TORONTO (miningweekly.com) – Joint venture (JV) partners De Beers Canada and Mountain Province Diamonds on Tuesday celebrated the Canadian government’s approval of the development of the C$650-million to C$750-million Gahcho Kué diamond mine, in the Northwest Territories.

Fifty-one per cent JV shareholder De Beers and 49% partner Mountain Province in a joint statement announced that the Minister of Aboriginal Affairs and Northern Development Canada, Bernard Valcourt, had approved development of the Gahcho Kué diamond mine as earlier recommended by the Mackenzie Valley Environmental Impact Review Board.

The federal government approval now 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.

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 the Northwest Territories. The diamond prospect is one of the largest new diamond projects under development globally.

It would employ about 700 people during the two years of construction and close to 400 people during its operations phase.

The project 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, containing about 49-million carats.

The project would have an estimated production rate of three-million tonnes of ore a year and 4.5-million carats a year over its estimated 11-year life.

ADVERSE IMPACTS

The companies said that given the expected 42-days processing time for issuing the land use permit to enable pioneer work to start, as well as the impact of the winter ice road on logistics, the JV was currently 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 were 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 was busy updating the 2010 feasibility study and expected to announce the results of an optimisation study early in 2014.

De Beers, a unit of Anglo American, already has two producing diamond mines in Canada, namely Snap Lake and Victor, in northern Ontario.

In South Africa, the company also on Tuesday announced the start of construction of a new underground mine beneath its openpit Venetia mine, in the Limpopo province. The $2-billion investment will extend the life of Venetia beyond 2040 and replace the openpit as South Africa’s largest diamond mine.