The Canadian Malartic Complex is one of the world’s largest gold mining operations and is comprised of the open-pit Canadian Malartic mine and the underground Odyssey mine. The open-pit mine and 60,000-tpd-capacity processing plant produced 658,792 ounces of gold in 2022 (100% basis). Open pit mine life is expected to last through 2029, and the ongoing ramping up of the new underground Odyssey mine will extend the overall life of the complex to 2039.
Proven and probable mineral reserves for the complex totalled 3.21 million ounces of gold (107 million tonnes at 0.93 g/t gold) on a 100% basis, as at December 31, 2022. The Odyssey mine project had probable mineral reserves of 196,000 ounces of gold (3.8 million tonnes grading 2.22 g/t gold), indicated mineral resources of 6.2 million ounces of gold (64.2 million tonnes grading 2.99 g/t gold) and inferred mineral resources of 9.2 million ounces of gold (132.4 million tonnes grading 2.17 g/t gold) on a 100% basis as at December 31, 2022.
In February 2021 following the completion of an internal technical study, the Partnership approved construction directly to the east of the Canadian Malartic/Barnat pit of the Odyssey mine project — an underground mining operation that will exploit three main deposits: East Gouldie, East Malartic and Odyssey. Average annual payable production from the Odyssey mine is expected to be approximately 545,400 ounces of gold from 2029 to 2039, with total cash costs per ounce of approximately $630. Sustaining capital expenditures are expected to gradually decline from 2029 to 2039, with an expected average of approximately $56 million per year.
In 2023, production is expected to be sourced from the Canadian Malartic pit, the Barnat pit and the Odyssey mine, complemented by ore from the low grade stockpiles. Mining in the Canadian Malartic pit is expected to be completed late in the first half of 2023 and will continue in the Barnat pit. The Odyssey mine is forecast to gradually ramp-up production in 2023, starting in March. The Odyssey mine is expected to contribute approximately 50,000 ounces of gold in 2023 and 80,000 ounces of gold in 2024 and 2025 to payable production at the Canadian Malartic Complex. The mill throughput at the complex is forecast to remain at approximately 51,500 tpd (100% basis) in 2023. With the depletion of the Canadian Malartic pit in 2023 and the transition to in-pit tailings disposal in the second half of 2024, the Company is evaluating opportunities to further increase the mill throughput up to 60,000 tpd (on a 100% basis).
Based on current mineral reserves, production from the Canadian Malartic and Barnat open pits extends to 2029. Run-of-mine ore from the pit is expected to decrease starting in 2022, as the ore production from the underground starts gradually in 2023 to reach a rate of 3,500 tpd in 2024. The underground is expected to reach full production of approximately 19,000 tpd by 2031.
Geology
The property lies in the southern margin of the eastern portion of the Archean-age Abitibi volcanic belt, mainly within the Pontiac Group of metasedimentary rocks. The Canadian Malartic property, together with the adjacent Rand Malartic, Midway and Camflo properties, cover in excess of 25 km along the Cadillac-Larder Lake deformation zone. The properties are underlain to the north by the Cadillac Group, in the centre by the Piché Group and in the south by the Pontiac Group. The mineralized zones are mostly located in the northern part of the Pontiac Group and in the Piché Group in proximity to the Cadillac-Larder Lake deformation zone.
The geological settings of the Odyssey mine’s East Malartic and Odyssey deposits are similar to those found in the western portions of the property, with both deposits located at the contact of the Cadillac-Larder Lake deformation zone and the Pontiac Group sedimentary rocks, and having a near-vertical orientation. In contrast, the East Gouldie deposit is located approximately 700 metres south of the Odyssey deposit entirely within the Pontiac Group greywacke and dips approximately 60 degrees north.
Mineralization
The deposits that were mined by open pit at Canadian Malartic were part of a large-tonnage, low-grade Archean gold system, consisting of a widespread shell of disseminated gold-bearing pyrite mineralization hosted by porphyritic felsic to intermediate intrusions and altered metasediments. The system is open to the west and to the south at depth. Mineralization in the Barnat deposit is largely along the southern edge of the Cadillac fault zone. The Canadian Malartic and Barnat deposits contained the bulk of the previous mineral reserves at the Canadian Malartic mine and are part of one large pit.
At the Odyssey mine, gold mineralization in the East Malartic and Odyssey deposits is similar to the deposits in the western portion of the property. In contrast, gold mineralization in the East Gouldie deposit is higher grade and is hosted in highly strained intervals of greywacke with 1% to 2% disseminated pyrite and strong silica alteration, and moderate sericite and carbonate alteration.
Mining
The Canadian Malartic mine has been a large open-pit operation using large-scale excavators and trucks, on the southern edge of the Town of Malartic. Since start-up, mining activities have been mindful of the need to limit noise levels from the mining operations, with drilling and blasting activities designed to control blast-induced vibrations and noise pressure on the neighbouring townsite. A 135-metre-wide buffer zone (the “green wall”) was developed along the northern limit of the open pit to mitigate the impacts of mining activities on the residents of Malartic. This ridge has been planted with shrubs, trees and grasses, and further enhanced by the addition of a park alongside, a bike trail and sculptures.
Upon depletion of the Canadian Malartic pit, preparation work will be undertaken to prepare for in-pit tailings disposal, which is expected to start in the second half of 2024.
Mining at the new Odyssey mine is by underground methods. The mine design includes a 1,800 metre deep production-services shaft with an expected capacity of approximately 20,000 tonnes per day. Mining activities will primarily use a sublevel open stoping mining method with paste backfill. Longitudinal retreat and transverse primary-secondary mining methods will also be used dependent on mineralization geometry and stope design criteria. The mine will use a combination of conventional and automated equipment, similar to what is currently used at the LaRonde Complex.
