GR Engineering Services says it has executed an engineering, procurement and construction (EPC) contract with Northern Star Resources in relation to the Thunderbox 6 Mt/y expansion project in Western Australia.

Located 45 km south of Leinster, the Thunderbox operations currently have a 3 Mt/y processing capacity. The asset was owned by Saracen Mineral Holdings prior to a merger with Northern Star.

The works will involve the design, engineering, procurement, construction and commissioning of the project, with the contract sum amounting to A$101 million ($74.3 million) and work is expected to start immediately.

GR Engineering has carried out several projects on the Thunderbox operations, including EPC work on the Thunderbox paste plant work, which has seen a new 150 cu.m paste backfill plant built.

Commenting on the recent award, Geoff Jones, GR Engineering Managing Director, said: “GR Engineering is excited to continue working with Northern Star, one of the world’s leading gold producers, to safely deliver the Thunderbox Expansion project. We have worked with the Northern Star team over many years and see this award as a strong endorsement of our proven EPC delivery capability.”

On award of Northern Star’s largest infrastructure project to date, Northern Star’s General Manager Processing, Simon Tyrrell, said: “The Thunderbox expansion increases the operation’s hard-rock processing capacity to 6 Mt/y from the current 3 Mt/y, and decreases processing costs as outlined in the 2021 Investor Day Presentation. Northern Star is pleased to be working with GR Engineering again, a local company with vast project delivery experience in the Australian mining industry.”

In this same presentation, the company said the processing capacity boost would involve the addition of a new 18 MW mill and classification circuit; new leach tanks, elution and gold room upgrades; and new tailing thickener and tailings pumping. The plant would be designed for 100% fresh ore, NSR said.