Source:
p. 48

Argonaut's wholly owned (i.e., 100% Registered Ownership) land holdings forming the Magino property comprise 18 patented mining claims (mining and surface rights), 61 leased mining claims, and 14 unpatented mining claims with a combined area of 2,213 ha. Title to the property is wholly owned by Prodigy Gold Inc.
Deposit Type
- Vein / narrow vein
- Orogenic
- Breccia pipe / Stockwork
Summary:
The property is located within the Michipicoten greenstone belt of the Archean Superior Province. The Michipicoten greenstone belt is a structurally and stratigraphically complex assemblage of volcanic, sedimentary and intrusive rocks that were metamorphosed to greenschist and amphibolite facies. Several suites of plutonic rocks ranging in composition from gabbro to monzogranite and syenite occur in and around the Michipicoten greenstone belt. The property is situated in the Goudreau-Lochalsh gold district of the Wawa gold camp.
The Michipicoten Greenstone Belt area is part of the Wawa Sub-Province and hosts mainly precious metal deposits. Major breaks such as the Goudreau-Lochalsh Deformation Zone (GLDZ) host a number of gold deposits in the Wawa Sub-province.
There are two distinct styles of gold mineralization:
• Orogenic lode-gold greenstone hosted mesothermal gold;
• Intrusive-related ‘porphyry’ disseminated style.
Gold mineralization at Magino Project fits both the sub-volcanic ‘porphyry’ and orogenic style model. Gold associated with the ‘porphyry-style’ at Magino is characteristic of 1) Webb Lake/Lovell Lake Stock granodiorite-tonalite-trondhjemite (GTT) host, 2) widespread phyllic alteration with Nadepletion and K-enrichment, 3) weakly disseminated pyrite ± molybdenite mineralization, 4) weakly veined quartz stockwork network. The orogenic model at Magino involves steeply plunging intersecting lineation in high strain ductile/brittle structures and receptive chemical host traps.
Mineralization
Gold mineralization at the Magino gold mine occurs primarily within the Webb Lake granodiorite. The WLS underwent variable metasomatic alteration during deformation and gold mineralization (Heather and Arias, 1992). Distinct haloes of quartz-sericite with minor pyrite, iron-carbonate and hematite alteration are typically located adjacent to the quartz vein systems. In addition, narrow zones of mineralization have also been identified in metavolcanic rocks in both the footwall and hanging wall of the WLS.
Gold mineralization occurs in several sub-parallel high-strain zones striking 070º to 080º within the Webb Lake Stock and within mafic metavolcanic rocks immediately along the northern and southern margins of the stock (Heather and Arias, 1992). These zones are often closely related to mafic and felsic dykes within both units. Deevy (1992, 1994) distinguished and described two types of mineralized material shoots, namely “zones” and “veins”. The “zones” are usually 2 to 4.5 m wide and have a strike length of 25 to 70 m. They consist of foliated, bleached, and silicaflooded granodiorite. The zones are folded in places, which, during underground mining, produced mineable widths of up to 10.5 m. The zones dip at about the same angle as the foliation and have a vertical plunge. The vertical continuity of the zones is at a vertical to horizontal ratio of 2.5:1 (Deevy, 1994). Weak to moderate bleaching and silica flooding are the distinguishing features of the zones (Deevy, 1994). Silica flooding consists of incipient pale gray quartz occurring within the foliated granodiorite. Gold content is directly related to the amount of silica flooding and quartz veining (Deevy, 1994).
The veins consist of discrete pale grey to pale green to almost white quartz veins varying in width from a few to 45 cm. They have a strike length of several to 35 m. Gold values are distributed erratically within the veins, but overall grades can be quite high. The veins are folded in places, with gold sometimes concentrated in fold noses (Deevy, 1992, 1994). Vertical continuity of the veins is similar to that of the zones, and the plunge is also vertical. Native gold occurs in zones of pervasive silicification and in narrow (i.e., less than 1 to 20 cm wide) quartz veins that form complex systems 1 to 3 m wide. Gold occurs within both quartz veins and foliated and altered wall rocks, but the better gold grades are in the veins (T. Deevy, Magino mine geologist 2001, personal communication, as cited in Heather and Arias, 1992). Finely disseminated leaf-like visible gold can be observed in quartz veins exposed in diamond drill cores (Koskitalo, 1983). The gold tends to form plates or leaves along fractures in quartz rather than coarse nuggets. The quartz hosting the gold tends to be fine-grained and dull milky grey (Koskitalo, 1983). Up to 10% disseminated pyrite is locally present, commonly found in alteration haloes around the gold-bearing quartz veins (Heather and Arias, 1992).
