Reducing the CO2 Footprint from Simn Production by Optimization of Fluxes

During the production of manganese ferroalloys a large amount of CO2 is emitted. Eramet Norway is committed to reducing its CO2 footprint, and have started several actions in order to reach its long-term climate goals. One of the short-term actions is to optimize the pre-reduction and raw material usage. The usage of carbonated materials contributes to the CO2 emissions both through releasing the bound CO2, and through the released CO2 reacting with solid carbon according to the Boudouard reaction. Removing carbonated fluxes is thus one potential way of reducing the CO2emissions from the furnace. Mass balance calculations were done to check the potential for CO2reduction through removing fluxes, namely dolomite, from the mix blend on a 32 MW SiMn furnace.An industrial trial was run to verify the results from the mass balance. The trial without dolomite lasted for over four months with good operational results. A decrease in CO2 footprint of 8.5% and a reduction in SEC of 5% was achieved when compared to the reference with dolomite. The main drawback of the reduced usage of fluxes is a decrease in Mn recovery.