Gahcho Kué, a fly-in/fly-out remote mine site at Kennady Lake, on the Canadian tundra, about 280km north-east of Yellowknife, has now reached full commercial operation. Production is expected to last 12 years, during which it is expected to treat around 34 million tonnes of material containing an estimated 53 million carats (on a 100 per cent basis).* Full construction of Gahcho Kué started in the 2014/15 winter.
It is so cold in the area (temperatures reach minus 40oC) that an ice road is built each winter to enable the delivery of supplies – about 2,500 loads each year of fuel, construction supplies, mining equipment and other materials.
Lakes are used to flood the roads and then the water is allowed to freeze. The ice is more than 40 inches thick, and it needs to be, given that the trucks and trailers heading to and from the site can weigh around 55,000kg.
Open for just two months a year, the road is a 120km spur to Gahcho Kué from the road to De Beers Group’s Snap Lake mine, which was put into care and maintenance in December 2015.
To access the kimberlite deposits, the water level has been lowered in part of Kennady Lake, one of thousands of small lakes in the region. Some sections have been partitioned off and drained to reach the kimberlite by building a series of dykes, ditches, berms and ponds. But, as the water level has been lowered, clean water is pumped into another watershed north of the lake.
Gahcho Kué, which means ‘place of the big rabbits or hares’ in the local Chipewyan language, began in 1995 when Mountain Province Diamonds discovered the first kimberlite deposit, known as 5034. Three other deposits were discovered by De Beers Exploration two years later, with two of them, the Hearne and Tuzo kimberlites, having excellent economic potential. Extensive drilling and analysis followed and environmental permits were sought and granted for 5034, Hearne and Tuzo.
Canada is the world’s third largest diamond producer by value and the fifth largest by volume. The development of Gahcho Kué between 2006 and 2015 has already provided a C$440 million boost to the NWT economy, according to a recent socio-economic impact study conducted by EY for De Beers Group.
The mine was officially unveiled by De Beers Group Chairman and Anglo American Chief Executive Mark Cutifani, De Beers Group CEO Bruce Cleaver, De Beers Canada CEO Kim Truter, Mountain Province Diamonds CEO Patrick Evans, and representatives of First Nations and Metis communities in the Northwest Territories at an event that included 150 guests from across Canada and around the world.
*Scheduled Inferred Resources (1.2 million tonnes) constitute 2.7 per cent (1.4 million carats) of the estimated carats. The estimates are scheduled tonnes and carats as per the Life of Mine Plan approved in 2016.