Gaseous Fluorides Formation Mechanism in the Roasting Process of the Fluorite-Bearing Iron Concentrate

Abstract:

The gaseous fluorides formation mechanism in the roasting process of the fluorite-bearing iron concentrate was studied by thermodynamic calculation, differential thermal analysis (DTA) and chemical analysis. The results show that fluorine in the fluorite-bearing iron concentrate begins to escape since 400~500°C, and the emission rate of fluorine significantly increases when the temperature is above 1100°C; in the roasting process of fluorite-bearing iron concentrate, SiO₂, K₂O, Na₂O, MgO, Al₂O₃ in the gangue and water vapor in roasting atmospher react with CaF₂ in fluorite to generate such gaseous fluorides as SiF₄, KF, NaF, MgF₂, AlF₃ and HF; with the increase of roasting temperature, the emission rate of fluorine increases obviously; and the water vapor in roasting atmosphere can improve escaping of fluorine.The results provide a theoretical basis for the improvement of roasting technology to reduce fluorine emission in the roasting or sintering process of Baiyanobo iron concentrate.

• Periodical: Advanced Materials Research (Volumes 690-693)
• Pages: 3498-3505
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.690-693.3498
• Online since: May 2013
• Authors: Yi Ci Wang*, Jian Liang Zhang, Jing Wang, Fang Zhang, Guo Ping Luo
• Keywords: Fluorite-Bearing Iron Concentrate, Formation Mechanism, Gaseous Fluorides, Roasting Process

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