Overview

Deposit type

• Porphyry
• Intrusion related

Summary:

The Canadian Malartic property straddles the southern margin of the eastern portion of the Abitibi Subprovince, an Archean greenstone belt situated in the southeastern part of the Superior Province of the Canadian Shield. The Abitibi Subprovince is limited to the north by gneisses and plutons of the Opatica Subprovince, and to the south by metasediments and intrusive rocks of the Pontiac Subprovince. The contact between the Pontiac Subprovince and the rocks of the Abitibi greenstone belt is characterized by a major fault corridor, the east-west trending Larder Lake – Cadillac Fault Zone (“LLCFZ”). This structure runs from Larder Lake, Ontario through Rouyn-Noranda, Cadillac, Malartic, Val-d’Or and Louvicourt, Québec, at which point it is truncated by the Grenville Front.

The regional stratigraphy of the southeastern Abitibi area is divided into groups of alternating volcanic and sedimentary rocks, generally oriented at N280 – N330 and separated by fault zones. The main lithostratigraphic divisions in this region are, from south to north, the Pontiac Group of the Pontiac Subprovince and the Piché, Cadillac, Blake River, Kewagama and Malartic groups of the Abitibi Subprovince. The various lithological groups within the Abitibi Subprovince are metamorphosed to greenschist facies. Metamorphic grade increases toward the southern limit of the Abitibi belt, where rocks of the Piché Group and the northern part of the Pontiac Group have been metamorphosed to upper greenschist facies.

The majority of the Canadian Malartic property is underlain by metasedimentary units of the Pontiac Group, lying immediately south of the LLCFZ. The north-central portion of the property covers an approximately 16 kilometre section of the LLCFZ corridor and is underlain by mafic-ultramafic metavolcanic rocks of the Piché Group cut by intermediate porphyritic and mafic intrusions. The Cadillac Group covers the northern part of the property (north of the LLCFZ). It consists of greywacke containing lenses of conglomerate.

Mineralization
Mineralization in the Canadian Malartic deposit occurs as a continuous shell of 1% to 5% disseminated pyrite associated with fine native gold and traces of chalcopyrite, sphalerite and tellurides. It extends on a 2 kilometre strike and a width of 1 kilometre (perpendicular to the strike), and from surface to 400 metres below surface. The gold resource is mostly hosted by altered clastic sedimentary rocks of the Pontiac Group (70%) overlying an epizonal dioritic porphyry intrusion.

Surface drilling by Lac Minerals Ltd. in the 1980s defined several near-surface mineralized zones now included in the Canadian Malartic deposit (the F, P, A, Wolfe and Gilbert zones), that are all expressions of a larger, continuous mineralized system located at depth around the historical underground workings of the Canadian Malartic and Sladen mines. In addition to these, the Western Porphyry Zone occurs one kilometre northwest of the main Canadian Malartic deposit and the Gouldie mineralized zone occurs approximately 1.2 kilometres southeast of the main Canadian Malartic deposit.

The South Barnat deposit is located to the north and south of the old South Barnat and East Malartic mine workings, largely along the southern edge of the LLCFZ. The deposit that is originally modelled for surface mining evaluation extends on a 1.7 kilometre strike and a width of 900 metres (perpendicular to the strike), and from surface to 480 metres below surface. The disseminated/stockwork gold mineralization at South Barnat is hosted both in potassic altered, silicified greywackes of the Pontiac Group (south of the fault contact) and in potassic altered porphyry dikes and schistose, carbonatized and biotitic ultramafic volcanic rocks (north of the fault contact).

The East Malartic deposit (as modelled for the underground mining model) has been previously mined by the East Malartic, Barnat and Sladen mines along the contact between the LLCFZ and the Pontiac Group sedimentary rocks. This deposit includes the deeper portion of the South Barnat deposit (below actual pit design). This deposit extends on a 3 kilometre strike and a width of 1.1 kilometres (perpendicular to the strike), and from the bottom of the South Barnat current pit design to approximately 1,800 metres below surface. The geological settings are similar to those found in other areas of the property, corresponding mainly to the depth extension of the geological context presented above for the South Barnat open pit deposit.

The Odyssey deposit is also located at the contact between the LLCFZ and the Pontiac Group sedimentary rocks in the eastern extension of the East Malartic deposit. It extends on a 2 kilometre strike and a width of 500 metres (perpendicular to the strike), and from surface to approximately 1,500 metres below surface. It is characterized by the presence of a massive porphyritic unit. While the whole porphyritic intrusion is anomalous in gold, continuous zones of higher-grade (>1 g/t gold) gold mineralization occur along the south-dipping sheared margins of the intrusion (in contact with the Pontiac Group to the south and the Piché Group to the north). Within the porphyritic unit, gold mineralization is also associated with other geological features, including silica and potassic alteration zones, discrete shear zones, swarms of quartz veins, stockworks and zones with disseminated pyrite (0.5 to 2.0%).

