Turning a Liability into Leverage: The Preheaters That Now Pay Back Weekly
Turning a Liability into Leverage: The Preheaters That Now Pay Back Weekly
How a leading ferroalloy smelter unlocked a value opportunity of more than USD 14.5 million per year through improved control and operator adoption
Anssum partnered with a major ferroalloy smelter to transform two underperforming ore preheaters into reliable, stable assets. By improving the existing control strategy and rebuilding operator confidence, without adding new hardware or instrumentation, the plant increased preheater utilisation, improved energy recovery and furnace throughput, reduced emissions, and significantly reduced manual intervention. The resulting value exceeds USD 14.5 million per year, with the solution paying for itself in less than one week.
Two High-Capacity Preheaters Central to Energy Recovery and Furnace Stability
The facility operates two high-capacity ore preheaters that prepare feed material for electric arc furnaces. The preheaters are important to energy recovery, furnace stability and throughput, but their potential was not being consistently realised.
Underutilised Preheaters Limit Energy Recovery and Furnace Throughput
Low confidence in the preheaters, driven by performance issues believed to be mechanical, resulted in significant underutilisation. Operators frequently reverted to manual control and bypassed the preheaters entirely. As a result, utilisation remained low and the plant was unable to consistently realise the available energy, emissions, and throughput benefits.
Better Control and Operator Adoption Without New Hardware
Anssum unlocked significant value through improved process control, rather than relying on the conventional focus on asset management.
The control objective was reframed around direct ore temperature control to make operation more stable and responsive. Combustion and preheater pressure control logic was redesigned to improve stability and operational consistency. The changes were integrated directly into the existing DCS, avoiding disruption to the operator workflow.
Operators were involved throughout the design and commissioning process. Simulation, hands-on training and iterative tuning using live plant data helped rebuild trust in the system and ensured that the solution made sense in day-to-day plant operation.
Implementation Process
Understanding Preheater Behaviour
- Analysis of how the preheaters were behaving under different operating conditions.
- Assessment of the interaction between preheater performance, combustion, ore temperature and furnace operation.
- Identification of control performance restrictions that were limiting stable and consistent use of the preheaters.
Collaborative Solution Development
- Development of a control approach centred on stable ore temperature and reliable preheater operation.
- Incorporation of operator experience and feedback into the design.
- Alignment of the solution with the way the plant is operated in practice.
Implementation and Refinement
- Integration of the improved control directly into the existing DCS, without additional hardware or changes to the operator environment.
- Progressive testing and refinement using live plant data.
- Stabilisation of the solution under real operating conditions.
Adoption and Sustained Operation
- Simulation and hands-on training to build operator understanding and confidence.
- Transition from frequent manual intervention to confident use of the automated control.
- Transfer of day-to-day ownership to the plant team to support sustained performance.
USD 14.5 Million per Year in Value with Payback in Under One Week
Energy and emissions
- 250 kWh/ton energy recovery achieved.
- Annual value to the business of more than USD 14.5 million p/a.
- 132,000 tons of CO2 emissions avoided annually.
Operational performance
- Preheater utilisation increased to more than 90%.
- 80% reduction in manual overrides and operator burden.
- 65% improvement in ore feed temperature consistency.
- 45% improvement in preheater pressure control stability.
Commercial and strategic impact
- The solution paid for itself in under one week.
- The preheaters were positioned as reliable enablers of furnace uptime, energy efficiency and throughput.
- The improved control foundation supports future condition monitoring and more autonomous operation.
- Operational teams now own and champion the solution, supporting sustained performance.
Key Takeaways
Improved process control unlocks substantially more value than conventional asset-focused improvement.
Existing assets can deliver far more than expected.
Operator confidence is critical to sustained performance.
High value improvement does not have to mean high capital expenditure.
