Canada

Bateman - F2 Project

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Categories

Overview

Mine TypeUnderground
StageConstruction
Commodities
  • Gold
Mining Method
  • Mechanized Cut & Fill
  • Sub-level Retreat
  • Uppers Retreat
  • Alimak
Backfill type
  • Cemented paste backfill
  • Unconsolidated rockfill
Shaft Depth 730 m
Mine Life7 years (as of Jan 1, 2020)
SnapshotThe Red Lake Operation operates three different historical underground mines (Red Lake, Campbell and Cochenour) and two processing facilities (Red Lake and Campbell Mills). The recently acquired Bateman Gold Project has added a fourth orebody and a third processing plant, resulting in a consolidated mining region with numerous opportunities to maximise production and margins. Data integration and re-modelling of the Bateman orebody is underway.

The Project property has never been in commercial production to date, though several bulk samples have been taken in the past from the F2 Gold Deposit.

The 31 December 2021 Evolution Bateman Mineral Resource estimate is 5.1Mt at 4.60g/t gold totalling 757koz of in situ gold. The Mineral Resource is based on an updated geological interpretation and block model estimate for the F2 deposit.
Related AssetRed Lake Operation

Owners

SourceSource
CompanyInterestOwnership
Evolution Mining Ltd. 100 % Indirect
On 19 May 2021, Evolution completed the acquisition of Battle North Gold Corporation. Battle North Gold's assets include the Bateman Gold Project.

Contractors

ContractorContractDescriptionRef. DateSource
unawarded or unknown Mining Over the LOM, use contractors for Mass Blast Raise Mining (MBRM). Dec 10, 2020
unawarded or unknown Drilling Over the LOM, use contractors for Longhole blasthole drilling. Dec 10, 2020

Deposit type

  • Vein / narrow vein
  • Orogenic
  • Mesothermal

Summary:

Deposit Types
The F2 Gold Deposit has multiple characteristics that are compatible with orogenic-style gold mineralization and deposits, also referred to as mesothermal gold, or Greenstone-hosted quartz carbonate vein gold. The characteristics that the F2 Gold Deposit shares with that deposit type include a spatial association with a district- to regional-scale fault zone, mineralization associated with sometimes complex networks of quartz-carbonate veins that are hosted by steeply dipping brittle ductile shear zones and faults, greenschist to amphibolite-grade host rocks and extensive silica and carbonate alteration (DubÈ & Gosselin, 2007). Orogenic-style gold mineralization is typically related to the circulation of metamorphic fluids generated during tectonic accretionary processes. The deposits are characterized by strong lithological and structural controls and are hosted in deformed and metamorphosed volcanic, sedimentary, and granitoid rocks occurring across a range of crustal depths (Groves et al., 1998).

Orogenic gold deposits are widely distributed in the Neoarchean greenstone belts of the Superior, Churchill, and Slave provinces in Canada and occur in younger terranes such as the Neoproterozoic Birimian terranes of the West African Craton (Goldfarb et al., 2017) and the Cordilleran and Appalachian terranes of North America (Goldfarb et al., 2001). In Canada, the most important concentration of orogenic gold deposits occurs in the greenstone belts of the southern Superior Province.

Mineralization at the F2 Gold Deposit shares attributes with other orogenic gold deposits of the Red Lake mining district where most of the gold production is derived from orogenic-style high- grade quartzcarbonate veins that are associated with deformation of the Balmer Assemblage mafic and ultramafic volcanic rocks. At the CampbellRed Lake Mines, located to the south of the Project, a spatial relationship exists between gold mineralization and contacts between mafic and ultramafic rocks and DubÈ et al. (2001) suggested that competency contrasts between the mafic (basalt) and ultramafic (komatiitic basalt) units played an important role in localizing deformation, and in controlling the circulation of gold-bearing fluids, the formation of veins and the deposition of gold. It is likely that competency contrasts between the High-Ti Basalt panels and the surrounding Ultramafic units would have also played a similarly important role during deformation of the Balmer assemblage rocks and gold deposition at the F2 Gold Deposit. At the CampbellRed Lake Mines, the mineralized quartzcarbonate veins are associated with the Campbell and Dickenson fault zones that coincide with transposed limbs of F2 folds and also with hinge zones of F2 folds (DubÈ et al., 2002).