The first production blast from the Odyssey underground mine occurred in March 2023, with gold production totaling 2,799 ounces mostly from development ore. Processing of production ore is expected to begin in the second quarter of 2023.
The emphasis in the first quarter of 2023 will be on installation of an underground escapeway in the underground mine and starting work on the installation of the underground paste backfill network to further facilitate the production ramp up. The startup of the paste plant remains on schedule and is expected to occur in the second quarter of 2023.
Structural steel installation for the headframe reached the seventh floor in the fourth quarter of 2022, with completion to the ninth and final floor expected in during first quarter of 2023. Shaft sinking activities are planned to begin at the end the first quarter of 2023.
Processing
Ore from the open-pit and underground operations is processed at the Canadian Malartic mineral processing complex, which has a 60,000-tonnes/day nominal throughput capacity. Ore is transported to a crushing circuit and the crushed ore is stockpiled in a covered pile, then conveyed to the semi-autogenous grinding circuit followed by three identical ball mills, each in closed circuit with hydro-cyclones. The slurry is thickened to about 50% solids before being fed to the leach tank circuit for conventional cyanidation followed by carbon-in-pulp processing technology. The product is doré bars containing gold and silver.
To reduce the environmental impact, tailings are thickened and detoxified prior to being pumped to a tailings impoundment facility. Excess water is mainly re-used in the plant or treated prior to being discharged to the receiving environment.
As planned, starting in February 2022, the mill throughput levels were reduced to approximately 51,500 tpd (on a 100% basis) in an effort to optimize the production profile and cash flows during the transition to processing ore from the Odyssey mine.
Exploration
The primary exploration target at Canadian Malartic from 2019 to the present has been the East Gouldie deposit, which was discovered in late 2018 at underground depths approximately 1.5 km east of the Canadian Malartic/Barnat open pit and south of the East Malartic and Odyssey underground deposits. The East Gouldie deposit has a strike length of 1,400 metres in an east-west direction, dips 60 degrees north, and extends from 700 metres to 1,900 metres depth below surface. The deposit is a silicified and carbonatized mineralized envelope with fine disseminated pyrite developed in sheared greywacke units.
Exploration drilling in 2022 at the Odyssey project focused on infilling the East Gouldie deposit from surface and the Odyssey South deposit from underground, as well as obtaining more information on the Odyssey internal zones. Exploration drilling also continued to investigate extensions of the East Gouldie Zone laterally to the east and to the west.
East Gouldie hosts indicated mineral resources of 5.3 million ounces of gold (50.2 million tonnes grading 3.29 g/t gold) and inferred mineral resources of 2.6 million ounces of gold (32.4 million tonnes grading 2.54 g/t gold) on a 100% basis as at December 31, 2022.
East Malartic was previously a gold-producing property, located directly adjacent to and east of the Canadian Malartic mine, and west of the Odyssey deposit. On a 100% basis, the East Malartic deposit has an indicated mineral resource of 770,000 ounces of gold (12.2 million tonnes grading 1.96 g/t gold) and an inferred mineral resource estimated at 5.0 million ounces of gold (77.6 million tonnes grading 2.01 g/t gold) to a depth of 1,800 metres, as at December 31, 2022.
The Odyssey deposit lies approximately 1.5 km east of the current limit of the Canadian Malartic open pit and is grouped into two elongated zones — Odyssey North and Odyssey South, approximately 500 metres apart — that strike east-southeast and dip steeply south. On a 100% basis, the probable mineral reserves at the Odyssey deposit are estimated at 196,000 ounces of gold (3.8 million tonnes grading 2.22 g/t gold), indicated mineral resources are estimated at 92,000 ounces of gold (1.8 million tonnes grading 1.59 g/t gold), and inferred mineral resources are estimated at 1.6 million ounces of gold (22.5 million tonnes grading 2.18 g/t gold) as at December 31, 2022.
The East Gouldie, East Malartic and Odyssey mineral resources do not form part of the Canadian Malartic mine’s mineral reserve and mineral resource estimate.
In March 2019, the Partnership acquired a 100% interest in the Rand Malartic property, which extends 1.7 km immediately eastward from the Odyssey project and provides an additional 262 hectares of prospective ground with the same favourable geological settings as the Odyssey and East Gouldie deposits. The East Gouldie eastern extension continues to be investigated up to the eastern boundary of the Canadian Malartic property and onto the adjacent Rand Malartic where the zone was intersected more than 1.2 km away from the current mineral resources limit.
At Canadian Malartic in 2023, the Company expects to spend a total of approximately $21.8 million (50% basis for the first quarter of 2023 and 100% basis for the remaining quarters of 2023) for 164,000 metres of drilling (100% basis). Exploration at the Odyssey project includes $11.8 million for 102,000 metres of drilling with four objectives: continued drilling into East Gouldie to convert additional inferred mineral resources to indicated mineral resources towards the outer portions of the deposit; testing the immediate extensions of East Gouldie to the west and at shallower depths; continued conversion drilling into extensions of the Odyssey South deposit; and further investigation of Odyssey's internal zones.
Another $5.0 million is budgeted for 40,000 metres of drilling into what the Company believes are highly prospective gold targets along the Barnat and East Gouldie corridors on the Canadian Malartic and Rand Malartic properties.
Camflo
Approximately $5.0 million is budgeted in 2023 for 22,000 metres of exploration drilling mainly to complete a first phase of drilling at the adjacent, past-producing Camflo property acquired by the Partnership in 2021 for its near-surface, bulk-tonnage gold mineralization potential.