The East Gouldie deposit is located south of the Odyssey deposit and has a strike length of at least 2.1 kilometres and extends from approximately 780 metres below surface to more than 1.9 kilometres depth. It’s generally constrained in a west-trending high-strain corridor (40 to 100 metres true width) that dips approximately 60 degrees north. The high strain corridor is defined by a strongly developed foliation that affects Pontiac Group greywacke as well as crosscutting east-southeast-trending intermediate porphyritic dikes and mafic dikes. Evidence for folds in bedding occur in historical surface geology maps and in drill core, but the deposit is tabular and relatively straight. The mineralization is hosted in highly strained intervals of greywacke with 1% to 2% disseminated pyrite and strong silica alteration, and moderate sericite and carbonate alteration. Intermediate porphyritic dikes locally occur in the mineralized zones and are gold-bearing where affected by the high strain and alteration. Minor irregular cm-to dm-scale quartz veins occur, some with visible gold, but the bulk of the gold mineralization is interpreted to be associated with the disseminated style of mineralization.

Several other mineralized zones have been documented within the LLCFZ, namely Malartic Goldfields, North Barnat, East Amphi, Western Porphyry and Fourax, all of which are generally spatially associated with stockworks and disseminations within or in the vicinity of dioritic or felsic porphyritic intrusions.

Mining Methods

• Truck & Shovel / Loader
• Sub-level open stoping (SLOS)
• Longitudinal retreat
• Transverse stoping

Summary:

The Canadian Malartic Complex is comprised of the Canadian Malartic open-pit mine and processing facility, and the Odyssey underground mine.

Canadian Malartic has historically been a large open-pit operation using large-scale excavators and trucks. The Canadian Malartic pit was depleted in 2023 and open pit operations continue at the Barnat pit. Mining at the Odyssey project will be done using underground methods. The mine design at the Odyssey project includes a 1,800 metre deep production-services shaft with an expected capacity of approximately 20,000 tonnes of ore per day once commissioned. During the second quarter of 2023, production using the ramp at the Odyssey South deposit commenced.

Mining at the Canadian Malartic mine is by open pit method with excavators and trucks, using large scale equipment. The primary loading tools are hydraulic excavators, with wheel loaders used as a secondary loading tool. The current mine production schedule was developed to feed the mill at a nominal rate of 52,000 tonnes per day. The continuity and consistency of the mineralization, coupled with tight definition drilling, that has been confirmed by many years of mining operations, demonstrate the amenability of the mineral reserves and mineral resources to the selected mining method.

Waste material is stored north of the TSF. An estimated total tonnage of 450 Mt of waste will be placed on the waste rock pile. An in-situ compacted density of 1.96 t/m3 was used to estimate the storage volume of 230 Mm3.

The ramps and haul roads are designed to accommodate the largest equipment, which is currently the Caterpillar 793F haul truck. For double-lane traffic, provincial regulations are followed. Double lane roads are designed for all accesses. Optimization to complete mining at the bottoms of pits is planned to be single lane. The travelling surface is at least triple the width of the largest vehicle. Ramp gradients are designed at 10%.

The open pit mine life is planned to extend to 2029, with mining continuing to transition from the Canadian Malartic pit to the Barnat pit. Production will transition from the open pit to the underground between 2023 to 2029. The Odyssey underground project supports a mine life to at least 2039 with annual gold production of 500,000 to 600,000 ounces when fully ramped up on a 100% basis. Opportunities exist for supplemental production sources to increase throughput beyond the 20,000 tpd as outlined in the Technical Study (as defined herein) and utilize the excess process capacity of the 60,000 tpd Canadian Malartic plant. Exploration drilling of the East Gouldie Extension and parallel structures, while widely spaced, indicate that a corridor of mineralization extends at least 1.3 kilometres to the east of East Gouldie. Although at the very early stages, these results suggest the potential for a second production shaft that could increase throughput over the longer term. Open pit and underground exploration targets within the Canadian Malartic land package present additional potential ore sources.

