Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Gravity separation
- Carbon re-activation kiln
- Intensive Cyanidation Reactor (ICR)
- INCO sulfur dioxide/air process
- Agitated tank (VAT) leaching
- Concentrate leach
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 2023 |
Since 2019 mine's production and financial results have been included into the Atlantic Gold operations. |
Latest News | St Barbara to expand Canadian foothold with $63m takeover July 28, 2020 |
Source:
p. 5,100
The acquisition of Moose River Resources Incorporated (MRRI), in July 2020 saw St Barbara own 100% of the Touquoy Mine and surrounding exploration tenements.
Deposit Type
- Mesothermal
- Sediment-hosted
- Orogenic
Summary:
The known deposits within the Project area are considered to be examples of turbidite-hosted, orogenic mesothermal gold deposits.
A number of argillite units, separated by greywackes, occur within the Touquoy property. Mineralization is hosted within the Touquoy argillite unit of the Moose River Formation of the Goldenville Group. The argillite is folded around the Moose River–Fifteen Mile Stream Anticline, a regional structure that can be traced for at least 47 km from a position approximately 6 km south west of the Touquoy deposit, to approximately 4 km northeast of Fifteen Mile Stream.
The anticline geometry varies along its length in the property area, from an upright tightly-folded anticline in the vicinity of the Touquoy deposit to multiple tight folds, overturned to the north, in the Stillwater area.
The argillite unit is as much as 180 m thick close to the hinge in the northern limb and appears to thin with depth. It is much thinner in the southern limb, typically 25–60 m wide. In the northern limb, the Touquoy argillite is separated into upper and lower units by a distinctive marker horizon, the rip-up unit, which varies from a thin (<2 m thick) horizon of sparse sandstone rip-up clasts in a finer grained matrix to a fine or medium grained greywacke. The rip-up unit has only rarely been recognized in the southern limb.
The Moose River–Fifteen Mile Stream Anticline is tightly folded and upright to overturned with both limbs dipping north. The anticline hinge is doubly-plunging, with shallow plunges to both northeast and southwest. It has been disrupted by a number of northwest-trending faults with contrasting fold geometries occurring on opposite sides of some of those faults showing that folding and some of the faulting had similar timing.
Two major faults appear to have a significant effect on mineralization thickness at Touquoy, the curvilinear West Fault and the relatively planar Northeast Fault:
• The West Fault is interpreted to show normal movement such that the anticline to the east of the fault has dropped and argillite on the southern limb of the anticline, west of the West Fault shows relative displacement to the south;
• The Northeast Fault comprises an approximately 10 m to 20 m wide zone with intensely faulted and fragmented intervals separated by weakly sheared or quite coherent intervals. It juxtaposes a sequence of barren or very weakly goldanomalous argillite and greywacke against the Touquoy argillite and its hanging wall units.
A discrete structure (or structures) parallel to the anticline axial surface and representing a hinge fault or faults has been tentatively identified in several drill sections, and may have a role in localising gold mineralization.
A series of north- to northeast-trending and east- to northeast-trending faults have displaced both stratigraphy and gold mineralization, although it is possible that some of these faults were also active during gold mineralization.
A well-developed axial plane cleavage is recognised within argillite layers while greywacke layers exhibit weakly developed pressure solution cleavage. Flexural slip occurred during folding and disruptions in bedding orientation in the hinge position is interpreted to reflect repetition (crumpling) of the fold hinge, to produce parallel fold axes at Touquoy.
The Touquoy host rocks have been metamorphosed to lower greenschist facies such that the dominant mineral assemblage in the argillites is quartz, muscovite, chlorite ± albite, with accessory ilmenite and rutile.
Gold mineralization is best developed in the northern limb of the anticline where it broadly conforms to bedding over a strike length of approximately 600 m. Mineralization is less persistent in the anticlinal hinge but is well developed in the southern limb over a strike length of approximately 250 m where a bedding control is less apparent but where mineralization is associated with shearing near the contact between the Touquoy argillite and hanging wall Touquoy greywacke.
