Ivanhoe’s Kipushi zinc mine in DRC officially reopens
The restart marked exactly a century since the mine first went into production.
A section of the northern dam wall at the Cadia mine, located in the eastern Australian state of New South Wales, collapsed into the southern tailings dam on Friday releasing a slurry of finely ground rock, water and a low level of benign processing reagents.
The information was provided by owner and operator Newcrest Mining (ASX:NCM), whose management issued a statement on Saturday saying that experts on site have observed no environmental damage and that there is no threat to personal safety.
Nevertheless, Australia’s biggest gold producer halted operations at the mine while a probe into the causes of the wall’s failure is being conducted by the company, officials from the provincial government and independent investigators. The miner recognized, however, that there were previous issues. “An area of the embankment slumped following the earlier identification of cracks in the dam wall during a regular inspection. When these cracks were noticed the site team quickly engaged an independent consultant geotechnical expert to assist our own Cadia geotechnical engineers with an inspection and preliminary assessment of the embankment,” the press release reads.
Even though the accident took place just a few days after two earthquakes of magnitude 2.7 hit the area, Newcrest did not mention any connection between these events. Back in 2017, the mine had to be shut down after it was hit by a magnitude 4.3 earthquake. It took about three months to bring it back to partial production.
At the moment, the firm is making sure the area around the tailings dam is secured and is implementing “a comprehensive geotechnical monitoring system.” In parallel, company staff is reaching out to local landholders and residents downstream of the tailings facility, to keep them informed about the breach.
“We are assessing the impact on our operations, and will provide an update when further information is available,” Newcrest’s brief states.
10 Comments
john metzger
2 years ago after Samarco — I ran through the scenario for “modern” tailings management (#Monitoring) .. 1. SatSAR – wide area monitoring. 2. TinSAR (smaller facilities or focused monitoring of areas highlighted as in deformation by SatSAR — very easy to implement. 3. Integration of other instruments, siesmos, GNSS, total stations, photos etc .. all easy to implement and integrate.
Monitoring allows for intelligence about events to be noted, detailed, and analyzed — learned from for ongoing and future operational needs.
We were looking at seismological info and radar data a couple years ago in Jackson, WY — at a civil site, very rudimentary — but results that easily were shareable and made sense …
What measures are in place for near real-time monitoring at the site now? Should be IBIS-FM, and TRE-ALTAMIRA SqueeSAR data …. and for the whole Tailings site and staff …. a wide area 20M dataset would be a great choice — very affordable …
My guess is to “repair” that TMF wall, and affirm the “safety” of that structure — it is about $500K so far ………..
Will you have workers there without an IBIS? and the historical SAR data available? ….. not at John’s mine …..
Richard Harkinson
The only information source [yet] is Newcrest including “a slurry of finely ground rock, water and a low level of benign processing reagents”. It’s a gold-copper plant with identified antimony levels in waste. The NSW EPA’s 2016 audit on the 17 polymetallic mines in NSW stated that operators should make public the mine’s Pollution Incident Response Management Plan. Newcrest hasn’t. Mine operators act according to the rigour of regulatory requirements so that Newcrest want to dump tailings at their proposed Wafi-Golpu PNG project into the sea.
LAMB
Another reason for Gold Mines to go to DRY STACKING TAILINGS. This happened in British Columbia, Canada, and the result is DRY STACKING of Tailings. For some reason, Mine Management seems to think that Tailing Dam construction can be scrimped on to save money – THIS is not the place to save on costs – just the opposite, construction must be so robust that it will withstand a 100 year event.
Dave S
Hi Lamb. Im not sure what you mean by “…the result is dry stacking”. Do you mean that moving forward, mount poly (the one I imagine you are referring to in B.C.) will be using dry stacking? Or do you mean the industry in Canada is pushing DST. So far, while we seem to be looking at it more seriously in Canada, we still have a hard time justifying it on larger scales, and also in light of the financials. We still predominantly use slurry, especially for the larger tailing producing mines.
Marc Lubaszka
Mining companies in other parts of the world have seen similar consequences when a dam collapses on them. It is good to hear there were no injuries. Thanks Valentina for getting us the story.
Lance Steel
If you looking for an affordable system for tailings dams/TSF’s, have a look at this new system that Maptek has recently released: https://www.maptek.com/products/sentry/. Pillar monitoring also available and itinerant option is also available for day to day or weekly checkups using 3D laser scanners.
Steven Walker
So we have the mining industry legacy “Ponds” the size of the Great Lakes practically and they want to make them bigger?? They need to go after High-grade Gold Mines like GladstoneGoldMine.com with FAR less of a debris field for the future inhabitants of the World to clean up….my opinion.
It’s the only industry that the leadership doesn’t understand by producing more and more product and flooding the market… they are suppressing the price trying to outdo themselves in production….seems crazy?
Why work so hard for 1-2 grams per ton?
David Jansson
In my 40 years of tailings dam experience it has never been good practice to have water against the toe of a tailings dam toe
Nicolás Reyes Madrid
Es lamentable este hecho, el claro de agua se ve muy cercano a los muros resistentes.. Esto puede haber generado el ingreso de partículas de agua aumentado la presión de poros, y por ende, disminuyendo la resistencia al corte del muro resistente.
Ian Home
Would be interesting to understand the detail of what had been identified in the earlier inspections. There appears to be an increasing trend in the industry of delayed decisions when performance issues are raised during inspections, audits etc. A proactive management approach should be paramount at operations and be planned and exercised in management routines.