Delivering plantwide control for Arrium’s Iron Knob mine

Arrium faced a complex greenfield challenge at its Iron Knob hematite iron ore mine in South Australia: design, install, and commission a full crushing and screening plant capable of processing millions of tonnes of ore annually — while keeping downtime to an absolute minimum. In metals and mining, extended commissioning windows translate directly to lost production and deferred revenue. A conventional fixed-plant approach at this scale would have required heavy civil infrastructure and a lengthy build program, driving capital costs upward and exposing the operation to prolonged ramp-up risk. Arrium needed a smarter architecture that could deliver plantwide control and safety without the footprint or cost of a traditional installation.

Rockwell Automation engineered a modular, mobile plant architecture that fundamentally changed the economics of the project. At the core was an Allen-Bradley ControlLogix programmable automation controller paired with GuardLogix safety controllers, providing integrated process control and functional safety across the entire plant from a single platform. Seventy-five Allen-Bradley PowerFlex variable-frequency drives were deployed across feeders, conveyors, and crushers, enabling precise speed and torque control throughout the material handling circuit. FactoryTalk View SE served as the plantwide SCADA and HMI layer, giving operators unified visibility into all equipment states and process conditions. By mounting this control architecture on mobile equipment rather than fixed civil structures, the team dramatically compressed installation timelines and eliminated the need for extensive on-site construction.

The mobile and modular approach delivered a 50% reduction in plant capital costs — approximately $40 million in savings compared to a conventional fixed installation. Beyond the headline capital saving, the plant achieved strong operational performance:

• ~5 million tonnes of ore processed per annum, meeting Arrium's production targets
• Minimal unplanned downtime, enabled by the high availability of the ControlLogix/GuardLogix architecture
• Rapid commissioning relative to a fixed-plant equivalent, accelerating time to first ore
• Integrated safety and process control on a single platform reduced engineering complexity and ongoing maintenance burden

• Mobile and modular plant design can halve capital expenditure in greenfield mining projects — evaluate this architecture before committing to fixed civil infrastructure.
• Integrating safety and process control on a single platform (ControlLogix + GuardLogix) reduces system complexity and simplifies long-term maintenance and compliance.
• Plantwide drive standardization (75 PowerFlex drives across all equipment classes) lowers spare parts inventory and operator training requirements at remote sites.
• SCADA visibility from day one is critical in high-throughput ore processing; don't treat HMI as a post-commissioning addition.
• Mining operations should assess whether production volume targets can be met with high-availability automation rather than equipment redundancy alone.