Historic gold mining in Nova Scotia, including mining in the Moose River Gold District, has focussed on quartz-vein hosted gold deposits within the Goldenville Formation, typically associated with the limbs and hinges of anticlines. This setting is often referred to as ‘Meguma style’ gold mineralization and a number of workers have drawn parallels with a similar style of gold mineralization in the Victorian Goldfields of eastern Australia (e.g. Christie et al, 1999).

In recent years the existence of disseminated gold mineralization and potential to develop large tonnage, open-pitable resources in Nova Scotia has been recognised, particularly since 1986-87 when drilling around old workings at Moose River Gold Mines intersected wide intervals of relatively low grade gold mineralization in what is now known as the Touquoy gold deposit. Since then, disseminated gold mineralization has been identified at a number of locations, spatially associated with anticlinal fold hinges. Most of that mineralization is associated with argillites or mixed greywacke-argillite units within the Goldenville Formation, including Touquoy, Beaver Dam and Fifteen Mile Stream; however, disseminated gold has also been recognised in greywacke host rocks within the Goldenville Group at North Brookfield and several other sites.

Gold mineralization in Nova Scotia is temporarily linked to the waning stages of the Acadian Orogeny, coincident with basement metamorphism and granite intrusion. Absolute ages of 370 and 407 Ma have recently been defined for arsenopyrite associated with gold mineralization at two widely spaced sites in Nova Scotia with the implication that gold mineralization occurred as multiple events and/ or over a long time span (Morelli et al, 2005).

Mining is based on conventional open pit methods suited for the project location and local site requirements. The mining fleet will include diesel powered down the hole (DTH) drills with 144 mm bit size for production drilling, diesel-powered RC drills for bench-scale grade control drilling, 5 m3 bucket size diesel hydraulic excavators and 7 m3 bucket sized wheel loaders for production loading, and 64 t payload rigid-frame haul trucks and 41 t articulated trucks for production hauling, plus ancillary and service equipment to support the mining operations. In-pit dewatering systems will be established for each pit. All surface water and precipitation in the pits will be handled by submersible pumps.

Mine operations will continue at Touquoy and will move to Beaver Dam once the Touquoy open pit is exhausted in 2023. At Touquoy, ore is hauled to a crusher 700 m north of the pit, which feeds the process plant; and waste rock is deposited into a waste rock storage facility (WRSF) 1,000 m east of the pit, or is used as rock fill in construction of the TMF that is located 800 m east of the pit.

At Beaver Dam, ore will be hauled to a crusher that will be located 600 m south of the pit, and then crushed ore will be hauled by on-highway haulers from Beaver Dam to the process plant at Touquoy operations; and waste rock will be deposited into WRSFs to be situated 650 m south and 1,650 m west of the pit. Mine planning and mining cost estimates are limited to the mining and delivery of ore to the crusher and waste rock to the planned destinations. The haul of ore from Beaver Dam to Touquoy is not covered under the mine plan or mining costs.

Two independent stand-alone open pit operations at Fifteen Mile Stream and Cochrane Hill will run concurrently with the Touquoy and Beaver Dam operations. At Fifteen Mile Stream, ore will be hauled to a crusher that will be located 1,500 m southeast of the pit, which will feed the process plant. Waste rock will be split into potentially acid-generating (PAG) and non-potentially acid generating (NPAG) material and deposited into WRSFs to be situated 700 m south of the pit or will be used as rock fill in construction of the TMF to be located 1,700 m east of the pit.

At Cochrane Hill, ore will be hauled to a crusher to be situated 1,200 m east of the pit, which will feed the process plant. Waste rock will be split into PAG and NPAG material and will be deposited into a WRSFs to be located 700 m north of the pit or will be used as rock fill in construction of the TMF that will be situated 1,300 m southeast of the pit.

Ultimate pit limits are split into phases or pushbacks to target higher economic margin material earlier in the mine life:

• The Touquoy pit is split into north, south and east phases with the higher-grade, lower strip ratio north phase mined ahead of the south and east phase pushbacks. From the start of 2019 a 4.5-year pit production schedule is developed;

• The Beaver Dam ultimate pit is subdivided into two phases, south and north, but for considerations of vertical advance the pit is mined as one phase from top to bottom. The Beaver Dam material adds another 3.5 years to the pit production schedule;

• At Fifteen Mile Stream, the Egerton–MacLean pit is split into south and north phases with the higher-grade and lower strip ratio south phase mined ahead of the north phase. The Hudson and Plenty pits are mined as one phase each. Starting in 2021 an 8.5-year mine production schedule is developed;

• The Cochrane Hill pit is split into south and north phases with the higher-grade south phase mined ahead of the north phase. A starter phase is also designed to provide waste rock construction materials to the starter tailings dam. Starting in 2022 an eight-year mine production schedule is developed.

During the pre-stripping phase of mine operations, all ore mined in the pit will be stockpiled. Throughout the life of operations, all ore grading between 0.30 and 0.50 g/t Au will be stockpiled. As of December 31, 2018, the existing Touquoy stockpiles hold 2.4 Mt of ore grading 0.57 g/t Au. The stockpiles will accommodate and additional 1.5 Mt at Touquoy, 4.8 Mt at Cochrane Hill, and 6.0 Mt at Fifteen Mile Stream. The stockpiled Mineral Reserves are planned to be re-handled back to the crusher once the pits are exhausted.

Mining operations will be based on 365 operating days per year with two 12 hour shifts per day. An allowance of 12 days of no mine production has been built into the mine schedule to allow for adverse weather conditions.

