Mining

Lapa hosts an underground mining operation.

Two mining methods are used – longitudinal retreat with cemented backfill, and locally transverse open stoping with cemented backfill. The diagram below shows the three stages of the mining method at Lapa.

In longitudinal retreat, sublevels are driven at 30-metre vertical intervals, linked by a ramp. Stopes are mined in 12-metre sections along the length of the orebody with variable widths using a pyramidal sequence, and backfilled with 100% cemented rock fill. In transverse open stoping, all of the ore is mined across the width of the orebody and filled with cemented rock fill. The ore is hauled on the 77 level (770 metres deep) and 125 level (1,250 metres deep). The average dilution for mining the reserves is expected to be 50%. The production rate is 1,500 tonnes per day.

Mineral Processing

Excavated ore is trucked to a dedicated Lapa plant at the LaRonde processing facility. The concentrates from Lapa’s gravity and leach circuits are sent to the LaRonde refinery to produce doré bars.

The LaRonde tailings disposal site was adapted to receive the Lapa material. A gold recovery of about 83% is expected for the Lapa ore.