The Meadowbank Complex refers to the processing facilities and infrastructure at the Meadowbank mine site combined with the mining and infrastructure at the Amaruq site. The 118,862-hectare Amaruq property is located approximately 50 km northwest of the Meadowbank mine site, with a 64-kilometre road between the two sites completed in August 2017 and widened for ore haulage in November 2018.
The Meadowbank mine camp can host more than 500 employees at a time. The Amaruq camp can host an additional 350 employees.
The Meadowbank gold mine achieved commercial production in March 2010 and produced its three millionth ounce of gold in 2018. The final year of production at the Meadowbank mine was 2019, with mining operations at the Complex gradually transitioning to Amaruq, which today provides the sole source of mill feed. The Company declared commercial production at the Whale Tail pit at Amaruq on September 30, 2019.
Discovered in 2013, Amaruq hosts the Whale Tail gold deposit as well as the V Zone (IVR Zone), Mammoth Zone and several other targets. At December 31, 2020, the Amaruq property was estimated to contain open pit proven and probable mineral reserves of 2.3 million ounces of gold (19.9 million tonnes grading 3.64 g/t), underground probable mineral reserves of 564,000 ounces of gold (3.3 million tonnes grading 5.29 g/t), as well as substantial open pit and underground indicated and inferred mineral resources.
The Amaruq mining operation uses the existing infrastructure at the Meadowbank mine, including mining equipment, mill, tailings facilities, camp and airstrip. Additional infrastructure has been built at the Amaruq site, including a truck shop/warehouse, fuel storage and a second camp facility. Amaruq ore is transported using long haul off-road type trucks to the mill at the Meadowbank facilities for processing.
The life of mine plan for the Whale Tail pit calls for the production of approximately 2.5 million ounces of gold between 2019 and 2026.
The V Zone pit began pre-stripping activities in the third quarter of 2020 and achieved commercial production on December 31, 2020.
In February 2021, the Board approved the construction of the Amaruq underground project and first gold production is expected in early 2022. The objective is to mine higher-grade underground portions of the deposit in conjunction with the open pits.
Geology
The Meadowbank and Amaruq properties are underlain by Archean-age volcanic and sedimentary rocks of the Woodburn Lake Group. This is within the Rae domain of the Western Churchill geological province of the Canadian Shield. These rocks were possibly deposited in a continental rift setting and consist of mafic to ultramafic volcanic rocks interlayered with carbon-rich sedimentary rocks. The rock sequence has since been intruded by granitoid rocks and lamprophyres, and has been affected by multiple phases of ductile deformation along with metamorphism to greenschist facies and locally to the upper greenschist facies.
Mineralization
Gold deposits at the Meadowbank property are found along two main structural features that cross the property: the 25-km-long Meadowbank Trend and the Pipedream Lake (Northeast) Trend. The Meadowbank Trend hosts the Goose, Portage and Vault deposits (all now mined out). The Goose and Portage deposits are hosted by magnetite-rich iron formation, while intermediate volcanic rocks host most of the mineralization at the Vault deposit farther north. Both the rock units and the gold deposits are tightly folded and structurally complex, sandwiched between granitic plutons. These shallow deposits lie within 7 km of each other. The PDF deposit (a fourth deposit) has been outlined on the Northeast gold trend. In all deposits, gold mineralization is commonly associated with intense quartz flooding, and the presence of sulphide minerals (pyrite and/or pyrrhotite).
At the Amaruq property, three significant zones of gold-bearing quartz-pyrrhotite-arsenopyrite veining/flooding within volcano-sedimentary rocks have been discovered: Whale Tail, V Zone (IVR) and Mammoth. The Whale Tail and V zones appear to be offset mineralized corridors striking east-northeast to northeast and dipping moderately to steeply southeast.
The Whale Tail deposit has been defined over at least 2.3 km of strike length and from surface to 915 m depth; it includes the Whale Tail ore shoot in the mineralized chert-iron formation sequence plunging shallowly east-to-northeast. Whale Tail remains open at depth and along strike.
