Rio launches program for rapid underground development

Rio Tinto is expanding its Mine of the Future program to develop new equipment and systems for deep underground mines and has selected three partners to work on the project. Aker Wirth and Atlas Copco will individually work with Rio Tinto to develop two new tunnelling concepts and Herrenknecht will work with the Group on the development of a new shaft boring machine.

Rio Tinto’s Mine of the Future program (International Mining, September 2008, p24, and updated this January)  was unveiled in January 2008 and initially focused on the Group’s Pilbara iron ore operations.  The program is designed to create next generation technologies for mining operations that result in greater efficiency, lower production costs, improved health, safety and environmental performance, and more attractive working conditions.

Projects such as Resolution Copper in Arizona and Oyu Tolgoi in Mongolia will use underground block caving, requiring the construction of significant underground infrastructure prior to ore production. In anticipation of this need, Rio Tinto Technology and Innovation has been engaged in a long-running development program to improve significantly both the safety and speed of constructing underground infrastructure such as shafts and tunnels.

The two new tunnelling concepts from Atlas Copco and Aker Wirth will enable fast and cost effective tunnel creation. The shaft boring machinery being developed by Herrenknecht will combine rock excavation, rock transport and structural support – currently three separate processes into a single system. All three new concepts are a result of civil tunneling industry technologies combined with input from Rio Tinto mining experts and contractor partners Redpath and Cementation.

John McGagh, Rio Tinto Head of Innovation, said, “At the heart of our Mine of the Future program is industry-leading work to pioneer new technologies. The partnerships announced today will help us fundamentally change the world of underground mining by further improving safety and allowing more rapid construction of new underground mines. Our new partners will be very valuable in helping us to solve the challenges of developing block cave mines.”

The Rio Tinto, Atlas Copco and Herrenknecht teams will present information on their respective mining breakthroughs at the upcoming Society for Mining, Metallurgy and Exploration conference on March 1-3 in Phoenix, Arizona. IM will be attending and will report from there.

The new Aker Wirth equipment is based on the company’s extensive experience in underground hard rock mining and tunneling. Its machinery will combine the flexibility of a roadheader operation with the robustness of a tunnel boring machine (TBM) and uses the learnings of a previous version from the early 1990s. One of the most successful TBM applications in mining was seen not far from Phoenix in the 1990s when use was made of the technology at the Magma copper mine (now closed) near Tucson – a block cave operation.

Atlas Copco’s new tunneling machine, the Modular Mining Machine, is based on learnings from its previous Robbins Mobile Miner combined with many years of experience in a wide range of novel rock excavation techniques.

As International Mining has noted a number of times within its pages, TBMs offer considerable advantages, in the right application, for mine development. However, their use, since the first application in the early 1980s, has been limited.

Herrenknecht’s new Shaft Boring Machine combines synchronous mechanical hard rock excavation, muck transport and rock support in a single system. The innovative single-system concept offers significant improvements in shaft construction rates and safety while minimising technical risks. Dr. Christian Frenzel, Mining Applications, Herrenknecht recently told IM the company is getting involved in equipment for sinking vertical shafts, raise and boxhole drilling. “We have a couple of references for the Vertical Shaft Sinking Machines (VSM). These are mainly civil shafts, but one pre-sink for a mine shaft has been undertaken as well. The further developments aims for a muck discharge system which allows hoisting of skips to the surface to overcome depth limitations of slurry systems.”