Gold Fields’ Agnew mine fixed a crushing bottleneck with Sandvik, earning industry-wide plaudits for the award-winning upgrade.
Improving production is the name of the game for Gold Fields.
Agnew Gold Mine, located 375km north of Kalgoorlie in WA, boasts a production history that dates to the late 1970s using a combination of underground and surface mining and processes all ore on-site.
However, the mine’s 21-year-old tertiary crushing circuit was becoming unreliable, producing a coarse 8-10mm output that placed significant pressure on the downstream grinding circuit and risked the site’s expansion goals.
Fearing a critical production bottleneck, Gold Fields turned to Sandvik, a multinational mining engineering company that had seen such issues arise worldwide.
“Sandvik really had a solution to every challenge that we threw their way,” Gold Fields principal specialist for studies Tristan Freemantle. “Sandvik was aligned with us from the start.”
A new state-of-the-art Sandvik modular crushing and screening plant was designed with “safety-first” as its core philosophy. A key challenge was installing the new circuit in parallel with the old one to achieve zero downtime. Sandvik’s innovative design helped solve this issue, purpose-building a plant that would optimise material handling and reduce operational hazards.
The partnership has been celebrated, with the Agnew Gold Mine winning the Outstanding Mine Performance Australian Mining Prospect Award.
The plant is now delivering exceptional results. The circuit is approximately 18 per cent more energy-efficient and produces a finer product, with a width of less than 6.5mm. This immediately increased the downstream mill’s maximum throughput from 155 to 170 tonnes per hour, directly meeting the mine’s new expansion needs.
Financially, the upgrade delivered annual savings of at least $1.5 million and an impressive three-year payback period. A large part of this success, Freemantle noted, was the plant’s new automation.
“The old crushing circuit had its own dedicated control room, and the operator relied heavily on visual line-of-sight monitoring,” Freemantle said.
In contrast, the new Sandvik crushers have an “intuitive automation system” that was easy to integrate.
The upgrade also centralised control room duties, so one operator now manages the automatically running crushers from a single control room, supported by extensive CCTV.
This centralisation was a key factor in the annual savings, as it eliminated the need for a permanent second crusher control technician.
“I’m proud to wander around the new crushing circuit, which demonstrates that Gold Fields is really committed to maintaining a safe working environment for our people,” Freemantle said.
Freemantle labelled the finished product at Agnew Gold Mine “outstanding”, and the Prospect Awards agreed, duly recognising it with one of the most prestigious awards of the night.
The Outstanding Mine Performance was proudly sponsored by Bonfiglioli.