Summary:
This Technical Report is based on a conventional open pit mine. Mine operations will consist of drilling small to medium diameter blast holes, ranging from 11.4 cm (4.5 in) to 20.3 cm (8.0 in) and blasting with explosive emulsions. Ore mining will be with two 7 cu m hydraulic excavators (backhoe configuration) to provide better selectivity and control of mining dilution. There will also be a 15 cu m hydraulic shovel for bulk mining of waste areas. A large wheel loader will also be available as a backup loading unit and also to rehandle ore stockpiled at the crusher. Most of the haulage will be with 140 mt class trucks. Ore will be delivered to the primary crusher north of the pit, and waste to the waste storage facility, the Mine Rock Management Facility (MRMF), west of the pit. A significant amount of the waste will also be used in the construction of the Tailings Management Facility (TMF), located west of the pit. There will also be a small low-grade stockpile facility to store marginally economic material for processing during the last few years of commercial pit operations.
A mine plan was developed to supply ore to a plant with the capacity to process 10,000 tpd (3,650 ktpy). The mine is scheduled to operate two 12-hour shifts per day for 365 days per year.
Mining operations commenced during the 1st quarter of 2021. The mining activity to date has been mining waste material from a borrow pit, north of the main mineral deposit, but within the final pit limits, to provide material to build roads, the TMF, and other site facilities.
In general, the overburden at the Magino site is characterized by a thin layer of topsoil, underlain by roughly 2 to 11 m of silty sand from glaciofluvial / glaciolacustrine deposits, underlain by a gravel and sand layer to gravel and silty sand from moraine deposits ranging in thickness from roughly 0.5 to 6 m, overlying the bedrock. The overburden soils are generally cohesionless (or with very low cohesion) and consequently, the main mechanism for failure of the overburden materials would likely be raveling or planar failure.
The stability of the overburden slopes would be reduced by increased pore pressures; therefore, it will be important to maintain adequate drainage. Overburden will be excavated using 2H: 1V (26.7°) slope for the north of the pit and 2.5H:1V (21.8°) configuration for the rest of the pit perimeter. It will also be important to take measures as necessary to prevent potential erosion or seepage on the exposed face.
A minimum 10 m wide catch berm will be constructed at the overburden – bedrock contact in areas in front of lakes and where the overburden thickness is greater than 10 m. In all other areas, an 8 m wide catch berm will be applied.
Drainage ditches will be installed along the outside perimeter of the pit (where required) in order to collect and convey surface water away from the pit slopes.
Two structural domains (south wall, and the combined center and north walls) were identified, and the pit was divided into six design sectors for kinematic assessment. Inter-ramp slope angles are generally specified as 54o or 56o depending on the area of the pit.
The design includes 18 m wide geotechnical safety berms every 140 m vertical intervals of uninterrupted inter-ramp slopes and considers that the slopes will be excavated using controlled blasting techniques.
The production schedule is based on five mining phases (plus the borrow pit) that were designed by IMC during 2021. The mining phases have adequate working room for equipment. The road is 30 m wide at a maximum grade of 10%.
The schedule is based on an ore production rate of 10,000 tpd or 3,650 ktpy. Based on this production schedule, the commercial life of the project is just over 18 years, following the 2022 preproduction period.
Total waste in the mine production schedule amounts to 311.2 million tonnes. Overburden waste is about 10.0 million tonnes and will be placed in a small stockpile to the south of the TMF facility. About 45.2 million tonnes of mine waste will be used in construction of the TMF. This leaves 256.0 million tonnes for the main MRMF facility.
Flow Sheet:
Crusher / Mill Type | Model | Size | Power | Quantity |
Jaw crusher
|
.......................
|
|
225 kW
|
1
|
Cone crusher
|
.......................
|
|
381 kW
|
1
|
SAG mill
|
.......................
|
26' x 14.5'
|
5 MW
|
1
|
Ball mill
|
.......................
|
20' x 29'
|
6.3 MW
|
1
|
Summary:
Primary and Secondary Crushing
The crushing circuit will reduce the pit ROM ore from a nominal top size of 1000 mm to a product size of k80 = 42 mm.
Haul trucks will bring feed material from the mining operations to the crushing plant. The material is dumped from the trucks into the 210 t capacity ROM bin. The ROM bin has the capacity to accommodate approximately 1.5 truck-loads of run of mine ore. Ore is withdrawn from the ROM bin by an apron feeder and passes over a vibrating grizzly before feeding the jaw crusher.
