Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Dewatering
- Gravity separation
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Hydrochloric acid (reagent)
- INCO sulfur dioxide/air process
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Carbon adsorption-desorption-recovery (ADR)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 2030 |
Atlantic Operations consists of Touquoy open pit, along with three additional planned projects nearby at Beaver Dam, Fifteen Mile Stream and Cochrane Hill. |
Latest News | Atlantic Gold Files NI 43-101 Technical Report May 9, 2019 |
Source:
p. 100
On 14 September 2020, the Group, through its subsidiary Atlantic Mining Nova Scotia, acquired the remaining 93% of the issued shares of Moose River Resources Incorporated (“MRRI”) resulting in 100% St Barbara ownership.
Deposit Type
- Vein / narrow vein
- Mesothermal
Summary:
The known deposits within the Project area are considered to be examples of turbiditehosted mesothermal gold deposits.
The Meguma Terrane of Nova Scotia hosts the Moose River Member, Tangier Member, and Taylors Head Member of the basal greywacke-dominated Goldenville Formation. Gold mineralization is generally hosted in argillite and/or greywacke sequences of the Moose River Member and is associated with regional-scale anticlines. Structural repetition due to folding and faulting may result in thickening of gold-bearing units. Gold occurs as native gold, and has been observed in a number of settings, including along shear cleavage, hair line fractures; in pressure shadows; as inclusions; on the margins of sulphide grains; in thin, bedding-parallel quartz veins and stringers. Mineralization is associated with sulphides, including arsenopyrite, pyrite and pyrrhotite. Lesser chalcopyrite, galena, and sphalerite have been observed.
Summary:
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.
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.
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.
Flow Sheet:
Crusher / Mill Type | Model | Size | Power | Quantity |
Jaw crusher
|
|
|
|
1
|
Mobile crusher(s)
|
|
|
|
1
|
Ball mill
|
|
4.9m x 8.1m
|
3300 kW
|
1
|
Summary:
Touquoy
The Touquoy process plant is located east of Moose River, northeast of the Touquoy open pit and northwest of the TMF.
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.
Crushing
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 vibrating grizzly feeder feeds the primary jaw crusher at the front of the mobile crushing circuit. The oversize from the vibrating grizzly enters the single toggle jaw crusher. A tramp magnet removes steel trash from the primary crushed ore.
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 fine ore is processed through one single pinion ball mill in closed circuit with hydrocyclones producing a final product of P80 150 µm. The mill has a nominal solids throughput of 5,479 t/d and can process 250 t/h at 91.3% availability. The overall ball mill circulating load is 250%.
Grinding
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.
Beaver Dam
A new, simple, satellite primary crushing facility consisting of a grizzly feeder, jaw crusher and primary coarse ore stockpile feed conveyor will be required at Beaver Dam.
The primary jaw crusher module (jaw crusher and grizzly feeder) will be relocated from Touquoy and installed at the Beaver Dam crushing station before Year 6. A coarse ore stockpile feed conveyor will be added, and a new Beaver Dam ROM hopper will be installed at the Beaver Dam crusher station. The main plant will undergo minor retrofits between the Touquoy ROM hopper and secondary crushing section to receive the primary crushed ore.
Primary crushing will occur at Beaver Dam to provide a primary crushed ore stockpile with two days live volume equivalent to 11,000 t capacity. This stockpile inventory will buffer a commercial ore transport road truck fleet hauling the primary crushed ore to the feed point of the main plant. A fleet of 22 trucks each having a nominal payload of 31 t and requiring nine cycles per day/truck will deliver the daily tonnage requirement to meet the Touquoy mill demand.
Processing
- Dewatering
- Gravity separation
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Hydrochloric acid (reagent)
- INCO sulfur dioxide/air process
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Carbon adsorption-desorption-recovery (ADR)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
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.
Gravity and Intensive Cyanidation
A portion of the ball ........

Recoveries & Grades:
Commodity | Parameter | 2021 | 2020 | 2018 |
Gold
|
Recovery Rate, %
| ......  | ......  | 94.9 |
Gold
|
Head Grade, g/t
| ......  | ......  | 1.41 |
Reserves at June 30, 2021:
Ore Reserves Cut-off Grades: 0.3 g/t Au – 0.4 g/t Au.
Mineral Resources Cut-off Grades: 0.3 g/t Au.
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
Stockpiles
|
6,400 kt
|
Gold
|
0.5 g/t
|
97 koz
|
Proven
|
In-Situ (OP)
|
21,210 kt
|
Gold
|
1.1 g/t
|
778 koz
|
Probable
|
In-Situ (OP)
|
22,270 kt
|
Gold
|
1.1 g/t
|
781 koz
|
Proven & Probable
|
Stockpiles
|
6,400 kt
|
Gold
|
0.5 g/t
|
97 koz
|
Proven & Probable
|
In-Situ (OP)
|
43,480 kt
|
Gold
|
1.1 g/t
|
1,558 koz
|
Measured
|
In-Situ (OP)
|
23,471 kt
|
Gold
|
1.1 g/t
|
838 koz
|
Indicated
|
In-Situ (OP)
|
30,196 kt
|
Gold
|
1 g/t
|
1,004 koz
|
Inferred
|
In-Situ (OP)
|
7,026 kt
|
Gold
|
1.1 g/t
|
249 koz
|
Total Resource
|
In-Situ (OP)
|
60,693 kt
|
Gold
|
1.1 g/t
|
2,091 koz
|
- Subscription is required.