The first of three new underground rapid excavation systems is now ready for full scale performance verification trials at Northparkes’ copper and gold mine in the Central West of New South Wales in 2012. Rio Tinto is developing new excavation systems as part of its Mine of the FutureTM program to significantly improve the construction and operation of underground mines. Rio Tinto Head of Innovation John McGagh said the significant new investment offers the possibility for a step-change improvement over conventional drill and blast practices.
“Depending on rock conditions, this system should provide a capability to excavate at more than double the rate of conventional methods,” McGagh said. “For example, in a typical deep copper orebody, the rate of horizontal tunnelling could be as high as 10-13 m/d using this new system. Aker Wirth is one of three partners with whom Rio Tinto is working to develop new equipment and systems for the rapid construction of deep underground mines.”
The other two partners in these rapid development projects are Atlas Copco and Herrenknecht (IM, May 2010, pp55-58).
This new tunnelling boring system trial has been integrated into a previously announced $90 million prefeasibility expansion study at Northparkes in August 2010 by Northparkes’ joint venture partners Rio Tinto and Sumitomo Group companies. McGagh said the trial will complete the final stage of performance verification of the new system.
The work is part of Rio Tinto’s Mine of the Future program, which aims to enable Rio Tinto to more effectively carry out exploration; more efficiently exploit resources; and to allow safer, faster and deeper underground operations whilst economically recovering valuable mineral resources from increasingly difficult deposits.
Aker Wirth Chief Executive Officer Christoph Kleuters said: “We are proud to have been selected by Rio Tinto as partner in this ambitious project. This system confirms Aker Wirth’s commitment to maintain our position as technology leader in hard rock excavation for the underground mining and tunnelling industry.”
McGagh said: “This is about The Mine of the Future program going underground, as we promised we would at the start of 2010. This system incorporates continuous mechanical rock excavation that will not damage new tunnel walls, while still providing the ability to mechanically install ground support in parallel with tunnel advance. Importantly for Rio Tinto, it provides an opportunity to introduce fundamentally safer processes into the underground mining industry.
“This announcement demonstrates Rio Tinto’s ongoing commitment to exploiting step-change technology to deliver superior shareholder value whilst improving both safety and environmental performance.”
The new tunnel boring system is expected to arrive in Australia in early 2012, and be operational with trials completed at Northparkes by the end of 2012. The system is 64 m long, has a maximum boring diameter of 6 m and has minimum tunnel dimensions of 5 m by 5 m. After the trial this technology is destined for use in other Rio Tinto underground mining operations internationally.