Diavik Diamond Mine

BACKGROUND
 

The Diavik Diamond Mine is located in a region of continuous permafrost on East Island in Lac de Gras, Northwest Territories. Following diamond extraction from the kimberlite ore, the remaining “Processed Kimberlite” material is permanently stored in the Processed Kimberlite Containment (PKC) circumscribed by dams which have a waterproofing geomembrane. These dams are based on the permafrost and are built following the evolution of the mine.

SOLUTION
 

The design and construction of the dams have been modified with the use of a bituminous geomembrane. It allows the use of a variety of sealing materials and can be installed under a wide range of temperatures. Compared to the HDPE geomembrane COLETANCHE® liner grades of ES1, ES2 and ES3 have been used because construction bedding materials ranged from coarse sand, to till, to crushed rockfill material.

 

REASONS OF CHOICE
 

The COLETANCHE® geomembrane in this project, promotes:

- Installation in extreme weather conditions (rainfall, wind, cold temperature down -40°C or -40°F) - A wider range of materials to be used for the liner bedding and cover zones

- Easy to install and to repair

- High resistance to puncture and tearing
 

COLETANCHE® liners have been installed throughout the year, even during winter conditions at the Diavik site, COLETANCHE® can be installed for 10 months per year while HDPE 3 or 5 months per year.
 

Liner installation production rates range from up to about 3000 m2 per day in summer to 2000 m2 per day in winter. An excavation done to expose an installed ES1 liner in the temporary pond dam, indicated that the liner performed as expected in the dam structure. The liner exhibited a stress relaxation around the gravel size bedding and displayed a high frictional bond between the liner and bedding.