Mining at the Odyssey mine will be done using underground methods. The mine design at the Odyssey mine includes a 1,800 metre deep production services shaft with an expected capacity of approximately 20,000 tonnes per day. Mining activities are expected to primarily use a sublevel open stoping mining method with paste backfill. Longitudinal retreat and transverse primary-secondary mining methods will also be used depending on mineralization geometry and stope design criteria. Mining at Odyssey is expected to use a combination of conventional and automated equipment, similar to what is currently used at the LaRonde Complex. Production using the ramp commenced in March 2023, and is expected to be sustained at 3,500 tonnes per day throughout 2024. The shaft will have a depth of approximately 1,800 metres and the first loading station is expected to be commissioned in 2027 with modest production from East Gouldie. The Odyssey North and East Malartic shallow area and Odyssey North are scheduled to enter into production in 2028 and 2030, respectively.

The Odyssey mine benefits from the utilization of existing infrastructure at the Canadian Malartic complex, which includes the processing plant, the tailing storage facilities and the maintenance facilities. Additional infrastructure is being developed to support production using a ramp from surface for the shallow mineralized zones and using a 1,800 metre deep production shaft for the deeper mineralized zones below 600 metres. Shaft sinking activities started in March 2023. The Company expects to complete and commission the production shaft in 2027.

The production shaft will be 1,800 metres deep and 6.5 metres in diameter. It will be a concrete-lined circular shaft equipped with a steel set and divided into four compartments. The shaft is designed to allow the operation of two 52-tonne skips for a daily capacity of 20,000 tpd.

Shaft sinking is now anticipated to be completed in the first half of 2027 and the Company is assessing opportunities to accelerate it. With ramp development performance betterthan-expected, the Company is evaluating the option to pre-sink two legs of the shaft from levels 26 to 36 and levels 54 to 62, which could reduce the overall timeline by up to two months.

The service hoist is expected to be operational to a temporary loading station at Level 102 (1,050 metres below surface) by late 2025 and will support the transportation of people, materials and waste. The main production hoist, ore silo and the loading station at Level 114 are expected to be completed and commissioned in mid-2027. The second loading station and material handling system at Level 166 (shaft bottom) are expected to be finalized in 2029.

Production from East Gouldie is now expected to start in the first half of 2027 via ramp. The first loading station of the production shaft at Level 114 is expected to be completed and commissioned in mid-2027. Production from East Gouldie will then be hauled to surface via shaft and is expected to ramp-up through 2028 to reach a run-rate of approximately 12,500 tpd. The larger mineral resource base at East Gouldie resulted in the extension of planned production from this zone to 2042.

Production from Odyssey North is now expected to start in 2028 and ramp up to a run rate of approximately 3,500 tpd by 2030. Full production is expected to be maintained from this zone until 2038.

Production from East Malartic is now scheduled to start in 2030 and progressively increase to a run rate of approximately 3,200 tpd. Production from East Malartic has also been extended to 2042 and has the potential to be further extended alongside any East Gouldie mine life extension.

The construction of the paste plant will be completed in two phases. The first phase is expected to achieve a backfilling capacity of approximately 4,000 tpd to support production activities from Odyssey South. The construction of the first phase of the paste plant was completed in the second quarter of 2023.

Comminution

Crushers and Mills

Summary:

Crushing circuit
Run of mine (“ROM”) ore is transported to the gyratory crusher. Material from the primary crusher is conveyed to a secondary crushing plant. The crushed ore feeds a conveyor to transport the ore to the covered stockpile. The ore is reclaimed from the stockpile in an underground reclaim tunnel and is conveyed to the primary grinding SAG mill in the concentrator.

Grinding circuit
The SAG mill is in a closed circuit with scalping screens and two pebble crushers. The SAG circuit product is fed to the secondary grinding ball mills, which feed the tertiary grinding ball mill to produce a final product size suitable for feeding the leach circuit. There are two secondary ball mills and each one is a closed circuit with one cluster of hydrocyclones, while the tertiary grinding ball mill requires two clusters of hydrocyclones.

The slurry is brought to a pH of approximately 11 with lime added at the SAG mill feed step. The ground slurry passes through linear screens, before the thickener, to screen out any organic material and any other tramp material that has come into the mill with the ore, which would otherwise be kept in the carbon in pulp (“CIP”) circuit by the carbon screens.

Processing

• Electric furnace
• Crush & Screen plant
• Smelting
• Sulfuric acid (reagent)
• Carbon re-activation kiln
• Agitated tank (VAT) leaching
• Carbon in pulp (CIP)
• Elution
• Carbon adsorption-desorption-recovery (ADR)
• Solvent Extraction & Electrowinning
• Cyanide (reagent)

Summary:

The processing plant has a nominal capacity of 60,000 tonnes of ore per day.

