Automation is one of the most important trends in underground mining today. Operators across the planet are rapidly moving to automated systems to harness the productivity and safety gains achieved by removing humans from dangerous frontline operations.
But it wasn’t always so. Back in the 1990s, the potential for automation was a huge unknown. Only the most future-focussed mine owners and contractors were willing to invest time and money into investigating the potential for the then fledgling technology.
That’s when Australian copper and gold miner Northparkes began its automation journey. In 1998, the operation began cooperating in early industry trials investigating the viability of automated load, haul, dump machines (LHDs).
A little over 20 years on, the mine in New South Wales has become a shining example of all that automation can achieve.
Since switching over to an automated Sandvik LHD fleet in its E48 block cave mine in 2015, Northparkes has boosted output by nearly 20 per cent. Daily loader productivity is up 24 per cent, costs per tonne are down 23 per cent, and the problem of loader-operator head injuries has been eliminated.
“Moving to automation at Northparkes was by far the best decision we ever made,” says Northparkes mining operations manager Rob Cunningham.
“What we have today is a very successful solution with a very good partner that has achieved everything and more than we wanted right from the very beginning. It’s been very profitable to the business and it’s been in the best interest of our people as far as health and safety goes.”
Established in 1993, the Northparkes operation is a joint venture between majority owner China Molybdenum (CMOC) and the Sumitomo Groups.
Copper concentrate mined and processed here is taken by truck and rail to Port Kembla on the coast south of Sydney, about 400 kilometres away.
Northparkes initially made a name for itself by becoming the first miner in Australia to use the block cave mining technique.
The approach involves undercutting an ore body and allowing it to progressively collapse under its own weight. Draw bells, (essentially, funnels), are established below the fracturing deposit and feed ore into extraction drives where LHDs convey it to be crushed and taken to the surface for further processing.
Some 80 per cent of Northparkes’ production today comes from its E48 Lift 1 block cave mine, with the remaining 20 per cent coming from the E26 Sub Level Mine.
In 2015, Northparkes achieved a major milestone when its E48 Lift 1 block cave mine became the first mine in the world to achieve full automation, outside of display mines.
Six autonomous Sandvik LH514 loaders (five electric and one diesel) now operate 500 metres below the surface at Northparkes, tramming ore from the draw bells and dropping 11- to 12-tonne loads in the ROM bin for crushing.
Travelling at speeds of up to 21km/h, the LHDs operate autonomously for 80 per cent of their cycle time and rest of the operation cycle is tele operated. Operators working in a screen-filled control room on the surface assume control only when the loader bucket needs filling.
“The Sandvik AutoMine [Fleet] system controls the function of the loader from the draw point to the dump point, tips the bucket and then returns the loader to the draw point,” explains Northparkes’ underground production superintendent, Tim Bray.
“The automation operator then takes control of the loader, fills the bucket and, repeats the cycle.”
Bray explains while the autonomous Sandvik LHDs are slightly more efficient than human operators on a tonnes-per-hour basis, the real productivity gains come from increased utilisation across the 24-hour working day.
Since 2015, Northparkes has moved more than 20 million tonnes of material under automation. In recent years, automation has allowed for production to be ramped up from 5.5 million tonnes annually to 6.5 million tonnes, a rise of 18 per cent.
The switch to automated loaders has also reduced wear and the need for maintenance, helping to push down LHD operating costs by 23 per cent.
Northparkes mobile equipment maintenance superintendent Brad Goodfellow explains, “We’ve seen a reduction in operating costs, a greater level of predictability around fleet life cycle models and the performance of the assets and that basically pushes you into a more of a planned space.”
Rob Cunningham says the next step for Northparkes is fully autonomous operation of its loaders, something it hopes to achieve in 2020 through close collaboration with Sandvik.
“What we want to see in the future is that the machine will come back to the draw point, load itself, pull back and go to the ROM bin. So, everything’s controlled by the system.”
While the benefits of automation to Northparkes are now crystal clear, it took tenacity to remain committed to the concept through various hurdles and partner changes.
Following initial trials in the 1990s that proved the automation was viable, Northparkes trialled various automated loader systems throughout the 2000s. These efforts often involved pairing Sandvik loaders with third-party automation systems.
When planning and construction began on E48 Lift 1 in 2008, Northparkes felt technology was approaching the point where it could commit to full automation of an entire mine site.
In 2011, it signed an agreement to partner with Sandvik in developing automation systems for E48. Together, Northparkes and Sandvik developed the required safety, productivity and automation systems ahead of the commencement of production in 2012, and eventually implemented full loader automation in 2015.
Sandvik support manager for mine automation in Australia Ty Osborne says there were a number of challenges along the way, which Sandvik and Northparkes collaborated to solve.
An issue with repeated cabin damage due to operator error was remedied with enhanced automation software and hardware changes. “We also had an issue where the loader was sliding going into the draw points,” says Osborne.
“Working with Northparkes, we came up with a solution to give more situational awareness to the operator up here on the surface, so they knew when the machine was sliding.”
Meanwhile, fleet data management has also since been introduced via the My Sandvik Digital Service Solutions platform.
The on-going operation of Northparkes’ automation is now supported by team of five and LHDs by a team of 18 Sandvik specialists based on site and working on a roster of five crew at a time.
Sandvik project manager of the service contract at Northparkes, Matt Plummer, says the Sandvik team is continually collaborating with the Northparkes team to find ways of making the operation more efficient.
A recent breakthrough involved pushing out the maintenance interval on the loaders from every 24 hours by fitting a larger grease cannister. “We’ve now taken our service intervals out to 48 hours,” he says.
Rob Cunningham says the greatest strength of Northparkes’ relationship with Sandvik is the shared goal of achieving the best for the operation. “Issues have been always put on the table, managed in open discussion and worked to resolution,” he says.
“And that’s fundamentally how it’s all worked all the way through. While we can have disagreement or we can have different views or ideas, we’ve always worked it out and we’ve always got the best outcome.”
This article also appears in the Jan–Marc edition 2020.