Project Mineralization
Gold mineralization occurs primarily within panels of High-Ti Basalt in the form of mineralized quartz ± carbonate ± actinolite veins with variable sulphide contents, within quartz-breccia zones and in association with disseminated sulphides hosted by zones of silica alteration and veining. Lesser amounts of similar styles of mineralization are also hosted within the Felsic Intrusive units. Previous studies (SRK, 2013a) have identified an earlier low-grade gold mineralization event, and a later, overprinting, higher-grade gold mineralization event.

The early low-grade gold mineralization event is thought to have formed pre- to syn-D1 as the mineralization is overprinted by the S1 foliation. The early phase of mineralization is generally low-grade, with gold grades generally less than 4.0 g/t Au and occurs as quartz ± actinolite ± carbonate veins and stringers and as disseminated mineralization associated with quartz–biotite–sulphide alteration in the High-Ti Basalt and Felsic Intrusive units (Golder, 2018a).

The higher-grade second mineralization event is associated with shear-related veins and minor localized shear zones and breccias that are interpreted to have formed as a result of D2 dextral transpression along the EBDZ. The gold mineralization occurs in association with disseminated sulphide mineralization in the High-Ti Basalt and also in gold-bearing quartz ± actinolite ± carbonate veins (V2) in the High-Ti Basalt and Felsic Intrusive units (Golder, 2018a).

Quartz veins are scarce within the Ultramafic Flow units in comparison to the veins in the High-Ti Basalt and Felsic Intrusive units. Quartz veins occurring in the Ultramafic Flow units generally occur in isolated areas, are thin (several centimetres wide) and pinch out with lengths less than several metres, possibly due to isoclinal folding and boudinage within the highly sheared Ultramafic units. The quartz veins in the Ultramafic Flow units generally lack associated gold mineralization.

Quartz veins are common in the High-Ti Basalt, where they often occur as vein sets comprising multiple parallel and closely spaced veins. The veins are generally present throughout most of the High-Ti Basalt, with mineralization concentrated in areas where veins are more abundant.

Quartz veins are present in the Felsic Intrusive units but are not as common as in the High-Ti Basalt and do not generally have the same associated elevated gold grades as observed in the High-Ti Basalt. The Felsic Intrusive unit and the High-Ti Basalt both likely underwent brittle-ductile to brittle deformation resulting in the development of structural traps controlling the emplacement of quartz veins. However, the quartz–feldspar porphyry did not provide the same chemical trap as did the more iron-rich (relative to the Felsic Intrusive units) High-Ti Basalt. This did not allow for abundant gold mineralization to develop in the Felsic Intrusive units compared to the High-Ti Basalts.

Reserves at December 31, 2021

Mineral Resource Statement Reported at 2.5 g/t Au Cut-off Grade.
CategoryTonnage CommodityGradeContained Metal
Indicated 2.1 Mt Gold 4.93 g/t 335 koz
Inferred 3 Mt Gold 4.37 g/t 422 koz
Total Resource 5.1 Mt Gold 4.6 g/t 757 koz

Mining Methods

  • Mechanized Cut & Fill
  • Sub-level Retreat
  • Uppers Retreat
  • Alimak

Summary:

The Bateman Gold Project is an underground development project acquired from Battle North Gold in May 2021. It consists of the high-grade F2 Gold Deposit, more than 14,000m of underground development including a commissioned shaft to approximately 730m below surface, a surface decline that connects to the underground workings, and surface infrastructure including a 650ktpa plant (permitted to 450ktpa), a tailings dam facility, electric power supply and substation, 200-person camp, earth-works and civil-works.

The Feasibility Study mine plan for the F2 Gold Deposit is based on a shaft and ramp-accessed underground mining operation producing an average of 1,250 t/d of ore from bulk and selective mining methods, including, uppers, mass blast raise mining (MBRM), longhole (LH) and cut-and-fill (C&F). Bulk methods average $98/t, and C&F - the only selective method - averages $163/t.