The vibrating grizzly and jaw crusher, an FLSmidth Single Toggle TST1400 jaw crusher with a 225 kW motor, has the capacity to process 631 t/h of material based on a 66% utilization factor. The jaw crusher discharge will be conveyed to the 1.8 m by 6.1 m secondary crusher scalping screen. The scalping screen is a double deck vibrating screen with 60 mm apertures on the top deck and 35 mm apertures on the bottom deck. The scalping screen is designed to remove 30% of the jaw crusher product to the undersize. Scalping screen undersize is collected on the stockpile feed conveyor.
Combined oversize from the secondary scalping screen is feed to the secondary crusher feed bin. The feed bin has a nominal retention time of 10 minutes. The feed bin is equipped with a variable speed belt feeder to feed the secondary crusher. The secondary crusher, a FLSmidth Raptor 500 cone crusher with a 381 kW motor, has the capacity to process 550 t/h of material based on a 66% utilization factor and 30% of the jaw crusher product removed to the scalping screen undersize. Cone crusher discharge is collected on the stockpile feed conveyor.
The crushing circuit includes the following key equipment:
• ROM bin with a static grizzly and rock breaker;
• Apron feeder;
• Vibrating grizzly;
• Jaw crusher;
• Scalping screen;
• Secondary crusher feed bin;
• Belt feeder;
• Cone crusher.
Grinding Circuit
The grinding circuit will reduce the size of the crushed ore to a final product size k80 = 75 µm. The grinding process is an SAB circuit designed to operate at a nominal throughput of 453 t/h. Water will be added to the SAG mill feed to maintain the slurry density at 70% solids. SAG mill product will pass over a trommel discharge screen with screen oversize conveyed back to the SAG mill feed conveyor. There is provision to add a pebble crusher in the future if required. Trommel screen undersize flows to the cyclone feed pump box.
The ball mill will operate in closed circuit with the classifying cyclones. Ball mill discharge flows into the cyclone feed pump box. The cyclone feed pump box in addition to the cyclonefeed pump has a dedicated pump which feeds the gravity circuit.
Cyclone overflow with a k80 = 75 µm, will be screened to remove trash (wood chips etc.) before gravitating to the pre-leach thickener.
A side stream of ball mill discharge is pumped to the 2.1 m x 4.8 m gravity feed scalping screen. The screen is is fitted with 2 mm x 13.5 mm slotted polyurethane panels. Scalping screen undersize is split to two FLS Knelson KC-QS40 centrifugal gravity concentrators. The gravity concentrators operate on a batch basis and concentrate will flow by gravity to the Intensive Leach Reactor (ILR) circuit. The ILR is a Consep Acacia Model CS3000. Scalping screen oversize and gravity tailings gravitate to the cyclone feed pump box.
Concentrate is collected in the gravity concentrate storage cone. Once a full batch has been collected, concentrate is discharged into the reaction vessel. The concentrate is deslimed and then leached with sodium cyanide, caustic and LeachAid™ at 40o C. ILR pregnant leach solution will be pumped from the reaction vessel feed tank to the ILR pregnant tank, located in the gold room.
The leached residue within the reaction vessel will be washed.
The SAG mill is 7.92 m (26 feet) in diameter and has an effective grinding length of 4.42 m (14.5 feet) with a 5 MW variable speed drive. The ball mill is 6.10 m (20 feet) in diameter and has an effective grinding length of 8.84 m (29 feet) with a 6.3 MW drive.
Steel balls (grinding media) will be added to the SAG and ball mills in order to maintain the grinding efficiency. A feed hopper and continuous media feeder is used to add 125 mm diameter balls to the SAG mill feed conveyor. A ball kibble is used to feed 50 mm and 38 mm diameter balls to the ball mill feed chute with the overhead crane.
The grinding circuit process control systems will manage the routine operation of the SAG and ball mills and associated classification circuit as well as providing protection against the SAG mill running empty or the SAG and ball mills being started with a ‘frozen’ charge.
Processing
- Gravity separation
- Centrifugal concentrator
- INCO sulfur dioxide/air process
- Filter press plant
- Carbon re-activation kiln
- Smelting
- Wet Screening
- Dewatering
- Intensive Cyanidation Reactor (ICR)
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- AARL elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The process plant flowsheet design utilizes primary and secondary crushing followed by a semiautogenous (SAG) mill and ball mill for grinding. The SAG mill discharge is classified with a trommel screen to return oversize to the SAG mill feed. Ball mill discharge is in closed circuit with cyclones for classification and a gravity circuit to remove coarse gold. Prior to the leaching and Carbon-in-Pulp (CIP) circuit, the ground product (cyclone overflow) will be thickened in a pre-leach thickener to reduce the slurry volume and reagent requirements. The thickener overflow will be recirculated to the process water tank for re-use as process water. The thickener underflow will be pumped to the leach circuit, be dosed with lime and cyanide, leached for 30 hours, and will then flow into the CIP circuit to recover dissolved gold and silver from the leached slurry.
