Combustion of Ferrosilicon–Zircon Mixtures in Nitrogen Gas: Impact of Aluminum Additives

Abstract—Products formed upon combustion of [40 FeSi + 30 FeSiN + 30 ZrSiO₄ (zircon)] + xAl (x = 1.0–10, all figures in wt %) mixtures in nitrogen gas under pressure were characterized by XRD and SEM, with special emphasis on the impact of aluminum additives. Nitrogen content of combustion products and burning velocity were measured as a function of Al content x, nitrogen pressure P and sample diameter ∅. Stable frontal combustion observed at x = 6%, P = 4 MPa, and ∅ = 35 mm was found to yield a product containing β-Si₃N₄/β-Si₃Al₃O₃N₅, ZrO₂, ZrN, Fe_xSi_y, and α-Fe. Our results may turn interesting to those engaged in R & D of facile routes to cost-effective SHS-assisted utilization of industrial wastes and natural raw materials.