Automation is changing the face and pace of haulage, making mines safer, more efficient and profitable. (Photo: Sandvik)

E&MJ explores the growing opportunity for new haulage technologies and concepts underground

By Carly Leonida, European Editor

As the old saying goes, if you always do what you’ve always done, you will always get what you’ve always gotten. In the past, what we’ve always gotten from mine haulage has been good enough, and there has been little incentive to break away from tried and tested methods (truck, conveyor, skip or rail) for material handling underground.

While there has always been more variation in underground haulage methods than those used in surface mines, as operations delve deeper and pressures surrounding cost, safety and environmental performance mount, there is a growing business case for new technologies like automation, battery electric and ultra-clean diesel engines, and also for more innovative haulage concepts.

“Sustainability with all of its different aspects has started to play an ever-increasing role in mining companies’ investment decisions during the past 10 years,” said Pia Sundberg, product line manager for trucks at Sandvik Mining and Rock Solutions.

“Generally, we see a shift toward larger equipment in underground operations, and also haulage equipment is expected to support mines to reach their more demanding productivity goals. That requires productivity, reliability and low total cost of ownership from the loaders and trucks.

“Practically all of our customers are talking about, and requesting, cleaner technologies now. Local legislation is a key driver, as well as the general proactive approach toward environmental issues.”

Jim Fisk, executive chair of Rail-Veyor Technologies Global, reported similar findings. “Today, mine executives are more concerned than ever with the environmental factors of a haulage system whether it is for a brownfield or greenfield operation,” he said. “I think that’s the biggest change I’ve seen in the last few years.

“There was always a consideration to make mines, and thus haulage systems, safer and more economical. However, the familiarity of what was done in the past always holds a big emotional sway in the discussion.”

Lisa Youngblood, executive director of marketing and communications at Rail-Veyor, agreed: “With investors becoming more and more interested in the environmental, social governance (ESG) of a company and its supply chain, how a supplier sits within that ecosystem is very important. When you can marry safety, environmental consciousness and economy, it gets attention. And, I’d add that, since the pandemic, automated systems are also being looked at as a serious need.

“In mining, there are so many perceived risks when it comes to adopting ‘new’ technology. It’s not generally something that mine operators want to do. The push typically comes from the top management as they hear concerns of the communities where the mines are located or from investors.”

Optimizing Traditional Haulage Methods

Flexibility and low investment costs are among the principal benefits of truck-based haulage. Units can be easily moved from location to location, without permanent infrastructure that, for example, skip or rail-based solutions require. They also offer redundancy in the case of breakdowns. However, all mines are different, and the size and shape of the orebody as well as the mining technique and mine plan over the life of an operation will greatly influence the haulage method selected.

Aside from the obvious environmental benefits offered by battery-electric and advanced diesel-engine technologies, automation probably has the greatest potential to affect change in truck fleet performance.

Jouni Koppanen, product line manager for underground automation at Sandvik Mining and Rock Solutions, joined the conversation. “With the huge developments in digitalization and connectivity, the potential to increase safety, productivity and overall efficiency with less equipment breakdowns is being proven very successful at more and more sites,” he said. “This also convinces other mining operations that automating fleets provides a high return on investment.

“In addition, there is a shift in the appetite of the mining industry. We are seeing more planning for automation from the prefeasibility phase, and more implementation of automation. Mining deeper and in more challenging conditions underground requires a high degree of operational flexibility, mobility and adaptivity, which are the main focus of Sandvik’s AutoMine and OptiMine offering with mobile equipment fleets.”

Sandvik’s AutoMine product group for autonomous and remotely operated mobile equipment includes AutoMine Underground and AutoMine Surface Drilling.

AutoMine is integrated with OptiMine — Sandvik’s digital analytics and optimization suite — for production planning and automatic dispatching of tasks to AutoMine for production execution.

“Network technology is constantly evolving, which provides different types of technical solutions for different mining environments,” Koppanen said. “For example, Sandvik surface navigation now enables autonomous underground machines to also work on the surface with seamless transition from underground to the surface.”

Sandvik is also utilizing developed network technology to provide mines with the ability to operate automated machines from several locations and over short or long distances, which gives more flexibility for planning at large-scale operations.

Besides trucks, shaft hoisting remains one of the most cost-effective and enduring methods for material handling, particularly when mining a large orebody deeper underground.

