LaRonde Extension – mine design at three kilometres

Abstract

Agnico-Eagle’s flagship LaRonde Mine is exploiting a world-class Au–Ag–Cu–Zn–Pb massive sulphide lenses complex. It is located in the Abitibi Region of north-western Quebec, approximately 650 km northwest of Montreal. With 5 million ounces of gold in proven and probable reserves, LaRonde has one of the largest gold reserves of any mine operating in Canada. These reserves extend from surface down to 3110 m and remain open at depth. The 2250 m Penna shaft, which is believed to be the deepest single-lift shaft in the Western Hemisphere, is used to hoist LaRonde’s ore production of ∼7200 tonnes per day. Current mining operations are taking place at over 2400 m below surface. In 2006, the decision was taken to sink a winze in order to access the ore below 2450 m. The new no. 4 shaft extends to a depth of ∼2840 m below surface. With the use of ramps the mine will access reserves as deep as 3110 m. Production from shaft no. 4 is scheduled to begin late in 2011, with the full production rate reached in 2013. It is expected that the LaRonde Extension will extend the mine life well beyond 2020. Sinking a winze shaft and building all the necessary infrastructure of a mine at a depth of over 2·8 km poses unique challenges, some of which are discussed.