The Project development plans starts with six months (2,010 m) of lateral and vertical development prior to commencement of Pre-CP. During this period to the following is planned:
- Excavate decline connecting surface to the 122 m Level.
- Excavate two partially completed ramps between 305 m Level to 122 m Level to allow mine-wide equipment travel down to the 305 m Level.
- Develop a fresh air raise from the 610 m Level to the 305 m Level to allow lower mine development.

Following the 6-month development period, the 15-month Pre-CP starts to ramp-up production from 250 t/d to 900 t/d. In parallel, development crews will advance another 5,145 m laterally below the 305 m Level as well as perform vertical raise development (271 m) for return air raise from the 366 m Level to the 122 m Level.

By the end of LOM, the ramp will connect a total of 18 main levels, 61 m intervals, and 12 sub-levels of various interval spacing. Shaft access will be via 6 of the 18 main levels, specifically 122 m, 183 m, 244 m, 305 m, 610 m, and 685 m Levels.

Paste backfill, produced in a paste backfill plant in the Mill, will be made from a mixture of tailings and binder, 3 to 5%, and will be the primary backfill material.

Unconsolidated waste rock from development headings will be used to augment backfill where possible. Ore and waste will be direct loaded, on main levels, by load-haul-dump (LHD) into 50-t battery trucks. These 50-t battery trucks will either transport to surface via the main ramp or to the 610 m Level ore and waste rock-breaker/grizzly dumps. These dumps are equipped with remote operated rock-breakers will material passing through 300 mm grizzlies. The ore or waste material then is loaded onto a conveyor system on the 685 m Level, which transports the material out to the shaft loading pocket, where it is hoisted to surface. Whether hauled to surface by truck or hoisted in the shaft, ore will be crushed to <150 mm by a surface crusher prior to being conveyed to the processing facility.

Four mining methods were selected: longitudinal LH, uppers, C&F, and MBRM. These methods are industry-proven applications with favourable geometrical parameters for use on the Project resource.

Longhole Retreat
This bulk mining method is applied to ore widths of 3 m and greater. It involves developing the ore body at regular vertical intervals (sub-levels), typically every 30 m. LH will be used to mine 141 (35%) of the LOM stopes and account for 2.2 million (62%) of total tonnes.

Stope sills will be excavated from working levels. A blasting slot would be developed at one end of the excavation, and mining of the blocks would retreat along the stope strike. Mucking takes place within the undercut of the mining block via remote-controlled LHD equipment. The strike length is dictated by wall stability in the open stope and is initially determined by empirical design.

Uppers Method
This proven method involves driving a drift along the strike of the mineralized zone, positioning an inverse (slot) raise at the stope extremity, and production drilling of up holes, as high as 15 m, and dumped 70° towards the slot. Blasting and mucking would retreat towards the stope entrance. These stopes may or may not be backfilled. Uppers accounts for 141 (35%) of the LOM stopes and yield 0.6 million (16%) of total tonnes.

This method is best used where ore continuity is known, and stope height is limited. Often used in conjunction with LH mining, the method can be used separately as part of an overall mining strategy.

Mechanized Cut-and-Fill
C&F is a moderately productive, highly selective method for excavation of stope widths between 1.8 and 10 m. Muck can be segregated by resueing into mineralized material and waste, each to be handled differently based on logistical conditions at the time the material is generated. C&F accounts for 69 (17%) of the LOM stopes and yield 0.3 million (7%) of total tonnes.

The mining sequence begins by driving an attack ramp either from a level or from a nearby ramp. The attack ramp is driven at a 15% gradient to access the bottom (sill) cut of the mineralized zone near the centre of the stope mass using the same development equipment as used for ramp and level development. The mineralized zone is developed with sill drifts to the extents of the mineralization. A sill mat is installed, if required, prior to backfilling with paste fill, or rock fill if available from the nearby development headings.

When C&F stoping is to be conducted in weaker ultramafic talc, planners have employed a method that minimizes open spans. The C&F process is detailed as follows:
- Drift 4 m x 4 m along strike;
- Use standard Swellex support plus shotcrete walls and back (50 mm to 150 mm thickness);
- Cut 4 m x 4 m rooms between 4 m wide ribs;
- Continue rooms to stope width and complete mining of cut;
- Barricade and paste fill.

