When will we start to see all-electric underground mining? That was the opening question put to a high-powered panel at the recent AusIMM 2023 Underground Operators Conference. And the answer was, probably sooner than you think.
“There is a strong belief that within the next 10 years all mines in Australia will be in the new paradigm … and diesel will be well down the superseded path as compressed air mining equipment was in the 1970s and 80s,” veteran mining engineer Adrian Pratt said at the outset.
IGO head of technical services Chris Carr was more bullish. The company’s A$1.3 billion acquisition of Western Areas last year delivered it the Cosmos nickel project near Leinster in Western Australia.
“Cosmos … is in a unique position to try and electrify in the next couple of years,” Carr said at the conference in Brisbane, Queensland.
“In fact, our late CEO challenged us to do that by 2025.
“We don’t know what can’t be done.
“So we’re still going for it.”
It’s fair to say IGO is not alone in its desire to put its foot down.
There is a lot about the energy and collaborative spirit being poured into the industry’s pursuit of non-diesel underground mining that would please former IGO chief Peter Bradford, a respected and forward-thinking industry leader who died unexpectedly last October.
Carr and fellow panellists, Rio Tinto’s Danie Burger and Jayde Webb from South32, expertly canvassed the range of barriers that need to be overcome to achieve the sort of fast transition being talked about by sections of the industry.
But it was Carr who most succinctly stated why the shift could come soon now that initial forward momentum has replaced inertia. In fact, a single word pretty much nailed it: Wittenoom.
The former general manager of IGO’s flagship Nova nickel-copper mine in WA said the one-word epitaph for thousands of asbestos-related deaths connected with historical mining in the WA town should be defining the overriding safety case for electric mines.
“We’re seeing that diesel is being banned by cities in Europe [by] 2030,” Carr said.
“This is one of those things that’s still emerging that I don’t think we quite get.
“We have the opportunity to eliminate diesel particulate matter [in underground mines] altogether.
“And for me, that ought to be enough.
“That was the first driver that we started with.”
Webb, South32’s mining technology practice lead, said: “Within South32 we talk about our safety guarantee and when you put a safety lens to it, it can change the perspective [of] the decision you are making.
“The diesel particulate exposure is probably what it should have all been about in the first place.
“There are 40 toxic pollutants in diesel exhaust, 1.2 million Australian workers are exposed to this each year, it’s our second largest carcinogen in Australia and 250,000 Australians in the mining industry are exposed to this.
“These are the facts.”
The conference heard that much work is underway to reinforce the economic case for electric-vehicle replacement of utility, ancillary and primary diesel fleets at underground mines.
This is not just about the relative power, speed and payload of like-for-like EV substitutes. Life-cycle costs associated with these are unknown.
Miners and contractors need to account for enormous sunk investment in legacy equipment, infrastructure and asset management systems.
“If you look at the size of some of the fleets we have to replace and the amount of equipment that is readily available for us to replace those fleets, it will take a certain amount of time,” said Burger, Rio’s chief advisor underground technology and a former senior equipment manufacturer executive.
“It’s going to be different for greenfields mines versus brownfields mines that don’t have the infrastructure in place,” said Webb.
“[At current mines] it’s going to be linked to your fleet replacement schedule and how you use your equipment.
“So I don’t think there is one answer, but I do hope it [widespread fleet electrification] happens within the next 5-10 years.”
Webb said more than 20 Electric Mine Consortium (EMC) projects included efforts to stimulate new sourcing avenues around incumbent diesel-equipment supply channels, to try to bring more innovation and dynamism to the table. South32 is among a dozen mining companies and 10 service groups in the EMC, formed in 2020 to help speed delivery of technologies seen to be needed to enable miners to meet ambitious scope-one carbon emission reduction targets.
At least 20 further projects awaiting equipment deliveries are in the pipeline.
“I’d say right now the rate-limiting step is … the OEMs [original equipment manufacturers],” Carr said.
“We don’t have the equipment to trial, so we don’t have the equipment to demonstrate … in front-line applications, and that to me is the rate-limiting step and that is the biggest risk to us in electrifying Cosmos in the next two-and-a-bit years.
“The OEMs need to gear up for this. They need to be sure that the demand is there. There is a bit of chicken and egg, but I think the time is rapidly approaching when the demand is going to be there and it’s going to come quick.”
While battery-hybrid power systems, electrification in conjunction with clean-energy procurement, hydrogen and other options are being looked at for surface mines, hydrogen is not seen as a realistic option underground. Mines were running electric haul trucks in Australia and Canada in the 1980s, before larger and larger diesel vehicles became the industry’s standard-bearers.
Matching the high energy density and versatility of modern diesel-engine underground mine trucks and loaders is the major challenge. Smarter electrification options, batteries and battery-charging systems are now being pushed through development and commercialisation gates at a relatively brisk pace.
“The technology continues to evolve,” gold major Newcrest Mining’s mining manager, Matt Ireland, said at the conference. Ireland presented a paper on the introduction of a new electric loader at Australia’s highest-grade copper mine, CSA Cobar, in western New South Wales, where he was previously mining manager.
“We started the journey [at CSA] back in 2018. The machine and battery and charging infrastructure arrived on site probably mid-to-late 2021, and in that time there was an increase in the technology in terms of battery capacity by 15%.”
Carr said: “Looking further forward into the future, if we look at different battery chemistries like titanium oxide as a cathode, and we can go to ultra-fast charging … it may be possible to pull in and in 10 minutes get enough charge to go up the decline.
“In the short term I think technology such as BluVein [dynamic charging] will be essential.
“If you look at the amount of energy that a truck needs it’s quite a considerable amount. A diesel tank lasts quite a long time. We probably don’t have batteries that are going to do that. So if you’re going to be doing a lot of decline haulage, something like BluVein trolley-assist I think is probably going to be how we achieve that.”
Webb said EMC members were putting a range of charging technologies and methodologies through their paces.
“I think we need to use technology – software, etc – to help us to not over-engineer electrical infrastructure,” she said.
“We must be able to use a standard approach … to either use our incumbent 1000-volt electrical starters underground, and infrastructure already there, or integrating and optimising our system, otherwise we’re going to create a Frankenstein of charging systems underground … and that’s going to be impossible to build a business case for anybody.”
