UNDERGROUND DRILLING
Drilled metres
The mobility of the new Boart Longyear MDR700 is a time-saver when moving from hole-to-hole using an agile Manitou dieselpowered four-wheel drive carrier
Paul Moore reports on new machines, new methods and new software in underground development, exploration and longhole drilling
As stated many times before in IM, there is much to be learnt from the tunnelling industry in mining, especially with regard to mass excavation and lateral development. Sandvik’ s iSURE™ software( Intelligent Sandvik Underground Rock Excavation software) is a computer program that spans the tunnelling, construction and mining drill and blast sectors in terms of process control. It produces all the data needed for an optimised drilling and blasting cycle.
“ The full-featured iSURE software utilises your drill rig’ s data collection to improve the work cycle and the drill and blast excavation process. It also has an optional toolset for geological analysis( iSURE GEO), a tunnel profile 3D scanning system( iSURE 3D SCAN) and an interface to a third party blasting vibration feedback system. iSURE software capitalises the improved accuracy of iSeries rigs for drill and blast usage.”
The company adds:“ Together the iSURE software and DT922i tunnelling jumbo, the newest addition to Sandvik’ s extensive tunnelling offering, create a combination which change the future of tunnelling. The fully automated DT922i tunnelling jumbo brings customers true tunnelling quality, reliability and exceptional versatility. With a new articulated carrier, it features a next generation cabin supplying 25 % increased visibility, and noise level of less than 69 dB at all times.”
In the Blominmäki underground wastewater project in Finland, Lemminkäinen uses two Sandvik DT1131i jumbos, Sandvik iSURE software, technical support and aftermarket services from Sandvik.“ Working closely together is important to ensure that the equipment, systems and support meet the needs of the customer. The Sandvik equipment provides the tunnelling capabilities Lemminkäinen needs, while the Sandvik iSURE system is there for the planning and analysis for the complete tunnel project. It’ s a cooperative relationship with a focus on excellent productivity and safe operations.”
In an effort to stay at the forefront of mining technology, Sandvik has also introduced a new OptiMine module: the Drill Plan Visualizer, which displays both drill plans and drilling results in an easy-to-read, user-friendly way. Plans are easy to edit and can be transferred to the drills automatically. This allows customers to see real-time drilling data immediately, and in turn they can optimise their processes constantly.
Sandvik’ s electric jumbos at Borden
Goldcorp has designed Borden Lake to become the world’ s first all-electric underground mine when it reaches commercial production next year, an undertaking the company expects to not only help minimise community and environmental impact but also improve health and safety for employees – all while boosting Goldcorp’ s bottom line.
By the time Borden is in full production, there will be no diesel-powered equipment underground. A combination of tethered electric and quick-charge battery-powered equipment will comprise the entire fleet. By eliminating diesel underground and fully electrifying Borden, Goldcorp anticipates a 70 % reduction in greenhouse gases and annual savings of 2 million litres of diesel fuel and 1 million litres of propane. The company also expects to save 35,000 megawatt hours of electricity yearly, due in large part to drastically reduced ventilation needs.
Goldcorp Senior Project Engineer Maarten van Koppen:“ Electrification is the ultimate winwin, especially complemented by innovations like ventilation on demand and full connectivity. The main benefits that we see with going electric are certainly the elimination of fuel, reduced maintenance, reduced greenhouse gases, reduced power consumption, and of course the biggest one is the elimination of diesel particulate matter in underground environments, which is hugely beneficial to the health of the workforce. We were able to eliminate a return air raise and our intake raise, we could reduce the diameter from five metres to four metres, so there’ s big cost savings to be had if you set it up right from the get-go.”
Miner Randy Harrison appreciates the absence of underground emissions at Borden after working in conventional diesel mines across four continents since 1980.“ This is like no other underground environment I’ ve ever worked in,” Harrison says.“ The air is so fresh.” He’ s behind the controls of a Sandvik DD422iE, one of two identical units Goldcorp depends on to develop Borden’ s access ramp.“ The computer setup and the preciseness that you can get on the face, bar none, best jumbo they got around,” says Harrison, who’ s operated development drills since 1989.“ Sandvik has been on the cutting edge right from day one since I started operating them.”
Borden Project Manager Luc Joncas calls the jumbo the star of the fleet.“ It enables better accuracy, more control, consistency from crew to crew. For us it enables also a safer operating workplace. We start from a fresh face with virtually no bootlegs. We manage the profile better and have less overbreak. It allows us to optimise the drilling pattern. Our holes are higher quality.” The Sandvik DD422iE is connected to the grid at Borden while drilling, during which the jumbo charges the battery it uses to manoeuvre between faces.
“ We thought charging-while-drilling was a great concept, something that could potentially be very valuable in other equipment in the future,” Joncas says.“ I was impressed that the jumbo can handle multiple voltage standards. We had a training camp at a mine with a 600- volt standard, and the jumbo works equally well on the 1,000-volt network here.” The rig’ s fully integrated battery technology means no change-outs, a safety and productivity benefit, Joncas says. He also cites the regenerative braking system as a plus and says the electric driveline in Sandvik DD422iE makes it much easier to maintain than conventional jumbos.
32 International Mining | JUNE 2018