Design and operation of smelting furnaces have been gradually improved through industrial experience, research, modern process control, new and/or improved measurements, etc. Nevertheless, due to all complexities in the processes, several process variations are not properly understood. The furnace centre is hot, above 2000 °C for some processes, and reliable measurements of the inner conditions are extremely difficult.
The processes are energy intensive. The power is normally supplied by high, three-phase, electric currents, often more than 100 000 A. The current paths depend on electrical resistivity of the raw materials, partly reacted materials, and the metal that has been produced. Hence, there is a strong interaction between electrical current paths, temperature distribution, and chemical reactions.
The SAFECI project has made important strides in understanding how electricity behaves inside smelting furnaces used to produce ferroalloys—materials essential for steelmaking and other industries. This new knowledge will help make Norwegian ferroalloy production more energy-efficient and environmentally friendly in the years ahead.
By the end of the project, two industrial partners have implemented new types of electrical measurements. These innovations will improve how furnaces are controlled, leading to better performance and reduced energy use.
SAFECI also contributed to building expertise in the field: 10 researchers and professionals received training, and the project led to 21 scientific publications and one successful follow-up research proposal.
The project was led by NORCE, with NTNU as a research partner, and included international collaboration with the University of Padua. The industrial partners were Elkem ASA, Eramet Norway AS, Finnfjord AS, and Wacker Chemicals Norway AS.
The project has combined physics-based modeling with data-driven approaches and novel measurements:
Physics-based finite-element models from the ElMet project (project number 247791) have been continuously updated and used to simulate issues such as large electrode movements, unbalanced electrical conditions, induction and voltage measurements, and magnetic measurements. Computationally lightweight models (metamodels) have been derived from the finite-element models and are available online at https://safeci.web.norce.cloud.... Metamodels are useful for operator training and for studying controller performance.
The project also explored new ways to predict electrical resistance in electrodes and started developing a framework for combining live process data with metamodel predictions. This work continues in the project SAPPHIRE (project number 358034).
SAFECI reviewed the electrical measurements currently used in industry. Additional electrical measurements have been proposed, tested, and are scheduled for industrial implementation. The project also used circuit models to explore how energy can be saved by making changes to the furnace power supply.
The project also carried out detailed laboratory measurements of the bulk resistivity of raw materials used in ferroalloy production. These measurements were performed across a range of temperatures and included both pure materials and partially transformed mixtures. The resulting dataset provides a valuable reference for understanding how electrical properties change during the smelting process. This knowledge is essential for improving the furnace models and will serve as a foundation for future research (SAPPHIRE, project number 358034) and industrial applications.
