Influence of Na2O Content on Lattice Structures of Iron Oxides during Reduction Process of Fe2O3 Briquetting

In order to fill up the deficiency of the theoretical basis about reduction swelling during Bayan Obo iron concentrate roasting and reduction process, The influence of Na2O content on lattice structures of iron oxides at different reduction stages of Fe2O3 briquetting has been investigated by using the method of 'briquetting-roasting-reduction' and the raw material is ferric oxide(Fe2O3), anhydrous sodium carbonate(Na2CO3) provided by Shanghai Chemical Reagent Company of Chinese Medical Group, The result shows that at roasting stage of Fe2O3 briquetting, Na2O content has no obvious effect on Fe2O3 lattice structure, and Na2CO3 tends to react with Fe2O3, which produces some low melting point ferrate like NaFeO2 and liquid phase; at reduction stage from Fe2O3 to Fe3O4, Fe3O4 has a stable crystal structure and its lattice parameter significantly increases due to the solid solution and liquid phase formed in reduction and roasting processes, respectively, at reduction stage from Fe2O3 to FexO, the XRD diffraction peak of FexO shifts towards the small angle with the increase of Na2O content, resulted from the formation of solid solution; at reduction stage from Fe2O3 to Fe, Na2O has no obvious effect on the lattice parameter and the crystal cell volume of Fe because of its gasification and volatilization at the reduction temperature of 1000 degrees C.