Alimak Mass Blasting Raise Mining
MBRM is a well-suited method for recovery of vein structured orebodies down to 1 m in thickness. It has strong economic and production considerations for extracting narrow mineralized seams without requiring access to a top sill. MBRM is used in 52 of the 403 stopes generating 0.5 Mt planned in this study.

Comminution

Crushers and Mills

TypeModelSizePowerQuantity
Roll crusher MMD 625 1
SAG mill 6.1m x 3.35m 1
Ball mill 3.2m x 4.9m 1

Summary:

Ore Crushing and Storage

Existing Circuit
The original conception for the Project (SRK, 2013b) installed an underground grizzly screen on the 305 m Level with standard 23 cm openings (10" x 10") and a rock breaker to reduce the ore size prior to hoisting to the surface. Underground crushing was included in the initial design and a 48" jaw crusher, associated hoppers, structural steel, and electrical equipment were procured but never installed. Skipped ore was to be dumped into a 277-tonne capacity raw-ore bin adjacent to the headframe, while the waste was to be dumped into the waste bunker adjacent to the headframe. Ore was to be discharged from the raw-ore bin via a discharge chute onto a vibratory feeder, which would transfer ore in a controlled fashion onto the ore storage bin feed conveyor. A cross-belt magnet situated above, and running perpendicular to, the ore storage bin feed conveyor would be used to remove tramp metal from the ore as it was conveyed to the ore storage bin.

Initial 2015 operations used the mill reclaim system to feed ore into the Mill, then in September 2015 the full ore handling system was commissioned, less the underground crusher. The lack of crushing in 2015 presented some challenges for SAG mill operations, as out of specification (coarse) ore was fed into the circuit. For the 2018 operations, the ore handling system was not recommissioned since the bulk sampling process required that ore be stockpiled on surface separately by stope. Again, the reclaim system was used to feed the SAG mill and again some SAG mill control challenges were experienced. These historical operations have demonstrated that the SAG mill has capability to process -10" material, but that uncrushed ROM (typically sized at - 18") would not be possible.

The Feasibility Study mine production plan includes uncrushed ROM ore haulage to surface for 18 months while a new ROM sizing station is installed at the 610 m Level (rock breaker/grizzly). Thereafter, all mine production would be sized to -10" before being hoisted to surface. The Feasibility Study also includes the installation of a new SAG mill feed sampling system, which requires a 6 maximum topsize. A new surface crushing facility is therefore essential for smooth operation and good mine-mill metal reconciliation.

Surface Crushing Facility Project
A new surface crushing facility will be installed prior to mill start up.

Technical and commercial adjudications resulted in the selection of a loader-fed crushing option, located next to the existing raw-ore bin. The selected crusher is an MMD 625 double-tooth roll crusher, specified to treat 250 t/h of -24" feed. The crusher is sized for durability and is currently used in applications crushing felsic intrusives at uniaxial compressive strengths ranging from 120 to 320 mPa. The advantages of this particular crusher include its low profile, its ability to accept all feed (i.e., no grizzly required to bypass fines) and its ability to run with little to no bed covering the rolls. The crushed product from this unit is consistently cubical (compared to jaw crushers which produce more elongated particles) and ranges from -4" to -6".

The selected ore crushing circuit includes a 10-tonne capacity feed hopper with a 4 ft wide inclined apron feeder to transfer ore into the mouth of the roll crusher, where it is sized to 100% -6". Crushed product gravitates on to a short transfer conveyor that feeds onto a vertical conveyor. The vertical conveyor transfers crushed ore onto the existing inclined conveyor feeding the ore storage bin. A cross-belt magnet will be installed on the short transfer conveyor where metallic scrap can be removed after crushing. Dust collection for the outdoor crusher system consists of plenum enclosures and collection points over the feeder, crusher, transfer conveyor, and vertical-pocket conveyor transfer points, and collected dust is returned to the transfer conveyor.

