Gahcho Kue

The project is located at Kennady Lake, approximately 300 km east-northeast of Yellowknife in the District of Mackenzie, Northwest Territories, Canada.

Consists of four main diamondiferous kimberlite pipes: 5034, Hearne, Tuzo, and Tesla of which only the first three are supposed to be mined. The kimberlite pipes lie beneath approximately 10 m to 15 m of water in Kennady Lake. Before mining can take place, the area around the pipes must be contained and dewatered by constructing a series of dikes around the pit positions and pumping out the water.

Mining will be by open pits extending to depths from surface of approximately 250 m in 5034, 220 m in Hearne, and 140 m in Tuzo. In total, the three pits would deplete 20 Mt of ore, or 65% of the 31 Mt Gahcho Kué resource.

Two dumps will be constructed, one west of the Hearne pit and the other a combined pile for 5034 and Tuzo, located south of 5034.

All earthmoving equipment will be purchased and operated by the owner. All equipment will be diesel powered.

A 250 mm drill will be used for primary drilling in waste and a 165 mm diameter drill for primary drilling in ore. A 64 mm secondary blasting drill rig will drill and blast any oversize rocks from primary blasting.

A fleet of shovels and front-end loaders will load ore and waste. Loaders will be of 12 m3 bucket size, able to load the 136 t haul trucks. Two loaders will be purchased, one dedicated to pit ore loading and the other to loading ore from the surface stockpile to the plant. The front shovels will be tracked face shovels of 15 to 17 cubic metre bucket capacity. The four loading units provide adequate loading capacity to cover loader breakdowns, overhauls, and other contingencies.

The ore and waste hauling fleet will comprise 136 t class off-highway trucks. Ancillary equipment will include 25 t road graders, 25 t rubber-tired dozers, a 35 t excavator with quick-couple rockbreaker attachment, and a water truck for road maintenance. Waste pile and load site maintenance will be performed with 65 t class track dozers.

The treatment plant design and costing is based on a capacity of 6,000 t/d. The process design includes the following facilities: primary crushing and conveying; primary scrubbing and screening; secondary crushing, scrubbing, and screening; high pressure rolls crushing; dense medium separation; fines thickening; water systems; recovery plant; security systems.

The luminescence data obtained for the gangue material show that high yields can be expected when x-ray recovery technology is used to process DMS concentrate.

The treatment facility will be situated in the vicinity of the mining operations and will be fed by mining trucks, which will normally tip directly into the primary crusher feed pocket. An appropriately sized ROM stockpile will be provided to allow flexibility in operations. It will operate 365 days a year, 24 hours a day, with annual shutdowns of 3 and 5 days for major maintenance, and will be fully enclosed and heated. The plant will be highly automated in order to limit the size of the workforce.

X-ray sorter concentrates will be transported by air to the nearby Snap Lake facility where the diamonds will be recovered using laser-based sorting machines. Final diamond concentrates will be exported to the off-site acidizing and evaluation facility, located in Yellowknife.