Two-tonne slab of rock sloughs off face
A life-saving safety innovation pioneered at a Northern Ontario gold mine is catching on across the hemisphere.
Goldcorp Inc., owner and operator of the Musselwhite Mine, collaborated with MacLean Engineering, to design an engineered canopy for the work platforms at the rear of the AC-3 ANFO Chargers used at its underground mine. Goldcorp has been using the MacLean-built machines for nearly six years and has four of them at Musselwhite.
“The concept of the canopy was developed through discussions with Musselwhite and MacLean after we had a few miners injured from rock falling from the face during the loading cycle,” said Jeff Lewicky, Musselwhite’s mine superintendent. “There were also several near hits that also occurred.”
A couple of weeks after the canopies were installed, one of them proved its worth. As two night shift miners, Clayton Kitchkeesick and Bobbie Caissie Jr., were loading explosives into the rock from the work platform, a two-tonne slab of rock, about four feet by five feet, sloughed off the face they were working and dropped on the protective canopy. The miners were unharmed. “It saved both of their lives,” said Lewicky.
“It worked quite well,” said Dan Stern, MacLean’s product line manager in Sudbury. The canopy is designed to stop rock or any kind of debris falling off the face, he said.
The protective canopy was introduced in 2011 in conjunction with mine personnel who helped design it, said Alicia Wood, MacLean’s director of sales for North America. “We worked closely with Musselwhite to develop it. Musselwhite is prone to bursts off the face. It’s something they identified as an issue. We worked with them to develop a canopy as a way to offer added protection to operators.”
MacLean, well known in the industry for its 900 Series Scissor Bolter, has manufactured nearly 100 AC-3 ANFO Chargers for customers across North America and around the world. The machines carry tanks of ANFO (ammonium nitrate and fuel oil), a bulk explosive used to blast ore from mine rock. The AC-3 ANFO Charger backs up to the mine face where miners climb aboard a “man basket” or work platform on a hydraulic boom. “That boom allows you to travel along the face to load explosives in the holes,” said Stern, who describes the technique as the most practical way to load ANFO into blast holes.
Although the canopy over the man basket is currently an optional component, MacLean recently sold four of the machines with protective canopies in Latin America. “Lots of mines, especially in North America, are tending to go to these canopies,” Stern said. “The main goal is to keep all operators safe, to give them an extra level of protection.”
After inspecting the Musselwhite machine damaged by the sloughing rock, MacLean replaced the canopy. The machine has now been put back into service.
Stern predicts the canopy will eventually become standard equipment on the machines. “The case study we built at the Musselwhite Mine has helped sell this feature,” he said. “We’re building a case study for the ANFO canopy. The more information we can get back from mine sites on the use of these canopies, the better we can promote them as an added level of safety for the ANFO loading process around the world.”
According to Lewicky, the canopies should become the standard for the industry.
“I believe any other mining company would see the value in this added protection if they fully analyzed the risks associated with working at an unsupported rock face,” he said.
Situated 500 kilometres north of Thunder Bay, Musselwhite employs more than 800 people. It has been in production for just over 15 years and produced 270,000 ounces of gold last year.
The AC-3 ANFO Charger is powered by a standard Mercedes 904, four-cylinder engine, or with a Caterpillar engine. “It’s up to the customer who decides what brand of engine they prefer,” said Wood. The machine’s Clark Dana power train includes Dana 32000 transmissions and Dana 113 axles.
MacLean does its engineering and manufacturing in Collingwood and Owen Sound, while Sudbury serves as its sales and support base. The company recently opened an 84,000-square foot facility in Barrie for the manufacturing, warehousing and distribution of aftermarket parts.
