A trio of vipers—diesel and electric Pit Viper rotary rigs, that is—are drilling efficiently in preparation for Copper Mountain’s scheduled June 2011 production date
In spite of extreme cold weather arriving earlier than expected, Copper Mountain Mining Corp.’s careful planning, perseverance and high tech investment in reopening a 15-year dormant copper mine remains on track to achieve full production by June 2011.
Even a full six months before startup, the mine had begun rewarding the Princeton, B.C., area with new jobs and a promising outlook for an economic windfall from the billions of dollars of copper, silver and gold the mine will generate. It comes none too soon for this area of British Columbia, where the lumber industry has suffered from both pine beetle devastation and a downturn in the industry overall.
During its previous life, the open-pit porphyry mine yielded 770,000 metric tons (mt) of copper, 258 million grams of silver, and 20.7 million grams of gold from 23 years of continuous production before it closed in 1996, when copper prices were low. Exploration in 2006 by its new owner, however, promised the mountain would reward the company with another 17-years’ worth of production from its untapped mineral deposits.
Data-based Confidence in Projections
Combined evidence from past drilling and modern exploration convinced stakeholders there are still at least 680,000 mt of copper left, with precious metal credits of more than 12.8 million grams of gold and 127.6 million grams of silver.
Copper Mountain President and CEO James O’Rourke said the company anticipates full production to reach 32,000 mt/d, amounting to over 45,000 mt of copper a year and reaping significant amounts of gold and silver as by-products. With operational and financing costs totaling about $1.30/lb, the copper will sell at about $2.80, which O’Rourke notes is a significant margin.
The overwhelming evidence there are significant resource deposits yet to mine come from nearly 5,000 historical drill holes combined with more than 400 of the company’s own. Continued exploration of the deep-seated porphyry in the fall of 2010 further confirmed extrapolated predictions. And the life of mine strip ratio is estimated to be just 2:1.
High Profitability, Low Risk
Although reopening a mine of this size is a formidable task, the project did come with some built-in benefits, such as a ready, skilled workforce from previous mining operations in the area, as well as a pre-existing infrastructure at this site. Only 15 miles from the town of Princeton, a paved highway runs past the mine, and the site has ample water resources with an ideal location for processing the extracted ore. Copper Mountain partnered with Mitsubishi Materials early on, who provided security for the venture with financial backing and by ensuring the mine of a reliable buyer for the ore.
The conscious effort to reduce operational risk has been evident in every component of the enterprise, including choice of equipment. For instance, to move the 22.7 million mt of material by May 2011 in preparation for full startup in June, and then to move the additional 54.9 million mt anticipated during the first production year, all blasthole drilling has been relegated in a three-year agreement to Atlas Copco and its Pit Viper series, as well as all drilling rig parts, ancillary equipment and tools.
Gary Wright, the Atlas Copco sales representative for southwestern Canada, said, “It’s good for startups because it creates a partnership with the manufacturer and the mine. It includes everything from service to the steel and bits and allows everyone to work together.”
The first rig, a diesel-powered PV-271, which had been in operation since September 2010, was joined by its electric counterpart in November. A second electric model, a PV-351, completed the trio of Pit Vipers at the site in January 2011.
Alastair Tiver, Copper Mountain’s chief engineer, said a mix of electric and diesel is working well. “Use of electric allows us to lower operating costs,” he said. “The pit will be developed with a series of push backs, so having a diesel rig affords us some additional mobility to move a rig from one mining area to another, should additional drilling capacity be required.”
Strategy for Reaching the Metals
Peter Holbek, vice president of exploration and leader of the mine’s exploration teams, explained the three-pronged approach the company is undertaking to realize the company’s production goals. They have incorporated and expanded all three pits of the mine under one, all-encompassing “Super Pit.” First the company will drill in areas of known mineralization from the previous operation. Second, it will drill in outer target areas that, although drilled previously, were not fully explored. And third, it will go after deeper targets, confident in the corroborative data from the new and historical information.
The company purchased the original, diesel-powered PV-271 for its ability to move quickly into other areas without the need to relocate power. The decision to purchase electric-powered Pit Vipers was based on economy. Although they would have purchased a third PV-271, Mine Manager Art Pratico said the PV-351E was immediately available.
The current PV-271s, with 18,000 kPa air compressor packages, are well-matched to 270-mm Epsilon rotary bits, and allow quick clearing of the holes.
Pratico said the rigs are working well driving 7.62-m steels while smoothly operating on the mine’s 15-meter benches to stay ahead of scheduling goals. The electric model does give them the benefit of lower operating costs. Other than that, the diesel and electric perform comparably.
Copper Mountain Mining teamed with Atlas Copco for the complete supply of all required rock drilling tools. For the mine, this arrangement provided not only the convenience of a one-source supply but also meant Atlas Copco is in frequent contact with the company, maintaining instant access to customer support. Consequently, service is instantaneous, according to the two parties.
When asked how the PV-271 has been performing overall, Pratico said he is pleased with the machine. The diesel rig had already logged 1,200 hours of operation. It is also being used as a trainer. The PV-271’s high-tech upgrades give operators rich options without alienating those who are new to the series.
It “operates just like any other drill rig,” Pratico said, meaning it does not require a steep learning curve to train an operator’s skills to proficiency on a Pit Viper. Drillers can acquire proficiency with the rigs quickly is just one more contribution to helping the mine keep on track for its June 2011 deadline.
This article was originally published in Mining & Construction USA, No. 1/2011, a publication of Atlas Copco’s Construction & Mining business group.