An underground innovation is making good headway to access a deep underground ore body at Fresnillo’s silver mine in Mexico. The rectangular tunnel boring machine (TBM), known as the MDM5000, which stands for Mine Development Machine, is capable of excavating a flat tunnel invert (5 m x 4.5 m) for immediate use by rubber-tired vehicles. The successful trial at this mining operation is the result of extensive discussions between TBM and mining equipment manufacturer Robbins, who designed and supplied the machine, with TOPO machinery and Fresnillo Plc.
“We decided to work with Robbins for their experience,” said Fidel Morin, projects superintendent for Fresnillo mine. “A lot of people have tried to provide these kinds of machines, but nobody has done it. Robbins used their experience and their skills to provide us with a rectangular profile machine.”
With more than 1,700 m of advance thus far at rates up to 52 m in one week and 191 m in one month, the MDM is significantly faster than drill-and-blast operations, according to Robbins. The MDM is excavating in andesites and shales with quartz intrusions that have defeated earlier attempts to excavate these tunnels with heavy roadheaders.
“We’re making history,” Morin said. “Fresnillo is always looking for new technology, and we believe that the usage of the MDM5000 is going to be something extremely successful, not only for our company but also for the mining industry.”
While the MDM5000 has proven itself in underground mining, Robbins sees it as just one component of a new approach. A multifaceted solution for underground mine development would see the utilization of Robbins shaft boring machines for ventilation and mine access, as well as TBMs and conveyors to directly mine the ore body and transport material. The unique TBMs would be lighter, more mobile, and able to bore inclines.
“It’s all about reaching first ore quicker, and then economically mining the ore body while reducing tailings,” Robbins President Lok Home said. “Mechanized tunneling machines have the potential to revolutionize the underground mining industry.”
The MDM5000 TBM is the latest in a long history of underground innovations from the company, dating back to 1952.
Watch the video at www.youtube.com/watch?v=mgFopWaf220.