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- Long-term energy storage and transportation are essential for a successful transition to renewable energy sources. Metal fuels offer a promising solution, thanks to their high volumetric energy density and stability under ambient conditions, making them strong candidates for CO2-free energy carriers. In the form of micron-sized powder, iron combustion and the reduction of its oxides can deliver and store energy, respectively. The understanding of pure iron powder combustion is gradually improving thanks to a growing number of studies. From an economical and sustainable perspective, the combustion of iron powder containing impurities is interesting, expanding metal sources and limiting refining costs. In the present work, the influence of silicon is studied, with 20-63 µm powder containing92.7wt.%ofironand7wt.%ofsilicon(Fe-7Si). Metalcycloniccombustor(MC2) was used to examine the combustion performance of Fe-7Si powder compared to pure iron in similar conditions. An increase in the preheating temperature to 930°C was required to sustain a partially stable flame of Fe-7Si. Isothermal thermogravimetric analyses (TGAs) of oxidation with air from 540°C to 1200°C show slower oxidation kinetics compared to pure iron. Silicon oxidizes first to SiO2, as predicted by thermodynamics, but hematite and fayalite formation occurs before silicon is fully oxidized. After combustion in the MC2 and oxidation with TGAs, the resulting oxidized powders were analyzed with a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS), as well as an X-ray diffraction (XRD) system. Based on the results, a model of iron-silicon particle ignition was developed, predicting an increase in the ignition temperature from 810°C for pure iron to 947°C for Fe-7Si.