Loaded carbon from the CIP circuit will be acid washed, followed by carbon stripping using an AARL elution circuit and ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Gold
|
Recovery Rate, %
| 91.8 |
Gold
|
Head Grade, g/t
| 1.15 |
Reserves at January 31, 2022:
The Mineral Reserves used a variable gold cutoff grade of between 0.38 g/t Au and 0.70 g/t Au, depending on mine sequencing.
The Mineral Resources are reported at a gold cutoff grade of 0.28 g/t.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
26,286 kt
|
Gold
|
1.24 g/t
|
1,044 koz
|
Probable
|
39,238 kt
|
Gold
|
1.1 g/t
|
1,383 koz
|
Proven & Probable
|
65,526 kt
|
Gold
|
1.15 g/t
|
2,427 koz
|
Measured
|
43,558 kt
|
Gold
|
0.98 g/t
|
1,367 koz
|
Indicated
|
88,849 kt
|
Gold
|
0.93 g/t
|
2,652 koz
|
Measured & Indicated
|
132,407 kt
|
Gold
|
0.94 g/t
|
4,019 koz
|
Inferred
|
20,919 kt
|
Gold
|
0.78 g/t
|
526 koz
|
Corporate Filings & Presentations:
- Subscription is required.
News:
News | Date |
Argonaut Gold Reaffirms Magino’s Estimated Cost to Completion and Announces US$250 Million Binding Debt Commitment and Proposed Equity Financing to Fully Finance the Magino Construction...
|
June 23, 2022
|
Wärtsilä’s increasing footprint in Canada shows with another mining company order from Argonaut Gold
|
March 16, 2022
|
Argonaut Gold Files Updated Magino Technical Report
|
March 3, 2022
|
Argonaut Gold Inc. – Announces C$45 Million Bought Deal Financing
|
February 14, 2022
|
Argonaut Gold Intersects 16.0 Metres at 6.1 g/t Gold and 7.0 Metres at 8.8 g/t Gold at Magino's Elbow Zone
|
November 16, 2021
|
Argonaut Gold Announces Quarterly Production of 58,777 Gold Equivalent Ounces, $39.6 Million of Cash Flow¹ and Provides Third Quarter 2021 Operating and Financial Results
|
November 15, 2021
|
Argonaut Gold Announces Record Quarterly Production of 59,704 Gold Equivalent Ounces...
|
May 4, 2021
|
Argonaut Gold Announces Major Milestone of Magino Closure Plan Filing
|
January 21, 2021
|
Argonaut Gold Intersects 10.0 Metres at 19.0 g/t Gold at Magino, Including 6.3 Metres at 30.2 g/t Gold in South Zone
|
January 20, 2021
|
Argonaut Gold Discovers Four New High-Grade Mineralized Gold Zones Below and to the West of the Planned Magino Open Pit
|
November 23, 2020
|
Argonaut Gold Approves Magino Project Construction, Receives Fixed Bid Pricing Proposal, Announces US$50 Million Bought Deal Financing of Senior Unsecured Convertible Debentures and Expansion...
|
October 14, 2020
|
Argonaut Gold Drills High-Grade Intercepts of 12.4 Metres at 10.6 g/t Gold, Including 2.0 Metres at 48.7 g/t Gold and 9.0 Metres at 13.4 g/t Gold, Including 2.0 Metres at 55.6 g/t Gold...
|
September 16, 2020
|
Argonaut Gold Drills High-Grade Intercept of 6.0 Metres at 8.31 g/t at Magino; Phase Two Magino Drill Program Shows Promising Continuity Between High-Grade Intercepts in the Elbow Zone...
|
July 28, 2020
|
Argonaut Gold Continues to Intersect High-Grade Gold Mineralization at the Magino Project Below the Planned Open Pit Reserves Defined in the Feasibility Study
|
March 3, 2020
|
Argonaut Gold Confirms High-Grade Geological Continuity at the Magino Project Below the Planned Pit
|
December 2, 2019
|
Argonaut Gold Announces Results of Magino Drilling Program and Increases Deep Drilling Exploration Program...
|
September 10, 2019
|
Magino Gold Project --Environmental Assessment Decision
|
January 24, 2019
|
Argonaut Gold Announces Feasibility Study Results for Magino Project; After-Tax NPV of US$288 Million
|
November 8, 2017
|
- Subscription is required.