Rio Tinto Developing Diavik’s A21 Pipe
The Diavik mine is located 300 km northeast of Yellowknife, the capital of the Northwest Territories. The mine produces 6 million to 7 million carats/year of predominantly large, white gem-quality diamonds destined for use in high-end jewelry. The A21 pipe is being developed as an important source of incremental supply to ensure continuation of existing production levels.
The A21 pipe is located just south of Diavik’s existing mining operations. Development will require rock-fill dike construction to encircle the orebody, which is located just offshore of existing mining operations at Lac de Gras. The project will utilize the same technologies that were used to construct two other dikes to enable mining of pipes below the lake surface.
First equipment and supplies for A21 pipe development are scheduled to be transported to the mine site in early 2015 on the seasonal winter ice road. Planning calls for four years of dike construction and pre-stripping (2015-2018) to be followed by approximately five years of open-pit mining.
As of year-end 2013, the A21 pipe had an estimated 3.6 million metric tons (mt) of measured resources at a grade of 2.8 carats/ mt and 0.4 million mt of indicated resources at a grade of 2.6 carats/mt. Resources and reserves are scheduled for updating in the first quarter of 2015. The current mine plan calls for production to end in 2023.