Ore is processed through conventional cyanidation. Ore blasted from the pit is first crushed by a gyratory crusher followed by secondary crushing prior to grinding. Ground ore feeds successively into leach and CIP circuits. A Zadra elution circuit is used to extract the gold from the loaded carbon. Pregnant solution is processed using electrowinning and the resulting precipitate is smelted into gold/silver dore bars. Mill tails are thickened and detoxified using a Caro acid process, reducing cyanide levels below 20 parts per million. Detoxified slurry is subsequently pumped to a conventional tailings facility. The end of life of the tailings storage facility is estimated to be mid-year 2024 with the addition of the PR7 cell. From then onwards, the tailings are expected to be pumped into the Canadian Malartic pit.

PLANT
The slurry is thickened to an average of 53% solids in the pre-leach thickener before being fed to the leach circuit. The leach tanks are located outside and consist of four series of five tanks in parallel with agitators. Oxygen is added to raise the oxygen level in the solution phase in order to maintain the leach kinetics. From the leach tanks, the slurry flows by gravity to the CIP circuit. The circuit is composed of two parallel sets of Kemix CIP pump cell carousel systems. Each cell contains approximately 13 t of carbon. The loaded carbon and slurry are pumped from the cell in the first stage of the carousel circuit to a loaded carbon screen where the carbon is separated from the slurry. The slurry returns to the second stage cell of the carousel while the loaded carbon is transferred to the stripping vessels by gravity.

The Split-Zadra process is used to extract the gold from the loaded carbon. The caustic solution is heated to about 140°C and is then passed through the pressurized stripping vessel that strips the gold from the loaded carbon and sends it into the stripping solution. The solution is sent to the electrowinning circuit where gold is plated onto stainless steel wool cathodes. The plated gold is pressure washed from the cathodes and then filtered, dried and sent to a refining furnace where the gold is poured into doré bars. The bars contain a significant amount of silver that is recovered along with gold.

The stripped carbon is transferred to the carbon reactivation kilns, where it is reactivated by heating it to about 800°C in a reducing atmosphere. The carbon is then re-used in the CIP circuit. Fresh carbon is regularly added to make up for attrition losses. The activated carbon is pumped to the tank in the CIP that has been emptied when the loaded carbon has been removed to start a new tank in the carousel. Before being added to the last tank in the carousel series, the carbon is screen do ensure that no fine particles of carbon are introduced into the circuit.

The slurry flowing from the last tank in the carousel series is barren of gold and is considered as tailings. This slurry is discharged over linear safety screens as insurance against coarse carbon losses from the circuit. The slurry is thickened to approximately 63% solid in the tailing thickener. The thickened tailings slurry is pumped to the detoxification plant where the total cyanide content is reduced to less than 20 ppm using Caro’s acid. The detoxified slurry is subsequently pumped to the tailings retention ponds, where most of the water drains out to be reclaimed back into the process.

Water Supply

Summary:

The mine is connected to the sewage and potable water systems of the town of Malartic. The sewage is collected at the mine site and pumped through a 200 mm diameter HDPE buried line, connected to the municipal grid located in the industrial park. The 150 mm potable water line is also buried and follows the same route as the sewage line.

Three distinct water systems are used at the Canadian Malartic mine’s processing plant. Process water comes from the pre-leach and tailing thickeners overflows and is mainly recycled at the grinding circuit. Reclaim water comes from the Southeast pond and is used if there is insufficient process water in the circuit. Lastly, fresh water, which can notably be used for process water, reagent preparation water and gland seal water, is pumped from the Johnson pond located south of the mill.

A water treatment plant has been built to treat water pumped from the Southeast Pond before discharging it into the polishing pond for a capacity of 1,000 m3 /hour. The effluent treatment plant (“ETP”) is used mainly for cyanide destruction, dissolved metal ions and total suspended solids removal. It is a common oxidation process (hydrogen peroxide and copper sulphate) followed by the addition of a metal precipitant, addition of iron sulphate as a coagulant and the addition of a flocculant. The discharge of the ETP is then filtered by geotubes located at the polishing pond prior to final discharge to the environment. Treatment occurs mainly in the spring when ice melting raises the pond’s levels or during the summer.

Production

Operational metrics

Personnel

Job Title	Name	Profile	Ref. Date
Engineering Superintendent	Mathieu Labarre		Apr 2, 2024
General Director	Christian Roy		Apr 2, 2024
General Manager	Patrick Mercier		Apr 2, 2024
Mill Manager	Jean Chateauneuf		Apr 2, 2024
Mine Engineering Superintendent	Pierre-Olivier Richard		Apr 2, 2024
Mine Maintenance Superintendent	Serge Arseneault		Apr 2, 2024
Mine Technical Services Manager	Patrick Fiset		Apr 2, 2024