A landslide at Rio Tinto’s Bingham Canyon mine in Utah has resulted in the evacuation of about 100 workers and contractors on Wednesday night.
An excavator operator raised the alarm after spotting material movement in the mine’s lower pit.
The movement, in which an area of about 90 metres wide slid almost two metres, halted operations overnight as a precautionary measure.
Kennecott spokesman Kyle Bennett said this slide is not expected to further affect the mine’s production.
The copper mine made headlines on April 10 when over 135 million tonnes of rock and dirt slid down the north-eastern pit wall.
But the company was prepared, predicting the slide would occur, pre-emptive measures were taken to ensure employee and site safety.
The April landslide suspended operations at the site prompting employee layoffs and cutbacks.
Production has also taken a hit with Rio revising its guidance to 150,000 tonnes of copper concentrate in 2013, expecting incremental increases to about 150,000 and 180,000 tonnes in 2014 and 2015.
Since the slide remediation works have begun, rebuilding heavy vehicle roads which is scheduled for completion by quarter one 2014 and the removal of ore which expected to be completed by the end of 2015.
It is estimated the mine will see a 50 per cent reduction in output as a direct result of the first landslide.
The clean up
A disaster of this scale has never before been dealt with in the mining industry, and required an innovative approach to deal with the clean up.
The safety of Rio Tinto's employees was of utmost importance to the mining operation, and dozer operators could not safely work in the slip area.
However, while the clearing of the 98 million cubic metres of rock and dirt was an unprecedented challenge for the mine - remote control of their dozers was the logical option.
This is where an Australian development on mining dozers was put in place, and through the clever technology developed by Australian company Remote Control Technologies and installed on their Cat dozers supplied by Wheeler Machinery Rio was able to start dealing with the aftermath of the landslip.
RCT was able to design and manufacture three dozer remote interfaces and four remote kits to suit the Caterpillar D8T dozers used at the mine site together with spare remotes and support parts, prepare the necessary documentation and ship the equipment, all in a very small time frame.
According to RCT's managing director, Bob Muirhead, it took a "whatever it takes" approach, pushing the company to reduce its normal deployment lead time from ten weeks to just three, to deliver a remote control solution to the disaster struck mine.
It seems incomprehensible that the WA company was faster to react than some local suppliers, but according to Wheeler, who provided the remote dozers for the mining project, RCT was both faster to react and had better technical support.
Once on site, installation, commissioning and training were completed in three weeks by the two man RCT team, equipping Wheeler and the mining company's dozer operators with the skills necessary to clear the landslide in the safest manner possible so they could resume normal mining operations and staff could get back to their work.
"It was easy to work with the RCT team, the implementation went seamlessly and they were keen to share their knowledge and experience during the training, making us feel confident with the operation of the equipment," Wheeler Construction and Mining Technology's general manager, Greg Evans, said.