Underground automation leader reaps benefits

AFTER taking its first steps towards underground loader automation in the 1990s, Australian copper mine Northparkes has become a showcase for the benefits automation can offer.
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Operators in Northparkes' tele-remote facility.

In 1998 the operation began cooperating in early trials investigating the viability of semi-automated load, haul and dump machines.

The mine, run by a joint venture between China Molybdenum Company and Sumitomo Group, switched to a semi-automated Sandvik LHD fleet in its E48 block cave mine in 2015 and has boosted output there by nearly 20%.

Daily loader productivity is up 24%, costs per tonne are down 23%, and the problem of loader operator head injuries has been eliminated.

While human the LHDs are only operating semi-autonomously at the moment, Northparkes and Sandvik hope to convert them to full autonomous operation this year.

Northparkes originally made a name for itself by becoming the first miner in Australia to use the block cave technique.

These days 80% of the mine's production comes from its E48 Lift 1 block cave mine with the remaining 20% coming from the E26 sub level mine.

Northparkes mining operations manager Rob Cunningham said moving to automation at the mine was the best decision the joint venture ever made.

"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," he said.

"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."

The Sandvik LHD fleet mining E48 is made up of five electric LH514 loaders and one diesel LH514 loader.

Those machines tram ore from the draw points 500m below the surface and drop 11t-12t loads in the run-of-mine bin for crushing.

The LHDs operate autonomously 80% of the time and under tele-remote operation for the remaining 20%.

Operators working in a screen-filled control room on the surface assume control only when the bucket needs filling.

Northparkes underground production superintendent Tim Bray said the Sandvik Automine fleet system controlled the function of the loader from the draw point to the dump point, tipped the bucket and returned the loader to the draw point

"The automation operator then takes control of the loader, fills the bucket and repeats the cycle," he said.

Bray said while the semi-autonomous Sandvik LHDs were slightly more efficient than human operators on a tonne per hour basis, the real productivity gains came from increased utilisation across the 24-hour working day.

Since 2015 Northparkes has moved more than 20 million tonnes of material under semi-autonomous operation.

In recent years this has allowed for production to be ramped up from 5.5 million tonnes per annum to 6.5Mtpa - an 18% rise.

The switch to the semi-autonomous loaders has also reduced wear and the need for maintenance, helping push LHD operating costs down 23%.

Northparkes mobile equipment maintenance superintendent Brad Goodfellow said his team had seen a reduction in operating costs, and a greater level of predictability around fleet life cycle models and the performance of the assets.

Cunningham said Northparkes hoped to take the step to fully autonomous operation of its loaders this year 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," he said.

While the benefits of automation at Northparkes are clear, it took tenacity to remain committed to the concept through various hurdles and partner changes.

After initial trials in the 1990s proved the automation was viable, Northparkes tried various automated loader systems throughout the 2000s.

Those efforts often involved pairing Sandvik loaders with third party automation systems.

When planning and construction began on E48 Lift 1 in 2008 Northparkes' management felt the 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 to develop automation systems for E48.

Together Northparkes and Sandvik developed the required safety, productivity and automation systems ahead of the start of production at E48 in 2012.

The full semi-autonomous loader operation was implemented in 2015.

Sandvik support manager for mine automation in Australia Ty Osborne said there were a number of challenges along the way, which Sandvik and Northparkes collaborated on to solve.

An issue with repeated cabin damage due to operator error was remedied with improved automation software and hardware changes.

"We also had an issue where the loader was sliding going into drawpoints," he said.

"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."

Fleet data management has also been introduced at Northparkes through the My Sandvik Digital Service Solutions platform.

The ongoing operation of Northparkes' autonomous systems is supported by a team of five and the 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 Northparkes service contract Matt Plummer said the Sandvik team was continually collaborating with the Northparkes team to find ways to operate more efficiently.

A recent improvement was increasing the loaders' maintenance interval from 24 hours to 48 hours by fitting a larger grease canister.

Cunningham said issues had always been put on the table, managed in open discussion and worked to resolution.

"And that's fundamentally how it's all worked all the way through," he said.

"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."

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