Immediately north of Whale Tail, the V Zone consists of a series of parallel stacked mineralized structures, striking northeast and extending from near surface to as deep as 707 m below surface; the southeast dip of the structures is approximately 30 degrees near surface and steepens to 60 to 70 degrees at depth, where there are at least two sub-parallel structures. The V Zone ore shoot, defined in 2018, is a mineralized corridor 100 to 150 m wide, locally more than 300 m wide, plunging shallowly eastward, extending from approximately 350 m to more than 700 m depth.
The Whale Tail and V zone deposits come together at depth northeast of Whale Tail Lake.
Mining
Mining concluded at the Meadowbank site in 2019.
A conventional open-pit mining operation has been developed at the adjacent Whale Tail and V Zone deposits at the Amaruq site, with ore being transported using long haul off-road type trucks to the mill at the Meadowbank facilities for processing. Following construction of two associated water retention dikes, mining from the Whale Tail pit began in the first quarter of 2019 with commercial production declared at the Whale Tail pit on September 30, 2019 and commercial production was declared at the V Zone (IVR) pit on December 31, 2020.
The existing exploration portal and ramp that connects the Whale Tail and V Zone deposits will be used for development and production at the Amaruq underground project. As at December 31, 2020, the exploration ramp had reached a depth of approximately 340 metres below surface and in 2021 approximately 2,421 metres of underground development are planned.
Long-hole open stoping will be used for mining the Amaruq underground deposit and stopes will be backfilled using cemented rockfill. A traditional truck and scoop tram approach will be used for underground mucking and hauling. Once at surface, ore will be hauled by a long haul, off-road truck fleet to the mill at the Meadowbank facilities for processing.
The mining rate at Amaruq underground is expected to start at 1,500 tpd and then ramp-up to 2,300 tpd. Over the five-year mine life, the average mining rate is expected to be approximately 2,000 tpd. The mine plan includes a pre-production period with operational ramp-up from the second quarter of 2021 to the third quarter of 2022. Commercial production is expected in the fourth quarter of 2022 and production is expected to continue until the end of 2026.
Processing
The process design at the Meadowbank mill consists of two-stage crushing, grinding, gravity concentration, cyanide leaching and gold recovery in a CIP circuit with a current capacity of 3.6 million tonnes processed per year (9,840 tonnes per day).
The Meadowbank gold processing plant uses conventional technology adjusted to the Arctic climate. After two stages of crushing and grinding, any "free gold" is then removed by a gravity circuit. The remainder is leached using cyanide, with the gold captured using carbon-in-pulp technology and electrowinning cells. Gold-plated cathodes and gravity concentrate are smelted in an induction furnace and poured as doré bars.
The CIP tailings are treated for the destruction of cyanide using the standard sulphur-dioxide-air process. The detoxified tailings are then pumped to the permanent tailings facility. The tailings storage is designed for zero discharge, with all process water being reclaimed for re-use in the mill to minimize water requirements. Permitting for in-pit disposal of the Meadowbank mill tailings in the depleted Meadowbank pits was received and in-pit tailings deposition began in July 2019.
In 2021, new facilities will be added at Amaruq to support the underground project, including: new mine dry, surface ventilators, cemented rock fill plant, compressor room, new generators and new electric house. In addition, a high-pressure grinding-roll unit is expected to be commissioned by the second quarter of 2022.
Exploration
The Whale Tail deposit has been defined over at least 2.3 km of strike length and from surface to 915 m depth.
The Whale Tail deposit remains open to the west at depth, and to the east along a shallow plunge corresponding to the main ore shoot. A small portion of Amaruq's current mineral reserves and mineral resources are in the Whale Tail North structure.
The V Zone consists of a series of parallel, stacked mineralized structures striking northeast from near surface to as deep as 707 m below surface.
During 2020 at the Amaruq property, delineation drilling was completed at the Whale Tail deposit and V Zone, and conversion drilling targeted the extensions of both structures.
In 2021, the Company expects to complete 34,900 metres of drilling at Amaruq, including 23,900 metres of conversion and 11,000 metres of exploration drilling, focused on testing open-pit extensions and further underground potential of the deposits.
Elsewhere in the Kivalliq region of Nunavut in 2021, the Company expects to complete 20,600 metres of regional exploration drilling, including 10,000 metres of drilling in the Meadowbank area with a primary focus on investigating for new open-pit potential near existing infrastructure. Another 3,600 metres are expected to be drilled on other exploration targets in the region.