From a sustainability point of view, hoists can be run using renewable or sustainably sourced electricity to eliminate fossil fuels. However, they require a significant capital investment compared to trucks, and they lack the flexibility of mobile haulage. Then again, truck operating costs are greater than those associated with hoists.

Doing Haulage Differently

Ventilation is another huge cost consideration. At underground operations, air laden with dust and diesel particulates must be removed and fresh air brought to the face in order to sustain working conditions. However, ventilation shafts are a huge expense. If the haulage method selected does not contribute to air contamination, how much could a mine operator save through ventilation? And, if the haulage method can be situated in a contaminated air drift, there is an added benefit.

“Obviously every mine operator wants more for less,” Fisk said. “That is how they make a profit. If alternative haulage methods don’t require more ventilation and/or have reduced energy consumption, then the mine can make money with a lower cut-off grade of ore. That in turns gives more life to existing mines.”

While Rail-Veyor’s technology is not new (the concept can trace its roots back to the 1960s), it is still yet to be considered mainstream. However, the company has experienced a surge in interest recently and high-profile success stories like the haulage system at Agnico Eagle’s Goldex operation in Canada (detailed in E&MJ February 2021), provide an example of what can be achieved if mining companies are willing to look and think outside of the box.

The Rail-Veyor system consists of a very low-profile train running on a 40-lb rail. It is fully electric, so the environmental benefits include reduced ventilation requirements for underground operations and, for surface applications, there is no water usage required as the system doesn’t produce dust.

Rail-Veyor described its technology as “TrulyAutonomous.” In practice, what this means is the system is programmed from loading to unloading and monitors itself; no operators are required.

“We optimize the system for the tonnage requirements the project needs to meet,” Youngblood explained. “Because it can navigate difficult terrain, around tight corners and up steep grades, we can fit inside an existing mine route with little to no additional development needed.

“And, if the mine is new, and we get in on the ground floor of mine planning, we can change the way mine haulage is done to take advantage of all our benefits. This includes not needing to mine on a horizon or flat drift and then skip to other levels as with traditional rail solutions.

If operated according to the design specifications, Rail-Veyor systems are expected to last 20 years with no need for midlife overhauls. If the life of mine isn’t that long, then the system can easily be relocated or extended. Planned maintenance is mostly inspection-based.

“Traditional diesel haul trucks might be cheaper, but they won’t last as long without a midlife overhaul or needed to be completely replaced,” Fisk said. “And when you take into consideration the cost of construction and maintenance ventilation shafts and skips, the CAPEX is greatly offset.

“Our OPEX costs are far lower than any other method. We are 92% cheaper at one installation than the previous haulage method they had. It’s also cheaper to install than a conveyor because the light rail component of the Rail-Veyor system does not need the infrastructure that a conveyor does.”

Changing the Way We View Haulage

Have you seen a shift in miner’s attitude toward alternative haulage methods over the past 10 years?

“I’d say miners are more aware and more accepting of viable alternatives,” replied Youngblood. “It has really changed in the last two years with the increased demand for ESG requirements by stakeholders. Environmentally minded investors are pushing the agenda.

“Additionally, there has been a huge shift in attitudes to the acceptance of automated systems because of the pandemic. Mine operations want to reduce the number of people that are in harm’s way, whether from rubber-tire vehicle collisions, fire or now microscopic invaders. As more technology is adopted in all areas of mine production, more operators are exposed to alternative methods and gain the familiarity, which is needed for widespread adoption.”

“I think over the next 10 years, we will see more diversification in mine haulage globally,” Fisk said. “I’ve heard experts say that material transport is 70% of mine costs. If that could be reduced in half, then mines would be able to go after lower grades of ore and still make money. That greatly evens the playing field for the juniors.”

Sandvik’s Sundberg was diplomatic in her outlook: “What we know is that developing new technology takes time, and to be able call new technology proven will also take time,” she said. “Simultaneously, innovations are needed because of the social responsibilities and also commitments to shareholders.

“This leads to an interesting situation where we need to be able to guarantee productivity, which, of course, requires proven equipment, but also at the same time to have courage to try something new. It’s very seldom possible for a mine to make a complete change in its operations, i.e., to change from truck haulage to something totally different. But, when it comes to entirely new operations, there is more room for new technologies.”

Sundberg added: “Having the ability to innovate and improve, and the courage to try new technologies will help us to reach end results which are successful for all. There are no shortcuts to success, we need to work for it, all of us.”