Northern Star’s KCGM recovery and Hemi progress: ramp‑up risks for plant engineers
Reviewed by Joe Ashwell

First reported on Australian Mining
30 Second Briefing
Northern Star Resources is working to stabilise the expanded KCGM processing plant in Western Australia after commissioning issues with mill motor control systems and associated equipment cut October output to 15,300oz from 766,000 tonnes of ore processed. The company is balancing this recovery effort with advancing its Hemi development in the Pilbara, maintaining project schedules while troubleshooting intermittent plant stoppages. For operators, the case underlines the production risk tied to complex drive and control upgrades on large grinding circuits during ramp-up.
Technical Brief
- Intermittent mill motor control faults indicate an electrical/automation failure mode rather than mechanical breakage.
- Likely investigation focus: variable-speed drive logic, protection relays, power quality, and sensor feedback integrity.
- Root-cause work would include event log downloads, transient recording, and staged single-mill restart testing.
- Monitoring upgrades may involve continuous vibration, motor temperature, and drive fault-code trending across the grinding line.
- Remediation options include revised control sequences, derating ramp profiles, or hardware replacement of problematic drive components.
- Safety risk centres on unplanned mill stops/starts, requiring strict lock-out/tag-out and isolation verification.
- Commissioning teams must manage arc-flash, stored-energy and rotating-equipment hazards during repeated fault-recreation tests.
- For similar large grinding circuits, staged integration of new drives with shadow-mode testing reduces ramp-up safety and production risk.
Our Take
The recent completion of the expanded KCGM processing plant tie-in and water infrastructure upgrade in Kalgoorlie, reported in October, means any current recovery work is occurring on a freshly modified circuit, which typically raises commissioning risk but also offers scope to embed new safety controls quickly.
Northern Star Resources’ concurrent investment in 25 units of Sandvik underground equipment for its Western Australian gold operations suggests the group is not pulling back on growth or fleet renewal despite KCGM issues, indicating balance-sheet capacity to manage both remediation and the Hemi build-out.
Within our mining coverage, Northern Star appears frequently in safety- and project-tagged Western Australian gold items, signalling that its operational decisions at KCGM will likely be treated as a reference point for risk management and brownfields expansion across other mature gold hubs in the state.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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