IM 2020 March 20 | Page 20

BATTERY AND ELECTRIC VEHICLES The Borden benchmark maintenance/worker interaction, etc? MvK: We expected buy-in from the operators, though the feedback was much more positive than anticipated. At the end of the day, people feel better leaving work because it’s a healthier work environment. This is the most important benefit of all. It probably helps attract and retain people at Borden as well. IM: Conversely, has the tethered/battery-electric equipment caused any issues in terms of flexibility/charging requirements at Borden? How have you overcome these? Do you expect to add/change the electric fleet at the mine as production continues? MvK: Of course, there have been setbacks, it would be naïve to think that the introduction of a lot of new technology would go without a couple of snags along the way. The way to overcome this is to partner with the OEMs and contractors, foster a ‘can-do’ attitude on site and persevere. The team at Borden has done some amazing IM: Outside of Borden, where else in the portfolio does Newmont have tethered or battery-electric equipment? What, if any, changes to mine design are required for this implementation? MvK: We operate battery-electric equipment at Musselwhite and Eleonore. Virtually all new underground mines stand to benefit from going electric. For existing mines, the business case of switching is much more of a challenge to compile. One of the prerequisites to extract full value out of going electric is a sophisticated VoD system and the ability to modulate air flows, which requires connectivity underground and a way to track equipment and personnel in real time. Quite often those upgrades are not straightforward for mines that have been around for years. In addition, the ventilation infrastructure is already in place so capital savings cannot be realised unless upgrades are required to grow or continue the operation. IM: Have there been any unexpected benefits of implementing the battery and tethered electric equipment on mine operations/productivity/ work over the last couple of years. Some of the adversity was in the chargers, which had to be replaced and tweaked before we got them to work. Harmonics on the mine grid from variable frequency drives for fans and pumps caused some of these on-board chargers to malfunction. Similarly, a custom-converted road grader has been causing a lot of issues in the controls and has caused a lot of headaches. The charging requirements are actually quite simple for the most part at Borden. The vast majority of equipment has on-board chargers that can be hooked up using the common jumbo plug. This greatly reduces complexity. There are some exceptions, for the personnel carriers for example, and those are manageable. There are still some machines that we are looking to replace with an electric counterpart; we expect the production drill later this year and we still operate diesel haul trucks. IM: Knowing what you now know after embarking on such an ambitious project, would you have done anything differently? MvK: What we know now, a couple of years down the line, is this whole field moves rather quickly. There are very few regrets with Borden, and certainly none of them are big ticket items. Electrification it is now a lot easier than when we started because the product offerings by the OEMs are a lot more extensive and there is a growing level of experience in the industry when it comes to electric equipment. The real question is what is the next frontier in the next mine of the future, and I think the answer is fully autonomous and carbon-neutral operations with perpetual performance improvements through gamification and AI, while meeting societal expectations regarding sustainability and wealth creation in the communities where we operate. Coordinator for Alamos Gold’s Young-Davidson mine, said he had been testing the Relay for around eight weeks – in rough environments and going up and down ramps and inclines on numerous levels of the mine. “Compared with diesel, I’m lost for words. Health-wise, in terms of the effect on employees underground, it’s amazing!” he told IM. “I have driven this unit all shift so far without charging it until shift end as it charges itself on a decline. I started it at 97% charge and, at the end of the shift, it was 33% – that’s amazing for travelling throughout the 5,000 ft (1,524 m) deep mine.” He said the machine takes 15 minutes on the fast-charge 650 V setting to get to near-full capacity, while there is a 240 V charging option that takes six to eight hours to hit the 100% mark. Aramine has decided to hedge its bets and devise both an on-board charging system as well as a battery change-out option for its miniLoader ® L140B. The 1.3 t capacity narrow vein loader has been in operation since 2017 in several mines around the world, with the on-board charger providing around four hours of continuous operation. This allows for the mucking of three to four faces in one shift, according to the company. The quick replacement system (QRS), however, features a quick disconnect battery module that boosts productivity further. “It allows running the machine full time without immobilisation during charging time,” the company said, adding that the QRS process takes about 10 to 15 minutes to carry out. In order to safely manipulate the battery module, Aramine’s R&D department is currently developing a Mobile Charging Station (MCS), the company said. “Compact and practical, it is equipped with a hydraulic crane for quick and easy changing and moving of the battery modules. The station is connected to the mine’s electrical network and is piloted easily be a radio remote control,” Aramine said. The launch of the MCS is scheduled for the middle of the year. Caterpillar, too, has come up with a mobile charging solution. It’s MEC500 offers ultra-fast battery charging with the 300-1,000 V output capable of providing up to 500 kW of power. Such a solution will come of use when the company The ‘all-electric’ Borden mine in Ontario, Canada, has been spoken about for years in mining technology circles. Having now achieved commercial production safely, on schedule and within budget, IM felt it was the right time to reflect on the project’s achievements. Maarten van Koppen, Manager, Energy & Sustainability at Newmont, was more than happy to provide some answers to our questions. IM: Goldcorp (prior to the Newmont acquisition) guided for significant ventilation cost reductions with the use of battery and tethered electric equipment at Borden. Have these projections been accurate in terms of the amount of air the ventilation on demand (VoD) system has had to push to the mine? MvK: In the study phase of the project an electricity budget was prepared for the life of mine and it was based on first principles. Unfortunately, there were not a lot of benchmarks available for an all-electric ramp haulage mine, which is one of the downsides of being one of the first movers. As it turns out, the predictions were too conservative as the actual electricity consumption was significantly lower than our expectations by about 40%. The savings are attributable to continuous improvement in the ventilation engineering, a more efficient VoD system than anticipated and lower energy requirements for equipment than originally anticipated. What’s interesting is that the instantaneous peak demand is close to what we anticipated, and we are working with the utility companies to expand the grid capacity at Borden to ensure we can continue to grow Borden as planned. 18 International Mining | MARCH 2020