The Schaft Creek deposit has been described by many workers as a calc-alkaline Cu-Mo-Au porphyry deposit (Fox et al., 1995; Spilsbury, 1995; Scott et al., 2009; Morrison and Karrei, 2012). Other workers have considered it a shear-hosted, low-sulphidation Cu-Mo-Au-Ag vein deposit (Le Boutillier, 2013). Early mapping assigned the intrusive host rocks of the Schaft Creek deposit to the Early Jurassic (e.g., Logan and Drobe, 1993), but subsequent geochronology work constrained the age of the host rocks to the Late Triassic (Logan et al., 2000; Scott et al., 2009; unpublished U-Pb dating by Richard Friedman, University of British Columbia; unpublished U-Pb dating by Jim Crowley, Boise State University). Interpretation of the deposit is complicated by a lack of outcrop, complex hydrothermal alteration, post-mineral faults, and sparsity of drilling near the fringes of the hydrothermal system.

The deposit has historically been subdivided into two or three distinct mineralized zones, although the boundaries of this subdivision have changed during the history of the Project. These three mineralized zones are named the Liard, Paramount, and West Breccia Zones. Historically, the West Breccia and Liard Zones have been grouped by some workers into a larger domain called the Main Zone. Other workers have grouped the Paramount and West Breccia Zones into a single domain called the Breccia Zone.

Liard Zone
The Liard Zone comprises narrow, porphyritic quartz monzonite to quartz monzodiorite dikes that have been emplaced into andesitic volcanic and volcaniclastic host rocks. The dikes are typically 5 m to 50 m thick, strike north-northwest to north-northeast, and dip steeply to the east. Numerous narrow dikes occur within the eastern part of the Liard Zone, and in this area it can be difficult to trace individual dikes with confidence between drill holes or outcrops. In contrast, a single, thicker “Central Porphyry” dike occurs within the central portion of the Liard Zone.

The porphyritic dikes in the Liard Zone are spatially associated with potassic alteration, increased density of quartz-sulphide veins and vein stockworks, and a zone of elevated Cu-Au grade. The most intense alteration and highest copper grades commonly occur in the host rock immediate adjacent to the porphyry dikes, rather than within the dikes themselves. In some areas, chalcopyrite, bornite, and pyrite all occur disseminated within the host rocks and porphyry dikes, suggesting multiple mineralization episodes that have juxtaposed bornite and pyrite into the same area. Several types of vein-hosted mineralization are recognized in the Liard Zone. These include (1) Cu-Au-Mo mineralization resulting from quartz-biotite-bornite-chalcopyrite ± hematite veins with associated K-feldspar ± green mica selvages; (2) overprinting Cu-Au mineralization resulting from quartz-chlorite-pyrite-chalcopyrite ± calcite ± epidote ± hematite with associated sericite and chloriteepidote selvages; and (3) late, Mo mineralization resulting from veins of massive to semi-massive molybdenite with no apparent selvage. No preferred structural trend has been identified for this vein-hosted mineralization in the Liard Zone.

Paramount Zone
The Paramount Zone comprises an elongate, multiphase igneous-hydrothermal breccia body that has been emplaced into quartz monzonite and andesitic volcanic host rocks. The breccia body strikes north-northwest, dips steeply east, is 100 m to 300 m thick, has a strike length of approximately 1,200 m, and extends at least 600 m below surface. High-grade mineralization occurs within the breccia body and also extends 100 m to 200 m into the quartz monzonite hanging wall and, to a lesser extent, into the footwall andesitic volcanic rocks. Mineralization outside of the breccia body is associated with stockwork zones containing quartz-sulphide veins.

Three styles of mineralization occur within the Paramount breccia body, each of which is associated with different breccia cement minerals. These mineralization styles include (1) Cu-Mo mineralization associated with K-feldspar-biotite-quartz-chalcopyrite-molybdenite ± bornite veins and breccias with associated potassic alteration (Unit cHBX2), (2) Cu-Au-Mo mineralization associated with anhydrite-bornite-chalcopyrite ± molybdenite veins with associated albitic alteration (Unit cHBX5), and (3) Cu-Au-Mo mineralization associated with tourmaline-quartz-carbonate-chalcopyrite ± bornite ± molybdenite veins and breccias with associated silicic alteration (Unit cHBX3). All three of these breccia styles include sulphide cement, and the assay grade of sample intervals typically correlate with the amount of sulphide cement present (typically 0.5% to 3%). Locally, there appears to be an association between high-grade mineralization and a dark-colored intrusive breccia phase. The mineralogy of this intrusive breccia appears similar to the syn-mineral sPOR dikes in the Liard Zone, but work is required to confirm the link between these two rock types.

