The remediation and upgrade work required to recommence use of Cadia East’s Panel Cave 1 (PC1) crusher chamber has been completed to a standard consistent with Newcrest’s emphasis on safe, strong and sustainable operations. Extraction of ore has now recommenced from two extraction drives in PC1.
On April 14, a large seismic event occurred near Newcrest’s Cadia East mine, an underground panel-cave operation located 25 kilometers (km) south of Orange, New South Wales, Australia. At the time of the event, all personnel working in the Cadia East underground mine moved to refuge chambers or safe areas. Newcrest’s geotechnical engineers inspected the mine accesses, certified those areas as safe, and all personnel were moved to the surface. An assessment was undertaken to determine the extent of damage caused by the seismic event before operations could recommence.
Newcrest submitted final ground support plans for the PC1 crusher chamber and extraction level, which were accepted by regulators, who amended a Prohibition Notice, allowing operations to recommence as areas are upgraded. Remediation and upgrade work continues on other areas in the PC1 extraction level, which is expected to be completed by the end of December.
Newcrest completed the “test and response” phase of the Panel Cave 2 (PC2) on July 19, with the ramp-up in production from PC2 continuing. This phase involved drawing approximately 480,000 metric tons (mt) of ore, while monitoring ongoing seismic response levels to ensure they remain within expected range and limits. The ore drawn during this phase of work has been transported via the underground conveyor system to surface where it was subsequently processed.
Newcrest expects Cadia East production rates to be restored to normal by the end of March 2018.