The benefits of electrification of mines include:

• Energy costs reduced by between 25 and 50 percent
• Safer working environment due to zero diesel emissions
• Reduced environmental impact due to zero diesel emissions
• Regulators are starting to favour all-electric mines
• Battery-electric machines offer enhanced productivity, performance and efficiency

“They are ready for remote upgrades, range performance improvements and more,” he says.

When it comes to the all-important economic arguments, a mine site stands to benefit in several ways from electrifying its mobile fleet. The cost of the ventilation systems, one of the most expensive aspects of developing and operating a mine, can be reduced by anywhere from 30 to 50 percent when using battery-electric machines that produce zero diesel emissions. Furthermore, less ventilation translates to a net reduction in electricity use and therefore a more energy efficient mine site overall. Meanwhile, the eliminated cost of buying diesel fuel equates to tens of thousands of dollars in savings – per vehicle and per year.

Maintenance costs are also reduced, since electric vehicle propulsion rigs have around 25 percent fewer parts than diesel propulsion rigs. Battery-electric machines produce one-eighth of the heat produced by a diesel machine, which can make new projects in deep mines, and mines with active geothermal conditions, more viable than they would otherwise be, due to the reduced heat factor.

Last but not least, regulatory bodies are gradually starting to favour mines that commit to an all-electric underground environment, resulting in approvals for permits that would otherwise be denied, along with a faster permitting process, both of which are potentially game-changing for mining companies around the world.

” “The fact that zero diesel emissions are inherently healthier and safer for mine site workers makes electrification inevitable.”

For its size, an electric motor has far more power and torque than a combustion engine. Since total horsepower does not have to be limited to mitigate ventilation system costs, far more power can be packed into a smaller machine. As a result, battery-electric machines can be designed from the ground up to handle more torque and power and therefore increase productivity in any given machine size class.

Although the advantages of electric mining speak for themselves, the industry is taking time to adapt. However, Kasaba says change is in the air.

Quality cells with the right chemistry

The inherent safety of Sandvik’s battery system starts at the cell level.

Artisan partnered with China-based CALB all the way back in 2015 as it looked to shore up a reliable and high-quality battery cell supply that could seamlessly fit into its battery system architecture.

Seven years on – half of that under the guise of Sandvik – Huff sees no reason to change.

“What matters from a battery system safety standpoint is consistency and high-quality cells,” he said. “That is achieved through high-volume manufacturing tied with automation and production controls that ensure the quality of production.

“CALB, which makes a lot of batteries for stationary and bus applications in China and globally, has all the compliance and testing completed on their cells and meet all the requirements from a safety standpoint.”

The battery cell manufacturer was also one of the early movers in the lithium iron phosphate (LFP)-based battery space, and Huff is keen to point out the safety benefits that come with using such battery chemistry.

“Our approach to battery safety, which is part of the standardised Sandvik approach for safety with ISO and other standardisation bodies, is to look, first, at reducing the severity of a potential incident or eliminating the hazard,” Huff said. “For us that means reducing the severity of a thermal runaway, which is primarily a chemistry choice.”

Thermal runaway is categorised as a chain reaction within a battery cell that occurs when the temperature inside a battery reaches the point that causes a chemical reaction to take place inside the battery. This chemical reaction produces heat, which drives the temperature higher, causing further chemical reactions to take place and further heat generation. Excessive heat generation at an accelerated rate can cause batteries to melt or be damaged beyond repair, or, in extreme circumstances, ignite and start fires.

With the potential to cause such an incident, thermal runaway preventions are often the first thing battery companies mention in safety briefings.

When plotting the main commercial battery chemistries against the heat-release-rate (HRR) on a graph, it is easy to see Huff’s point (see graph below). The rate of temperature rise (left) indicates the severity of a thermal event, with the higher the HRR, the harder it is to contain an incident, Sandvik says.

Backward-compatible benefits

Huff, a co-founder of Artisan, can contextualise the mining proposition better than most considering his experience in both electrifying the automotive sector and heavy-duty commercial vehicles – two sectors Artisan served prior to shifting focus to underground mining.

“A key difference is the level of serviceability required,” he said. “Mining is a very different world; you are separated so much from a nice clean shop with all the facilities and space to do work. With cars, there is such easy infrastructure in place; mining is not like that.

Rutqvist said the standardisation and commodification of Sandvik’s battery systems comes at the cell level, which leaves the company open to adapt and customise according to mining industry demands.

“If you take the market at a battery system level, mining customers don’t count in thousands, they count in hundreds,” he said. “Our average customer is big, and they expect to be very close to us when it comes to the product and the product development; our largest customers are very big and expect to have a say in the development and the requirements on the battery system.

“We’re happy to be middlemen for the battery cell, but we don’t want to be middlemen for the battery system design.”

Over the past decade or so – and going forward – this has enabled the company to take advantage of battery technology developments as they happen.

Haley-Anna Blinn – currently a BEV Applications Specialist at the Sandvik BHEV business unit and previously an Electrical Engineer at the Macassa gold mine in Ontario, Canada, which has one of the biggest battery-electric fleets in the world – has been on the receiving end of this.

“So much is changing in the battery space all the time,” she said. “I have only been involved for five years, and I have seen a lot of change.

“We recognise that, so it is important we design our systems to accommodate future design changes or even battery chemistry improvements when it comes to energy density.

“With the older vintage of equipment, there was a change of cell supplier at one point that resulted in cells with a different form factor.

“While this changed the number of cells in a module based on their characteristics, it was a change that was carried out seamlessly when the cells were due to be refreshed. The module had a similar form factor, so was backward-compatible from a battery system design perspective.”

5 reasons why electric mines are less costly

1. Ventilation systems can be reduced by 30 to 50 percent
2. Less ventilation translates to reduced electricity use
3. No diesel fuel costs
4. Electric vehicles require less maintenance
5. Electricity from renewable energy is becoming more affordable

Eriksson says, adding that the acquisition is advantageous to both parties.

While Sandvik will benefit from Artisan’s quick, agile approach to innovation and battery-electric vehicle expertise, Artisan will gain access to the established strength and operational experience of Sandvik, which has been the market leader in tethered electric underground loaders since 1981.

“The acquisition of Artisan battery-electric vehicles places Sandvik in a leadership position in terms of electrification within underground mining, which is clearly the direction in which the industry is heading,” Eriksson concludes.