Technology advances are essential to mining’s necessary transition from massive openpits to large-scale underground operations and an industry veteran says another key step has now been taken.
“We are for the first time surveying the [block] cave in a similar manner to the way that people survey an openpit. We haven’t really been able to do that before,” 40-year industry veteran Tony Diering told a webinar audience.
“It’s pretty exciting.”
Last year’s 9th International Mass Mining Conference (MassMin) in Sweden heard the vital global copper-mining sector had started transitioning from large-scale openpits to underground caving operations and mines such as Freeport-McMoRan’s Grasberg mines in Indonesia (up to 37 million tonnes per annum) and Cadia in Australia (33Mtpa) were demonstrating lowest-quartile operating costs at huge scale. “New mines must operate as ore factories safely and reliably to be competitive, producing at production rates and operating costs comparable to today’s pits – 75,000 tonnes-plus of ore per day at US$8-15/tonne opex,” the event heard.
Speaking on a webcast hosted by Canada’s Ideon, a fast-growing technology company applying muon “rock x-ray” tomography in mineral exploration, block caving, geotechnical and other areas, Diering said the increasing size and complexity of caving operations meant accurate surveying of deep rock masses, exposed surfaces of excavated voids, or backs, and extracted material in muckpiles was only becoming more critical.
The webinar featured leaders from Evolution Mining’s Northparkes copper-gold block cave mine in New South Wales, Australia’s first block cave when it started using the method in 1997, including retiring general manager Rob Cunningham who worked at Northparkes in 1999 when a cave roof collapse caused an airblast that resulted in four deaths.
“I was a survivor of the air blast,” Cunningham said. “I was on the extraction level … when the air blast happened.
“We can't change history but we can adapt technology to prevent repeats of the past.
