Thermodynamic Analysis on Separation Process of Iron and Niobium for Iron Tailings Containing Niobium

Abstract:

Selective Reduction of Cold Bound Pellet – Smelting Separation – Ferroniobium Smelting Technology’ is an effective enrichment and extraction process of Nb from iron tailings of Bayan Obo deposit. Theoretical basis for the thermodynamic feasibility of smelting separation process was provided aiming at the thermodynamic problems in the process by analyzing and calculating through thermodynamic diagram, isothermal equation, and the calculation model of activity for slag system of CaO–SiO₂–FeO–CaF₂–TiO₂–La₂O₃–Nb₂O₅. The results show that the separation of iron and Nb in arc furnace by smelting separation is feasible. In smelting separation process the valence state of Nb in slag is mainly pentavalent and the activity coefficient of Nb₂O₅ is 0.4×10^-5~5.8×10^-5. The distribution ratio of Nb between slag and molten iron decreases with increasing temperature or [%C], whereas increases with increasing basicity (CaO/SiO₂). The temperature should be controlled under 1450°C, the basicity (CaO/SiO₂) should be elevated appropriately, and [%C] should be controlled under 3.6% at the final stage of smelting separation process.

• Periodical: Advanced Materials Research (Volumes 194-196)
• Pages: 2145-2150
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.194-196.2145
• Online since: February 2011
• Authors: Bo Zhang, Jie Qi, Cheng Jun Liu, Mao Fa Jiang
• Keywords: Bayan Obo Deposit, Iron Tailing, Niobium, Smelting Separation, Thermodynamic Analysis

References

[1] G.W. Xiao and G.X. Xing: Science and Technology of Baotou Steel (Group) Corporation, Vol. 29 (2003), pp.9-12 (In Chinese).

[2] M.Q. Cheng: Iron and Steel, Vol. 32 (1997), pp.155-158 (In Chinese).

[3] J. Fang, Z.R. Wang, J.Y. Zhang, Y.G. Zhang, Y.H. Huang, and X.G. Li: Journal of Northeastern University: Natural Science, Vol. 17 (1996), pp.35-40 (In Chinese).

[4] I. Barin, O. Knacke and O. Kubaschewski: Thermochemical properties of inorganic substances (Springer-Verlag, Berlin 1977).

DOI: 10.1007/978-3-662-02293-1

[5] G.K. Sigworth and J.F. Elliott: Metal Science, Vol. 8 (1974) pp.198-310.

[6] S.Y. Li, Y.S. Zhou, H.Y. Du and G.H. Qian: Development and application technique of niobium resource (Metallurgy Industry Press, Beijing 1992). (In Chinese).

[7] N.M. Chuiko: Ferrous Met., Vol. 5 (1959), pp.3-10.

[8] J. Zhang: Proc. 4th International Conference on Molten Slags and Fluxs (The iron and steel Institute of Japan, Sendai 1992).

[9] G. Nürdberg: Schlackenatlas (Verlag Stahleisen M. B. H., Düsseldorf 1981).

[10] C.W. Bale, P. Chartrand and S. A Decterov: Calphad Journal, Vol. 62 (2002), pp.189-228.