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 where it is often associated with pyrite or pyrrhotite and sometimes with base metal sulphides, particularly galena and chalcopyrite; and on the margins of tightly-folded quartz veins, often at, or close to, fold hinges.
Gold grain size as indicated by petrographic studies varies from 1 µm to >1 mm and gold grains up to 1.5 mm in size have been observed. Sulphide minerals accompanying the gold mineralization are pyrrhotite, usually aligned along the axial plane cleavage (1–2%), arsenopyrite, often as coarse porphyroblasts (1%) and pyrite (<1%). Other sulphides are rare. At a macro scale, there is typically poor correlation between arsenic and gold content.
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.
Pit designs are configured on 10 m bench heights, with 8m wide berms placed every two benches, or double benching. Bench face angles, and subsequent inter-ramp angles are varied based on prescribed azimuths and depth from surface, as specified by each geotechnical report.
The pit slope criteria for Touquoy are based on a 2011 geotechnical report by Peter O’Bryan & Associates (O’Bryan, 2011). The shallower slopes at the 60 m depth are based on the requirement for a 15 m wide catch berm at this bench.
Flow Sheet:
Crusher / Mill Type | Model | Size | Power | Quantity |
Jaw crusher
|
|
|
|
1
|
Cone crusher
|
|
|
|
2
|
Ball mill
|
|
4.9m x 8.1m
|
3300 kW
|
3
|
Summary:
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
Processing
- Gravity separation
- Carbon re-activation kiln
- Intensive Cyanidation Reactor (ICR)
- INCO sulfur dioxide/air process
- Agitated tank (VAT) leaching
- Concentrate leach
- Carbon in leach (CIL)
- 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 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.
Gravity and Intensive Cyanidation
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 equipment is arranged to provide a gravity cascade under the ........

Recoveries & Grades:
Commodity | Parameter | 2021 | 2020 | 2019 | 2018 |
Gold
|
Recovery Rate, %
| ......  | ......  | | 94.9 |
Gold
|
Head Grade, g/t
| ......  | ......  | ......  | 1.41 |
Reserves at February 15, 2019:
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
Stockpiles
|
2.41 Mt
|
Gold
|
0.57 g/t
|
|
Proven
|
In-Situ (OP)
|
3.36 Mt
|
Gold
|
1.1 g/t
|
|
Probable
|
In-Situ (OP)
|
7.14 Mt
|
Gold
|
1.28 g/t
|
|
Measured
|
In-Situ (OP)
|
3.4 Mt
|
Gold
|
1.14 g/t
|
124.3 koz
|
Indicated
|
In-Situ (OP)
|
7.86 Mt
|
Gold
|
1.27 g/t
|
320.7 koz
|
Measured & Indicated
|
In-Situ (OP)
|
11.26 Mt
|
Gold
|
1.23 g/t
|
445.1 koz
|
Inferred
|
In-Situ (OP)
|
1.14 Mt
|
Gold
|
1.3 g/t
|
47.8 koz
|
Commodity Production Costs:
| Commodity | Units | 2021 | 2020 | 2018 |
Cash costs
|
Gold
|
CAD
|
|
|
558 / oz
|
Total cash costs
|
Gold
|
AUD
|
...... †
|
...... †
|
|
All-in sustaining costs (AISC)
|
Gold
|
CAD
|
|
|
731 / oz
|
All-in sustaining costs (AISC)
|
Gold
|
AUD
|
...... †
|
...... †
|
|
† Net of By-Product.
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Financials:
| Units | 2021 | 2020 | 2018 |
Sustaining costs
|
M
| ......  | ......  | 9.1 CAD |
Revenue
|
M
| | | 128.3 CAD |
Operating Income
|
M
| | | 55.9 CAD |
After-tax Income
|
M
| | | 27.9 CAD |
Operating Cash Flow
|
M
| | | 69.6 CAD |
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