Submerged-arc furnaces: Improved electrical conditions for increased energy efficiency and decarbonization (SAPPHIRE)

SAPPHIRE aims to contribute to cleaner and more energy-efficient metal production. We will deepen the understanding of how the electric energy that drives the smelting processes interacts with the process chemistry. This knowledge will be used to improve the stability of smelting furnaces, thereby • reducing the specific energy consumption (kWh/kg alloy produced); and • enabling the transition to bio-based reductants used for decarbonization. We will reach these objectives by • making mathematical models that reliably estimates the electrical resistivity of different raw materials and mixes; • incorporating these estimates into simulation tools capable of modeling the furnace response; and • extracting more information from existing measurements and suggesting new measurements that will improve predictions. SAPPHIRE is led by NORCE. NTNU is a research partner, and our international collaboration includes Reykjavík University and the University of Padova. Our industrial partners Elkem ASA, Eramet Norway AS, Finnfjord AS, and Wacker Chemicals Norway AS support the project through the Norwegian Ferroalloy Producers’ Research Association. Our modeling work runs the full gamut from the development of theoretical frameworks to first-principles simulation models and data-based approaches. Specifically, we will focus on developing fundamental models that explain the overall electrical parameters of the smelting furnaces in terms of the properties of the raw materials. We will also investigate which kinds of measurements are necessary to infer the inner state of the furnaces from external measurements, and how more information can be extracted from existing measurements. Especially important in this regard is the furnace dynamics and the properties of electric arcs. The project will educate one PhD and several MSc students.