August 2010

A small window, a big opportunity

By C. Baldwin

Agnico-Eagle's Meadowbank gold mine in Nunavut went into production early this yearPhoto courtesy of Agnico-Eagle Mines

In a remote region 320 kilometres west of Hudson Bay lies the hamlet of Baker Lake, Nunavut’s only inland community. Seventy kilometres north of this is the Meadowbank Mine — a large-scale, open-pit mine run by Agnico-Eagle Mines (AEM). It is the company’s newest venture and is set to become its largest gold producer.

Although Meadowbank is AEM’s first tundra location, the company has plenty of experience in northern climes. Its flagship mine — LaRonde, in northwestern Quebec — has been in operation since 1988. AEM recently opened the Goldex and Lapa mines near LaRonde, as well as the Kittila Mine in northern Finland. Each northern mine, however, comes with its own set of challenges. “We have to deal with the extreme weather on top of the basic logistics of putting together a fair-sized project,” says general manager Denis Gourde.

Baker Lake is joined to the western shore of Hudson Bay by Chesterfield Inlet (a 200-kilometre-long inlet) that in turn connects into Baker Lake, which is part of the drainage for the Thelon River system. This salt water/freshwater corridor has proven vital to Meadowbank, providing a transportation route for barges carrying equipment and supplies to Baker Lake during construction.

However, the open-water season in the Arctic only runs from the end of July until mid-October. “Predicting the end of the season is always a challenge,” explains Gourde. “We have a window of 10 to 11 weeks, so we have to mobilize all the fuel, construction and operating supplies, and equipment parts on the barges over a very short season — everything we need for the year.” Last summer alone, 41,000 tonnes of freight were brought in to finalize construction.

Navigating this challenge has required precise planning and coordination. On February 27 of this year, Meadowbank poured its first gold bar — right on schedule.

A feat of engineering — and patience

A gold showing was initially discovered in the area in 1983, and interests in the project were purchased by Cumberland Resources, which began exploration drilling and environmental and engineering studies. In April 2007, AEM became 100  per cent owner of Meadowbank, acquiring Cumberland in an all-share acquisition valued at $710 million.

The 1,200 hectare Meadowbank property covers a portion of the 25-kilometre Meadowbank gold trend in the Woodburn Lake Group, an area underlain by Archean-age volcanic and sedimentary rocks. The Meadowbank trend hosts three main deposits: Goose Island, Portage and Vault — all shallow enough to be mined as open pits.

All three deposits lie beneath the shallow Second and Third Portage lakes, sections of which must be isolated by containment dykes and then drained in order to access the ore. Construction of the dyke system has been challenging due to the short summers. “Only 1,000 metres of dyke can be constructed over a season,” says Gourde, “meaning construction of the entire dyke network has been spread over three summers.”

“Initial stripping began in summer 2008 to collect raw materials for dyke construction and landscaping, and to collect material to produce aggregates for concrete. That summer, we finished the first dykes needed to isolate a complete arm of the lake and had de-watered it by May.”

Two seasons of dyke construction remained but the mine had already become fully operational as completion of the first dykes had opened up the Portage pit to production. “We’ve been working in the pit since then,” says Gourde. “At the end of 2009, we had 600,000 tonnes of ore ready to be processed.”

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