Grinding
ROM ore from the ore storage bin is reclaimed by two apron feeders and is discharged onto a first conveyor. The material on the first conveyor is discharged to a second, high-angle conveyor equipped with a belt scale, which then transfers the mineralized material to the SAG mill mobile feed chute. Ore reclaimed from stockpiles can be fed through a hopper, feeder belt, and transfer conveyor to the SAG feed conveyor, bypassing the ore storage bin.

The grinding circuit consists of a 6.1 m x 3.35 m SAG mill and a 3.2 m x 4.9 m ball mill. The SAG mill operates in open circuit, while the ball mill is operated in closed circuit with 380 mm hydrocyclones. Process water is added to the SAG mill feed chute to achieve the correct density for grinding. The mill head grade is measured by passing the SAG mill discharge slurry through a two-stage sampling system that includes an interstage ball mill for sample size reduction. The sampler discharges slurry into the ball mill discharge tank, from which it is pumped to the cyclone cluster. Approximately 75% of the cyclone underflow is directed to the ball mill for regrinding, while the remaining portion gravitates to the gravity separation circuit. The cyclone overflow pulp flows to the pre-leach thicker circuit.

The pre-leach thickener is protected from tramp material by a trash screen on the feed stream. This screen is gravity-fed from the cyclone cluster via primary and secondary slurry samplers. The screen undersize flows by gravity to the pre-leach thickener feed box. Any oversize trash is dewatered and dumped into a trash bin.

The pre-leach thickener is fed by the trash screen undersize and the thickening area sump pump. Flocculant is also added to improve the settling rate and lime is added to adjust pH. The thickener overflow feeds by gravity to the process water tank, while the underflow is pumped to the pre- aeration tank in the CIL circuit. During shutdown, the thickener underflow recirculates to the thickener feed box.

Processing

  • Gravity separation
  • Shaker table
  • Calcining
  • Smelting
  • Carbon re-activation kiln
  • Centrifugal concentrator
  • Agitated tank (VAT) leaching
  • Magnetic separation
  • Carbon in leach (CIL)
  • Elution
  • Solvent Extraction & Electrowinning
  • Cyanide (reagent)

Summary:

The new Bateman Mill (currently on care and maintenance) has a nameplate capacity of 600ktpa and is currently permitted to 450ktpa. It may be expanded to 900ktpa with minimal expenditure. Evolution is working on expanding to 800ktpa but needs CAPEX and permitting.

The capacity of the Mill is 1,250 t/d. This section describes the Mill in its configuration, together with the capital projects identified in the Feasibility Study for reliable and efficient operation, and to allow the Mill to operate up to its design capacity of 1,800 t/d.

The existing process receives ore from the adjacent underground mine. Ore is either hauled by truck or hoisted to surface and following crushing, cleaned of metal scrap as it is conveyed to the ore storage bin. The ore is reclaimed from the ore storage bin and conveyed to the SAG mill. The discharge from the SAG mill is pumped to the ball mill which is configured in closed circuit via hydrocyclones. A gravity separation circuit is included within the circulating load to recover and concentrate gravity-recoverable gold present in the ore. The remaining gold is extracted in a conventional CIL circuit. Loaded carbon is removed from the CIL circuit using screens and is then washed with dilute hydrochloric acid solution to remove carbonate scale. Gold is then stripped from the loaded carbon in batches using a pressure Zadra elution process. Stripped carbon is forwarded to a reactivation kiln before being recycled into CIL, whilst the pregnant solution is pumped to a gold electrowinning circuit. The electrowinning and gravity circuits both produce high-grade gold concentrates that are smelted together in an electric induction furnace to produce dorÈ. Carbon fines are constantly recovered from the process to avoid gold loss, with fresh make-up carbon being continuously added to the process.

The cyanide contained in the CIL circuit tailing slurry is effectively eliminated in a cyanide destruction tank using the SO2/O2 cyanide destruction process. Either liquid SO2 or SMBS can be used as the source of SO2. Once the cyanide is destroyed, the tailing slurry is pumped to the TMF for storage. The Cyanide destruction process and mining both generate ammonia and cyanates as by-products so water must be treated to reduce these contaminants along with dissolved metals and fine suspended solids, to below regulated levels prior to discharge to the environment.

