Effect of MgO content in sinter on the softening–melting behavior of mixed burden made from chromium-bearing vanadium–titanium magnetite

Abstract

The effect of sinter with different MgO contents on the softening–melting behavior of mixed burden made from chromium- bearing vanadium–titanium magnetite was investigated. The results show that with increasing MgO content in the sinter, the softening interval and melting interval increased and the location of the cohesive zone shifted downward slightly and became moderately thicker. The softening–melting characteristic value was less pronounced when the MgO content in the sinter was 2.98wt%–3.40wt%. Increasing MgO content in the sinter reduced the content and recovery of V and Cr in the dripped iron. In addition, greater MgO contents in the sinter resulted in the generation of greater amounts of high-melting-point components, which adversely affected the permeability of the mixed burden. When the softening–melting behavior of the mixed burden and the recovery of valuable elements were taken into account, proper MgO contents in the sinter and slag ranged from 2.98wt% to 3.40wt% and from 11.46wt% to 12.72wt%, respectively, for the smelting of burden made from chromium-bearing vanadium–titanium magnetite in a blast furnace.

Keywords

ironmaking / magnetite / magnesia / softening / melting behavior / sinter / blast furnace practice

References

[1] Du H.G. Principle of Blast Furnace Smelting Vanadium Titanium Magnetite, 1996, Beijing, Science Press, 1.

[2] Jena B.C., Dresler W., Reilly I.G. Extraction of titanium, vanadium and iron from titanomagnetite deposits at pipestone lake. Manitoba, Canada, Miner. Eng., 1995, 8(1-2): 159.

[3] Chen S.Y., Chu M.S. Metalizing reduction and magnetic separation of vanadium titano-magnetite based on hot briquetting. Int. J. Miner. Metall. Mater., 2014, 21(3): 225.

[4] Hu T., Lv X.W., Bai C.G., Qiu G.B. Isothermal reduction of titanomagnetite concentrates containing coal. Int. J. Miner. Metall. Mater., 2014, 21(2): 131.

[5] Monakhov I.N., Khromov S.V., Chernousov P.I., Yusfin Y.S. The flow of vanadium-bearing materials in industry. Metallurgist, 2004, 48(7): 381.

[6] Samanta S., Goswami M.C., Baidya T.K., Mukherjee S., Dey R. Mineralogy and carbothermal reduction behaviour of vanadium-bearing titaniferous magnetite ore in Eastern India. Int. J. Miner. Metall. Mater., 2013, 20(10): 917.

[7] Chu M.S. Raw Materials. Fuel and Auxiliary Materials for Iron and Steel Metallurgy, Metallurgical Industry Press, Beijing, 2010 57.

[8] Shiau J.S., Liu S.H., Ho C.K. Effect of magnesium and aluminum oxides on fluidity of final blast furnace slag and its application. Mater. Trans. JIM, 2012, 53(8): 1449.

[9] Papanastassiou D., Nicolaou P., Send A. Effect of Al2O₃ and MgO contents on the properties of the blast furnace slag. Stahl Eisen, 2000, 120(7): 59.

[10] Yang X.M., Jiao J.S., Ding R.C., Shi C.B., Guo H.J. A thermodynamic model for calculating sulphur distribution ratio between CaO–SiO₂–MgO–Al₂O₃ ironmaking slags and carbon saturated hot metal based on the ion and molecule coexistence theory. ISIJ Int., 2009, 49(12): 1828.

[11] Yadav U.S., Pandey B.D., Das B.K., Jena D.N. Influence of magnesia on sintering characteristics of iron ore. Ironmaking Steelmaking, 2002, 29(2): 91.

[12] Gunther S. Experiment and study on effects of different basicity and contents of MgO and SiO₂ in sinter. ISIJ Int., 1998, 38(7): 457.

[13] Shen F.M., Jiang X., Wu G.S., Wei G., Li X.G., Shen Y.S. Proper MgO addition in blast furnace operation. ISIJ Int., 2006, 46(1): 65.

[14] Liu X.L., Wu S.L., Huang W., Zhang K.F., Du K.P. Influence of high temperature interaction between sinter and lump ores on the formation behavior of primary-slags in blast furnace. ISIJ Int., 2014, 54(9): 2089.

[15] Kaushik P., Fruehan R.J. Mixed burden softening and melting phenomena in blast furnace operation: Part 3. Mechanism of burden interaction and melt exudation phenomenon. Ironmaking Steelmaking, 2007, 34(1): 10.

[16] Tang J., Zhang Y., Chu M.S., Xue X.X. Preparation of oxidized pellets with high chromium vanadium–titanium magnetite. J. Northeast. Univ. Nat. Sci., 2013, 34(4): 545.

[17] Tang J., Zhang Y., Chu M.S., Xue X.X. Effect of the increasing percent of high chromium vanadium-titanium magnetite on quality of oxidized pellets. J. Northeast. Univ. Nat. Sci., 2013, 34(7): 956.

[18] Tang J., Chu M.S., Li F., Tang Y.T., Liu Z.G., Xue X.X. Reduction mechanism of high-chromium vanadium–titanium magnetite pellets by H2–CO–CO₂ gas mixtures. Int. J. Miner. Metall. Mater., 2015, 22(6): 562.

[19] Zhou M., Yang S.T., Jiang T., Xue X.X. Influence of MgO in form of magnesite on properties and mineralogy of high chromium. vanadium, titanium magnetite sinters, Ironmaking Steelmaking, 2015, 42(3): 217.

[20] Tang J., Chu M.S., Xue X.X. Optimized use of MgO flux in the agglomeration of high-chromium vanadium–titanium magnetite. Int. J. Miner. Metall. Mater., 2015, 22(4): 371.

[21] Wu S.L., Tuo B.Y., Zhang L.H., Du K.P., Sun Y. New evaluation methods discussion of softening-melting and dropping characteristic of BF iron bearing burden. Steel Res. Int., 2014, 85(2): 233.

[22] Nandy B., Chandra S., Bhattacharjee D., Ghosh D. Assessment of blast furnace behaviour through softening-melting test. Ironmaking Steelmaking, 2006, 33(2): 111.

[23] Chu M.S., Liu Z.G., Wang Z.C., Yagi J.I. Fundamental study on carbon composite iron ore hot briquette used as blast furnace burden. Steel Res. Int., 2011, 82(5): 521.

[24] Chu M.S., Liu Z.G., Wang Z.C., Zhao K., Guo T.L. Experimental study on softening-dripping behavior of BF burdens with charging carbon composite iron ore hot briquette. Iron Steel, 2011, 46(11): 16.

[25] Chu M.S., Liu Z.G., Wang Z.C., Fu L. Effects of carbon ratio on softening-dripping behavior of carbon composite iron ore hot briquette. J. Northeast. Univ. Nat. Sci., 2010, 31(3): 394.

[26] Kaushik P., Fruehan R.J. Mixed burden softening and melting phenomena in blast furnace operation: Part 1. X-ray observation of ferrous burden. Ironmaking Steelmaking, 2006, 33(6): 507.

[27] Yang Z.X. The softening-melting process of iron ore at high temperature were studied with X-ray method. Sintering Pelletizing, 1985, 3, 1.