Maintenance on mine equipment will be performed in the field with major repairs to mobile equipment in the shops located near the plant facilities.

Annual mine operating costs per tonne mined range from $2.60–$4.10/t with a LOM average of $3.00/t mined (including capitalized pre-production). Mine operations will include ore control and production drilling, blasting, loading, hauling, and pit, haul road nd WRSF maintenance functions. Mobile equipment maintenance operations will also be managed by the Owner and are included in the mine planning and costs. Lease and finance charges on mobile equipment are also included in the mine operating cost estimate.

After mining is completed, the mining equipment will be removed, and the pits will be allowed to fill with water producing ponds. Contouring and re-vegetation of the fill areas will be completed. All mine buildings will be removed.

The Touquoy process plant is designed for an ore treatment of 2 Mt/a or 250 t/h based on an availability of 8,000 h/a, or 91.3%. However, the crushing section design is set at 60% availability since it operates outdoors and uses modular semi- mobile equipment. It will accept Touquoy ROM ore for the first five years of operation and thereafter ROM ore from the Beaver Dam deposit at the same treatment rate using the same unit operations. Only relatively minor equipment modifications are expected to be needed at Touquoy to treat the Beaver Dam ore.

The main plant building houses the grinding, gravity recovery, reagent, elution and refinery sections. The crushing and CIL sections are located outdoors. The three-stage crushing circuit ahead of a single-stage ball mill is based on modular semi-mobile crushing equipment so as to allow the modifications necessary to allow the introduction of Beaver Dam ore.

ROM is hauled from the Touquoy pit to the primary crusher and tipped over a static grizzly sloped to bring oversize back to the loading side for removal by a front-end wheel loader (FEL). The FEL supplements the direct-tip feed from the Touquoy ROM stockpiles to maintain a continuous crushing operation. Mine operations retrieve any oversize and either use a mobile rock breaker to reduce the lump size or return oversize to the pit.

The mobile crushing plant produces a fine ore sized to a P80 of 10 mm. The throughput of the crushing plant package is 381 t/h at a crushing plant availability of 60%.

The fine ore product is conveyed to a fine ore stockpile (12,000 t capacity; live volume of 3,000 t). Two variable-speed reclaim slot belt feeders provide two live pockets and an estimated 25% natural reclaim of the stockpile. The fine ore feed to the mill is conveyed by a 95 m long covered mill feed conveyor from the two fine ore reclaim feeders to the mill feed chute.

The mill is sized to handle both the Touquoy and Beaver Dam ores without any mechanical adjustment required during the transition between mines. The Touquoy ore is expected to operate at a lower ball volume and steel ball consumption than Beaver Dam ore to compensate for the difference in hardness and abrasion characteristics.

Mill slurry discharge overflows onto a rubber- lined trommel screen with trommel oversize discharging to a bunker for regular collection and disposal. The trommel undersize gravitates to the cyclone feed hopper where the slurry is diluted with process water and pumped with a duty/standby cyclone feed pump to the cyclone cluster. A density meter monitors and controls the amount of process water required to produce a target density to the cyclones.

The cyclone underflow splits, with up to 30% feeding the gravity circuit and the remaining underflow stream gravitating to the ball mill. The cyclone produces a fine ground overflow product of P80 150 µm which is sampled, and then gravitates to the vibrating trash screen. Oversize debris are removed and falls to a trash bin at ground level. The minus 0.8 mm trash screen underflow flows by gravity to the CIL circuit.

A portion of the ball mill circulating load is fed into two 50% duty parallel gravity concentrator trains. The gold concentrate recovered is treated in an intensive batch leach system designed to handle 2.4 t/d of concentrate. The resulting concentrated gold solution is pumped to a dedicated eluate tank at the gold room.

The intensive cyanidation circuit receives the periodic gold concentrate for treatment in an intensive leach reactor. The gold-containing pregnant solution is pumped periodically to a dedicated eluate tank in the gold room.

The trash screen underflow enters the pre-leach feedwell after mixing with metered flocculant. The feed box slurry gravitates to the leach tank and optionally can feed directly to CIL Tank 1.

The circuit is a hybrid CIL type and consist of one leach tank and six adsorption tanks in series, each having a live volume of 1,169 m3. The design allows for a 250 t/h solids feed rate at 50% solids for an average 24-hour residence time. Each tank is interconnected with launders to allow slurry to flow sequentially by gravity to each tank in the train.

Barren carbon enters the adsorption circuit at CIL Tank 6. The carbon advances countercurrent to the main slurry flow during periodic transfers of slurry and carbon using air lift movement from a downstream to upstream tank. Carbon concentrations of 10 to 15 g/L are required in all tanks. Carbon is retained in the upstream tank by an intertank screen. The countercurrent process is repeated until the carbon becomes loaded and reaches CIL Tank 1. Then a recessed impeller pump transfers slurry and carbon to a loaded carbon recovery screen. The loaded carbon is washed with water and released to the acid wash column located inside the main plant, in the desorption area. The slurry returns to CIL Tank 1.

Following elution of the loaded carbon and thermal regeneration, the barren carbon is screened and reported to CIL Tank 6. Fine carbon is discarded to the CIL tailings hopper.

The pressure Zadra elution circuit (elution column, strip solution tank, strip solution pump and a strip solution heater package) operates in a closed loop with the electrowinning cells located inside the gold room.

Three electrowinning sludging cells are used; one cell is dedicated to the intensive cyanidation circuit and the other two cells to the elution circuit.