Name and Location
Gahcho Kué diamond project, Northwest Territories (NWT), Canada.

Client
Gahcho Kué Joint Venture (JV) – a collaboration between De Beers Canada (51%) and Mountain Province Diamonds (49%).

Project Description
Gahcho Kué, which is Chipewyan for ‘a place where big rabbits are found’, is located at Kennady Lake, 280 km north-east of Yellowknife and 80 km east of De Beers’ existing Snap Lake mine, in NWT. The diamond prospect is one of the largest new diamond projects under development globally.

The project consists of the Hearne North and South; the 5034 West pipe, the Central and North-East pipes; the 5034 South pipe; the 5034 North pipe; Wallace; and the Dunn Sheet, Tuzo and Tesla diamondiferous kimberlite pipes, sheets and dykes.

Gahcho Kué consists of a cluster of kimberlites, three of which have a probable mineral reserve of about 31.3-million tonnes, grading at 1.57 ct/t (about 49-million carats).

The project will have an estimated production rate of three-million tonnes of ore a year and 4.5-million carats a year.

The project design is based on the openpit mining of the 5034, Hearne and Tuzo deposits in a sequential fashion.

Mine plans call for the extraction of 233.7-million tonnes of waste and 31.3-million tonnes of ore over 11 years, using standard drill/blast and truck/shovel equipment and pit designs, which are similar to those of other openpit diamond mines operating in the area.

Ore will be fed to a three-million-tonne-a-year processing plant, with three stages of crushing, dense-medium separation and X-ray/grease diamond recovery circuits.

Supporting infrastructure includes a 14.1 MW packaged diesel power plant, a 1 350 m gravel airstrip, a five-bay truck shop, an emulsion plant, a 40-million-litre fuel storage facility and a 432-bed accommodation/office complex.

Value
An estimated capital cost of C$650-million to C$750-million.

Duration
The start of production is targeted for 2014.

Latest Developments
The Canadian government has approved the development of the C$650-million to C$750-million Gahcho Kué diamond mine, as earlier recommended by the Mackenzie Valley Environmental Impact Review Board.

The federal government approval allows the Mackenzie Valley Land and Water Board to start processing the applications for the land use permit and water licence required to construct and operate the mine.

De Beers and Mountain Province have stated that, given the expected 42-days processing time for issuing the land use permit to enable pioneer work to start and the impact of the winter ice road on logistics, the JV is reassessing the development plan to determine the optimal development schedule.

The Mackenzie Valley Environmental Impact Review Board approved the proposed 4.5-million-carat-a-year diamond mine in July, subject to measures and follow-up programmes.

The ‘Environmental Impact Review and Reasons for Decision’ report for the Gahcho Kué project, released on July 19, found that the project was likely to cause “significant adverse environmental impacts” and the panel set out measures required to mitigate such impacts.

This included reducing the impacts of the mine site and winter access road on caribou and its habitat, as well as reducing the project’s impact on the cumulative potential effects on the caribou population.

The panel called for follow-up programmes to address the impacts on water, fish, caribou, other wildlife and species at risk, as well as on socioeconomic indicators.

The JV partners are reviewing the report to better understand the implications of the measures and follow-up programme as recommended by the panel.

The project entails dewatering portions of Kennady Lake to access the three openpits, then backfilling one openpit and portions of a second openpit with waste rock and processed waste material from the mill, before refilling Kennady Lake at the end of the mine life and allowing fish to repopulate the lake.

The JV is updating the 2010 feasibility study and expects to announce the results of an optimisation study in early 2014.

Key Contracts and Suppliers
JDS Energy & Mining (feasibility study).

On Budget and on Time?
Too early to state.

Contact Details for Project Information
De Beers Canada Northern Territories director of external and corporate affairs Cathie Bolstad, tel +1 867 766 7325, fax +1 867 766 7347 or email Cathie.Bolstad@debeerscanada.com.
Mountain Province Diamonds, tel +1 416 361 3562, fax +1 416 603 8565 or email info@mountainprovince.com.