Kivalliq region, Nunavut
The Meadowbank open-pit gold mine in the Kivalliq region of Nunavut – approximately 300 km west of Hudson Bay and 110 km by road north of Baker Lake – is Agnico Eagle’s first Low Arctic mine.
2016 production and costs
Production - 312,214 oz gold
Production costs - $701/oz gold
Total cash costs - $715/oz gold
2 years; another 7 years with Amaruq deposit
The Meadowbank gold mine achieved commercial production in March 2010. It has 0.7 million ounces of gold in proven and probable reserves (8 million tonnes at 2.69 g/t) as of December 31, 2016. Meadowbank is expected to produce 320,000 ounces of gold in 2017, and 165,000 ounces gold in 2018. At the Vault deposit, opportunities are being investigated to potentially extend production through year-end 2018.
At the Vault deposit, opportunities are being investigated to potentially extend production through year-end 2018. Extension of Meadowbank’s mine life will help bridge the production gap between the end of production at the mine and the anticipated start of production at a satellite mining operation at Amaruq, which will feed the existing Meadowbank mill.
Agnico Eagle has approved the Amaruq satellite deposit at Meadowbank for development pending the receipt of the required permits, which are currently expected to be received in the second quarter of 2018. Production is currently forecast to begin at Amaruq in the third quarter of 2019.
The Meadowbank property is underlain by Archean-age volcanic and sedimentary rocks. 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 granite plutons.
Gold deposits are found along two main structural features that cross the property – the Meadowbank Trend and the Pipedream Lake (Northeast) Trend. The Meadowbank Trend hosts the Goose, Portage and Vault deposits, which are the sites of initial mining. These shallow deposits lie within 7 km of each other. In all deposits, gold mineralization is commonly associated with intense quartz flooding, and the presence of sulphide minerals (pyrite and/or pyrrhotite).
Meadowbank has conducted surface mining from a series of three pits all within 7 km of the processing plant. Water retention dykes have been built to allow for mining beneath shallow lakes, using a unique in-water dyke construction method. Dewatering of Vault Lake, for example, has allowed the Vault pit to be mined since April 2014. The mine works year-round, using conventional drilling, blasting, truck and shovel methods. Waste rock is used for construction, or dumped in waste storage sites or previously mined-out areas. To minimize acid generation, the sulphide-bearing waste rock is encapsulated in permafrost and capped with an insulating layer of neutralizing rock.
The 11,000-tonne/day gold processing plant uses conventional technology adjusted to the Arctic climate. Any “free gold” is 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 plant includes both a cyanide recycling thickener and an air-sulphur dioxide cyanide destruction circuit to ensure that no cyanide escapes to the environment. All water from the tailings pond is pumped back to the plant for reuse, making this a zero-discharge system.
Exploration is being conducted at the Amaruq satellite deposit, located 50 km northwest of Meadowbank.