A mineral zonation pattern is apparent around the main breccia body in the Paramount Zone. Potassic alteration intensity, vein density, and vein thickness all increase towards the breccia zone. A clear sulphide zonation (from chalcopyrite > pyrite, to chalcopyrite > bornite, to bornite > chalcopyrite) is apparent outside of the breccia body and extends inwards. No pyrite was observed in bornite-bearing areas, which is in contrast to late pyrite that overprints areas of the Liard Zone.

West Breccia Zone
The West Breccia Zone comprises an elongated, hydrothermal breccia body that has been emplaced into andesitic volcanic and volcaniclastic rocks. The breccia body strikes north-northwest, dips steeply east, is 80 m to 160 m thick, has a strike length of approximately 500 m, and extends at least 200 m below surface. Mineralization is limited to the breccia body and seldom extends far into the adjacent footwall or hanging wall. There are a few narrow monzodiorite dikes in the vicinity of the breccia that appear similar to the monzodiorite dikes seen in the Liard Zone.

The West Breccia Zone is similar to the Paramount Zone breccia and comprises different styles of mineralization associated with certain breccia cement minerals. However, the West Breccia Zone is dominated by low- to medium-temperature breccia mineralogy and lacks the higher temperature assemblages that are observed within the Paramount Zone. The three prominent styles of breccia mineralogy at the West Breccia Zone include (1) Cu-Mo-Au mineralization associated with tourmalinecarbonate-chalcopyrite-pyrite ± molybdenite veins and breccias with associated silicic alteration (Unit cHBX3), (2) Cu-Mo mineralization associated with chlorite-calcite-pyrite veins and breccias with associated propylitic alteration (Unit cHBX4), and (3) high-grade Cu-Mo-Au mineralization associated with chlorite-actinolite-calcite-tourmaline breccia cement (cHBX7). Interestingly, although the West Breccia Zone lacks bornite, assay grades in this area are sometimes very high because of the abundance of sulphide cement (typically 2% to 10%).

Other Mineralized Zones Outside of the Deposit Area
Mineralization along the trend consists of pyrite, chalcopyrite, and occasionally bornite that occur variably as fracture-controlled, shear zone-controlled, or sparsely disseminated. Sulphide mineralization occurs in an area that is typically 100 m wide along the intrusive contact, but locally expands into wider zones that are 200 m to 500 m wide. This sulphide mineralization appears to be continuous along the margin of the batholith, from Grizzly Canyon in the north to Wolverine Creek in the south. Alteration along the trend consists predominantly of chlorite-epidote alteration of the volcanic host rocks and pink-colored or buff-grey-colored alteration of the intrusive rocks. There is potential to discover additional zones of porphyry mineralization along this trend.

The mine plan is based on a conventional open pit truck-and-shovel operation. The primary loading units will be the electric rope shovels with 45 m3 buckets. Hauling will be performed using 360 t haul trucks. A stockpiling strategy has been completed to allow the mine to give priority to higher-value material for processing and to ensure that the required mill feed is maintained. A variable cut-off grade was applied on a year-by-year basis, based on the available mineralized material for the period.

Waste rock from the pit will be stored in the east and west rock storage facilities (RSFs). The total capacity for rock storage is 571.1 million m3. Some of the mined-out waste rock from the pit will be used for embankment construction.

Over the 21-year life of mine (LOM), the open pit will be producing 1.03 billion tonnes (Bt) of waste rock and 1.03 Bt of mill feed with average grades of 0.26% Cu, 0.16 g/t Au, 0.017% Mo, and 1.23 g/t Ag. The overall LOM strip ratio is approximately 1.

Crushing
The mill feed will be transported from the proposed open pit mine site to the primary gyratory crushers by haul trucks. A total of two crushing facilities (one stationary and one semi-mobile) are proposed to crush the mill feed at an average rate of 7,389 t/h. Each of the crushers will process 3,694 t/h. The stationary crusher will be located to the south of the pit, while the semi-mobile crusher will be located inside the pit.

The mill feed will be crushed to 80% passing 120 mm or finer by the two crushers depending on its particle size. Each of the crushing stations will be equipped with one rock breaker to break oversize rocks. In addition, dust collectors will be provided at the crushing facilities to control fugitive dust generated during crushing and transporting.

The main equipment and equipment features of the crushing facilities will be as follows:

- A stationary crushing facility, including:
- One 1.52 m by 2.79 m gyratory crusher;
- One hydraulic rock breaker;
- One 2.13 m wide by 10.0 m long apron feeder;
- One 1.52 m wide by 326 m long belt conveyor.

