JV Article: Automation Yields Increased Productivity, Safety at New Afton

An automated loading solution has enabled Canada's only block cave mine to mitigate mud rush hazards and improve productivity - and it paid for itself in less than two months.

Tonnage is tantamount to profitability at New Gold Inc.'s (TSX: NGD, NYSE: NGD) New Afton mine in south-central British Columbia. The mine has moved and milled as much as 22,000 tonnes of ore in a single day and routinely extracts 18,500 tonnes from Canada's only block cave mine.

Like other prolific block caves, New Afton enjoys efficiency with low operating costs. But the mine has also had to conquer one of the biggest block cave challenges: mud rush.

Mitigating mud rush hazards was the major motivation for implementing automated loading at New Afton. As the block cave grew, more and more drawpoints became finely fragmented and wet. By 2016, one in five drawpoints were assessed as high-risk. To ensure operator safety, New Afton stopped manual mucking in those drawpoints and implemented line-of-sight tele-remote loading.

"When 20% of your ore source needs to be remotely mucked, you run the risk that you can't supply your mill with adequate tonnages," says mine manager Peter Prochotsky, who joined New Afton in 2009 as a mining engineer and has seen the operation grow from a development project into Canada's highest-tonnage underground mine. "The line-of-sight systems just weren't keeping up with the growing production demand over the years and we needed a new way of doing things."

New Afton conducted an engineering study in late 2016 to assess the potential value of implementing automated production loading to overcome the production constraint caused by line-of-sight and further improve safety. The mine trialed an AutoMine-equipped Sandvik LH514 for one month in early 2017. The 14-tonne loader ultimately proved too long for some of the cave's tighter turns, but New Afton estimated impressive cycle times and buckets per shift using the smaller LH410.

"To transition from a line-of-sight solution to an automated solution, we calculated a 54-day payback period," Prochotsky says. "If we continued using line-of-sight tele-remotes, that production loss was, essentially over 54 days, the value of a brand new Sandvik LH410. And we obviously made the choice pretty quickly that it was the right way to go."

A remotely-operated LH410 in the New Afton mine. Credit: Sandvik.

New Afton's existing block cave extraction level layout wasn't optimized for automation and to ensure a successful transition a focus on change management was imperative.

Bob Garner, a technical expert with decades of block cave experience, led the operational side and trained operators on the AutoMine system. Electrical instrumentation technician TJ Williams complemented Garner's skills with technical expertise, handling installation of all electrical systems.

"We needed to figure out the infrastructure, figure out the Wi-Fi, where we were going to put antennae points, how far apart they had to be, and then teach the loader its path and dial everything in to get it running efficiently," Garner says.

Sandvik provided initial engineering assistance, starting system implementation in the west cave that Williams was able to replicate himself in the east cave.

"The infrastructure is relatively simple," he says. "Sandvik provided excellent documentation that we followed to a 'T' and I picked things up along the way working with their engineers. The overall process of installation was pretty straightforward."

Within a week of commissioning in late 2017, the first of the mine's two automated Sandvik LH410s was already proving significantly more productive than the tele-remote solution.

Williams says most of the mine's line-of-sight operators were comfortable running AutoMine within five days.

"The Sandvik automated loaders are much more technologically advanced than the competitor loaders featuring aftermarket line-of-sight, but the learning curve wasn't steep," he says. "Everybody picked it up really easy."

For New Afton, AutoMine has proven to be the complete automation solution management assessed it to be.

"If another mine manager came to me and asked me who they should automate with, I think that Sandvik has the best system on the market, and it's really because they have the total package," Prochotsky says. "They've got field service representatives available to come to your site to help train your people, they've got great safety documentation that allows you to make sure there won't be any incidents or accidents underground, and they've got a product that works. It's a pretty simple solution in my mind."

- The preceding Joint-Venture Article is PROMOTED CONTENT sponsored by Sandvik, and presented in cooperation with The Northern Miner. Visit www.home.sandvik for more information.