Newcrest Mining has restarted processing at the Cadia gold mine in New South Wales following last month’s tailings dam incident.
The gold miner identified a breakthrough of material at Cadia’s northern tailings dam embankment on March 9, forcing it to suspend operations.
Newcrest restarted mining at the Cadia East underground mine last week as it continued to investigate alternate tailings locations.
The southern tailings facility has now been inspected, independently reviewed and assessed to be safe for tailings deposition, according to Newcrest.
“Increased monitoring has been implemented, with new real-time radar monitoring scanning the length of the wall for ground movement every 30 minutes, coupled with daily physical geotechnical inspections and regular drone surveys to verify the integrity of the wall,” Newcrest reported.
“Work continues on evaluating the cause of the northern tailings facility embankment slump. A prohibition notice issued by the NSW Resources Regulator on depositing tailings in the northern tailings facility remains in place.
“As a precautionary measure, construction of the first 15m lift of a 30m-high temporary containment bund near the embankment slump has been completed. Work on the bund is expected to be completed in the coming two weeks.”
Newcrest, which expects to be at full mining capacity in the coming weeks, is currently mining from Panel Cave 1 at a rate of 11 million tonnes a year (Mt/y). It started test and response production from Panel Cave 2 over the weekend.
The company is also continuing to evaluate the Cadia Hill open pit as a tailings facility.
“The pit, in which mining has ceased, is approximately 500m deep,” Newcrest stated. “Newcrest is progressing a permit to initially use the bottom 200m of the Cadia Hill open pit for tailings storage and to use it in conjunction with the southern tailings facility to provide enough storage capacity to enable Cadia to return to full production.”
Newcrest has not yet updated its production guidance following the incident.