- A semi-mobile crushing facility, including:
- One 1.52 m by 2.26 m in-pit semi-mobile gyratory crusher;
- One hydraulic rock breaker;
- One 2.14 m wide by 25 m long in-pit apron feeder;
- One 1.83 m wide belt conveyor.
- One 1.52 m wide by 261 m long belt conveyor.

The crushed mill feed from the two crushing facilities will be conveyed to a 120,000 t live capacity stockpile. Dust collection systems will be installed to control the spread of the fugitive dust generated during the crushing and the mill feed transport at the crushed mill feed re-handling areas.

Coarse Mill Feed Stockpile
The coarse mill feed stockpile will have a live capacity of 120,000 t. The received material will be reclaimed from the stockpile by eight 1.52 m wide by 7.60 m long apron feeders at a nominal rate of 1,004 t/h per feeder. The stockpile reclaim area will also be equipped with a dust collection system to minimize the spread of dust generated during mill feed transport. The reclaimed mill feed from the apron feeders will be discharged onto two 1.52 m wide by 670 m long SAG mill feed conveyors.

Grinding and Classification
Two SABC circuits are proposed to grind the coarse mill feed to 80% passing 150 µm. On average, each of the SABC circuits will be capable of processing 3,012 t of the coarse mill feed per hour.

Primary Grinding and Classification
There will be two primary grinding circuits; each of the circuits will consist of one SAG mill and one vibrating screen, operating in a closed circuit with pebble (cone) crushers. The major pieces of the primary grinding and crushing equipment will be as follows:
- Two 12.20 m diameter by 7.01 m EGL SAG mills, each with one 22.5 MW gearless motor drive;
- Two 3.66 m wide by 7.30 m long vibrating screens;
- Three cone crushers, each powered by one 750 kW motor.
The coarse mill feed from two conveyors will be separately fed to the two SAG mills. The SAG mills will be equipped with 76 mm pebble ports for the removal of undersize material, including critical-size pebbles. The mill discharge from each SAG mill will be screened by a SAG mill trommel and then a vibrating screen. The trommel and screen undersize will flow by gravity to a sump and be pumped to the secondary grinding circuits. The oversized material from the two screens will be separately conveyed to a common pebble crusher feed surge bin. An automatic ball charge device will add grinding balls into the SAG mills at a controlled rate.

The pebble surge bin will have a capacity of 1,500 t. The pebbles will be reclaimed by three retrievable belt feeders to three cone crushers, which will crush the pebbles to 80% passing 12.5 mm. The crushed pebbles will be directed onto the SAG mill feed conveyors, which will carry the crushed pebbles and coarse mill feed to the SAG mills. To protect the cone crushers, each pebble surge bin feed conveying train will be equipped with two magnets and one metal detector for removal of any metals. Lime slurry will be added to the SAG mills to adjust the flotation feed slurry pH.

Secondary Grinding and Classification
The undersize material from each primary grinding circuit will be pumped to the cyclone feed pump box in the secondary grinding circuit. The SAG mill product, together with the ball mill discharge, will be pumped to cyclone clusters. The cyclone underflow will flow by gravity to the ball mills, while the cyclone overflow with a solid density of approximately 35% w/w will be sent to downstream bulk flotation circuits.

The secondary grinding circuit will include four ball mills, each in closed circuit with one cyclone cluster. The grinding circuits will further grind the SAG mill products to 80% passing 150 µm. The major equipment in the secondary grinding circuits will include the following main features:
- Four 8.23 m diameter by 13.72 m EGL ball mills, each driven by two 10.0 MW dual-pinion motors;
- Four cyclone clusters, each consisting of ten 840 mm diameter cyclones (seven operating, three in standby).

Two separate automatic ball charging systems will be provided to charge grinding media to the ball mills. Collectors (FO and SEX) will be added to each of the ball mill pump boxes.

The proposed processing plant is designed to process the Schaft Creek mineralization at a nominal throughput of 133,000 t per day (t/d) (with an availability of 92%) to produce market-grade copper and molybdenum concentrates.

A conventional flotation process is proposed for the Project. The processing plant will consist of the following:
- Primary crushing at the mine site;
- A crushed mill feed stockpile;
- A main processing plant, including;
- Two primary grinding circuits, consisting of two SABC circuits;
- Two copper-molybdenum bulk flotation circuits;
- One copper and molybdenum separation circuit, including molybdenum concentrate leaching to reduce copper and lead contents in the final molybdenum concentrate;
- Concentrate dewatering;
- Tailings disposal.

Flotation
The ground mill feed slurry will be processed by conventional flotation to recover the valuable minerals. The flotation will consist of bulk flotation ........