed. The more prominent quartz veins and quartz vein swarms tend to be oriented from N15°E to N60°E. Similar quartz veins are present in the host dolomite (seen mainly to the south of the Eastern Magnesite), indicating that these quartz veins are not related to development of the magnesite. It is possible that they are related to intrusives noted during drilling. These intrusives may have also introduced a second population of Fe2O3 that may be considered a potential impurity in the recovery of magnesite.

All the magnesite deposits in the Brisco and Driftwood Creek area are located within the upper half of the Mount Nelson Formation. Most are lenticular and seem to form chains, as illustrated by the Driftwood Creek deposits. All deposits are stratigraphically associated with red to purple dolomites, cherty dolomites, stromatolitic dolomites, dissolution breccias, and other rocks containing dolomite pseudomorphs after halite and lenticular gypsum crystals. Locally, stromatolitic textures are preserved, even within magnesite- bearing rocks. According to Simandl and Hancock (1992), most of the above features are indicative of the evaporitic depositional environment.

The Project will be mined by conventional, quarry pit, truck-and- excavator operation. Pit optimization and mine planning were carried out on the basis of supporting a plant capacity of approximately 1,200 tonnes per day (t/d), using Measured, Indicated and Inferred resources provided by Tuun. The Project will have an operating life of 19 years, with one year of mine rock pre-stripping followed by 18-years of production operations.

All mining equipment will be supplied and operations performed by contractors. Total material movement peaks at approximately 2.2 million tonnes per annum (Mt/a), which requires a modest production fleet of up to six conventional 40-tonne haul trucks and two-2.4 m3 excavators. Drilling can be completed with two crawler- mounted Ranger drills capable of drilling up to 127 mm diameter holes, in combination with packaged emulsion for blasting.

All resource material to the plant will be mined and hauled downhill in 40-tonne mine haul trucks to the ready pile located at the bottom of the hillside as discussed in Section 18. The resource material will then be loaded onto 40-tonne highway trucks and transported to the plant facility in Cranbrook, BC.

Mineralized material will be mined on site and then transported 210 km via truck to the plant located in Cranbrook, BC. Here the mineralized material will undergo crushing, grinding, flotation upgrading, calcination, and sintering to produce a saleable DBM product. The plant will also have the ability to produce CCM as a separate product.

Plant throughput is designed at 1,200 t/d. The plant is expected to achieve an average recovery of 90% with a magnesium oxide (MgO) purity of 94.6%. The DBM product will be bagged and transported to market for sale as a powder.

Magnesite material with a top size of 308 mm will be transported from the mine site to the processing facility via over-the-road haul trucks. The magnesite material will be stockpiled at the plant site, where it will be reclaimed and fed into the primary crusher feed bin via a front-end- loader (FEL).

A two-stage crushing operation has been designed, where the primary crushing stage will receive the material from the mine for a first pass sizing and screening. Primary crushing will be performed by a jaw crusher fed at a nominal rate of 91.3 dry metric tonne per hour (dmt/h). Crushed magnesite will be discharged to the crushing screen, where undersize material will be conveyed to the fine mineral storage bin, and oversize conveyed to secondary crushing.

The secondary crushing operation will consist of a cone crusher with a nominal feed rate of 80.2 t/h. Discharge from the secondary crusher will be conveyed to the crushing screen for particle size separation. Again, oversize material will be routed to the secondary crusher, and sized material will be transferred to the fine mineral storage bin.

The fine mineral bin will store one day’s worth (24 hours) of crushed magnesite to allow for continuous feed to the grinding plant. The fine mineral bin will feed a 2.8 m by 5.3 m ball mill at a nominal rate of 50.7 t/h. Ball discharge will be pumped to a cyclone, where a P80 split of 149- µm slurry will go to the overflow, with the underflow returned to the ball mill for additional grinding. It is assumed that the grinding circuit has a 275% recirculating rate. The ball mill cyclone will be fed a slurry of 50% solids, and will split an underflow of 65% solids and an overflow of 31% solids. Cyclone overflow will be transferred into the upgrading flotation circuit.

The ground magnesite material will initially be preconditioned in the rougher flotation conditioning tank with reagents DF250 and potassium amyl xanthate (PAX). The conditioned slurry will be pumped into the two rougher flotation cells for removal of any sulphides present in the ground magnesite slurry. The floated gangue sulphide material will be discharged to the tailings thickener, while the sulphide-free magnesite slurry will be transferred to the silicate flotation pre-conditioning thickener. Flocculant will be added to the magnesite slurry to aid in dewatering. The 31% solids slurry will be partially dewatered in the thickener, producing a 50% solids slurry in the underflow. Water in the overflow will be collected and pumped to the process water tank for reuse in upstream operations.

The thickened slurry will be pumped from the thickener underflow into a conditioning tank where Armac 1225 will be added at 250 g/t to aid in silicate removal. The slurry will be fed to a series of five conventional flotation cells where Armac 1225 will be stage added to assist in floating the silicate minerals from the magnesite stream. The floated silicate slurry will be discharged into the tailings thickener. The upgraded magnesite slurry will be collected in the magnesite filter feed tank.

Magnesite slurry from the silicate flotation circuit will be pumped through a plate-and-frame pressure filter to further dewater the 62% solids slurry to a filter cake that will be approximately 75% solids. Filtrate from the filter will be collected in the process water tank for reuse in the plant.

The magnesite filter cake will be fed to a multiple hearth furnace where excess moisture will be driven off and the magnesite partially calcined to produce a CCM powder product. The multiple hearth furnace will be operated at temperatures ranging from 760°C to 900°C to decompose the magnesite into MgO and CO2.

The CCM powder will be fed to a briquetting machine where the powder will be pressed to form cylindrical briquettes. These briquettes will either be fed to the vertical shaft kiln for further processing into DBM or bagged and sold as CCM briquette products. The CCM briquettes will be transferred to a vertical shaft furnace where they will be sintered into DBM product at temperatures ranging from 1,900°C to 2,200°C producing a product of 94.6% magnesium oxide (MgO) purity. The DBM briquettes will then be fed to a dry grinding mill and air classification to generate a final DBM powder product.