The Mill includes facilities designed to prepare paste backfill for the underground mining operation. When backfill is required by the mining operation, tailing slurry can be diverted to the paste plant where it is filtered to reduce the water content. Cake produced by the tailing filters is then mixed with fly ash and cement in a pre-determined ratio to produce a thick cement paste, which is pumped to the underground for backfilling.

The gold recovery plant, cyanide destruction process, and TMF were commissioned and operational in 2015. The backfill plant has not yet been commissioned, as the Project has not yet required backfill.

Recoveries & Grades:

CommodityParameterAvg. LOM
Gold Recovery Rate, % 95
Gold Head Grade, g/t 5.54

Production

CommodityUnitsAvg. AnnualLOM
All production numbers are expressed as payable metal.

Operational metrics

Metrics
Daily processing rate 1,208 t *
Daily processing capacity 1,800 t *
Annual processing rate 0.47 Mt *
Ore tonnes mined, LOM 3,562,572 t *
Tonnes processed, LOM 3,562,572 t *
* According to 2020 study.

Production Costs

CommodityUnitsAverage
All-in sustaining costs (AISC) Gold USD 865 / oz *  
C1 cash costs Gold USD 613 / oz *  
All-in costs Gold USD 1,010 / oz *  
Assumed price Gold USD 1,525 / oz *  
* According to 2020 study / presentation.

Operating Costs

Currency2020
UG mining costs ($/t mined) CAD 94.6 *  
Processing costs ($/t milled) CAD 34.8 *  
G&A ($/t milled) CAD 6.8 *  
Total operating costs ($/t milled) CAD 136.13 *  
* According to 2020 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M CAD 109.3
Sustaining CapEx $M CAD 188.8
Closure costs $M CAD 7.7
Total CapEx $M CAD 298.1
UG OpEx $M CAD 336.9
Processing OpEx $M CAD 123.9
G&A costs $M CAD 24.2
Total OpEx $M CAD 485
Royalty payments $M CAD 38.9
Gross revenue (LOM) $M CAD 1,240
Net revenue (LOM) $M CAD 1,202
Pre-tax Cash Flow (LOM) $M CAD 418.5
After-tax Cash Flow (LOM) $M CAD 418.5
Pre-tax NPV @ 5% $M CAD 305
After-tax NPV @ 5% $M CAD 305
Pre-tax IRR, % 50.2
After-tax IRR, % 50.2
After-tax payback period, years 3.6

Heavy Mobile Equipment

Ref. Date: September 7, 2020

SourceSource
HME TypeSizeQuantityLeased or
Contractor
Alimak climber 3 Leased
ANFO Loader 4 Leased
Deck & Boom Trucks 2 Leased
Drill 4 inch 1 Leased
Drill jumbo (single boom) 3 Leased
Drill jumbo (two boom) 4 Leased
Grader 1 Leased
Loader (FEL) 8 cu. yd 2 Leased
Load-Haul-Dump (LHD) 6 cu. yd 2 Leased
Load-Haul-Dump (LHD) 4 cu. yd 4 Leased
Load-Haul-Dump (LHD) 2.5 cu. yd 4 Leased
Personnel Carrier 6 Leased
Rock bolter 4 Leased
Scissor Lift 5 Leased
Shotcreter 3 Leased
Truck (boom) 2 Leased
Truck (fuel / lube) 1 Leased
Truck (haul) 30 t 1 Leased
Truck (haul) 50 t 3 Leased

Personnel

Mine Management

Job TitleNamePhoneProfileRef. Date
Chief Operating Officer Matt O'Neill LinkedIn May 2, 2024
Consultant - Mining & Costs Andrew MacKenzie LinkedIn Sep 7, 2020
Consultant - Recovery Methods Andy Holloway LinkedIn Sep 7, 2020
Environmental Superintendent Chris Gaspar LinkedIn Dec 30, 2023
General Manager Operations Thomas Lethbridge +1-807-735-2077 LinkedIn Dec 30, 2023

Total WorkforceYear
273 2020

Aerial view:

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