Comparison of reduction disintegration characteristics of TiO₂-rich burdens prepared with sintering process and composite agglomeration process

Abstract

To reveal the impact of the composite agglomeration process (CAP) on the reduction disintegration properties of TiO₂-rich ironmaking burden for a blast furnace, the reduction disintegration indices (RDIs), mineral constituents, and microstructure of the products prepared by the CAP and the traditional sintering process (TSP) were investigated. The results showed that, compared to the sinter with a basicity of 2.0 prepared by the TSP, the RDI_+6.3 and the RDI_+3.15 of the CAP product with the same basicity increased by 28.2wt% and 13.7wt%, respectively, whereas the RDI_−0.5 decreased by 2.7wt%. The analysis of the mineral constituents and microstructure of the products indicated that the decreasing titanohematite content decreased the volume expansion during reduction. Meanwhile, the decreasing perovskite content decreased its detrimental effect on the reduction disintegration properties. In addition, the higher silicoferrite of calcium and aluminum (SFCA) content improved the strength of the CAP product. Together, these factors result in an improvement of the RDI of the CAP products. In addition, compared to the sinter, the reduced CAP products clearly contained fewer cracks, which also led to mitigation of reduction disintegration.

Keywords

ore reduction / titanomagnetite / agglomeration / sintering

References

[1] Loo C.E., Bristow N.J. Mechanism of low-temperature reduction degradation of iron ore sinters. Trans. Inst. Min. Metall. Sec. C, 1994, 103, 128.

[2] Gao Y.W., Li J.S., Liu C.S., Tang H.Y. Low-temperature reduction degradation characteristic of different iron ores. China Metall., 2013, 23(10): 1.

[3] Wu S.L., Liu X.Q., Zhou Q., Xu J., Liu C.S. Low temperature reduction degradation characteristics of sinter, pellet and lump ore. J. Iron Steel Res. Int., 2011, 18(8): 20.

[4] Fu J.Y., Jiang T., Zhu D.Q. Principles of Sintering and Pelletizing, 2006, Changsha, Central South University Press, 212.

[5] Dawson P.R. Recent developments in iron ore sintering. Ironmaking Steelmaking, 1993, 20(2): 135.

[6] Wu C.B., Cheng X.L., Gao Y., Yang C., Yin G.L. Effect of basicity on reduction disintegration property of low-silicon sinter in Nan Gang. Sintering Pelletizing, 2008, 33(6): 14.

[7] Yang H.M., Qiu G.Z., Tang A.D. Effect of CaCl2 on RDI of sinter. J. Cent. South Univ. Technol., 1998, 29(3): 229.

[8] Jiang D.J., He M.G., Gan Q., He Q. Effect of FeO on properties of high-basicity sinter. China Metall., 2008, 18(11): 14.

[9] Taylor P.R., Vidal E.E., Shuey S.A., Gomez J.C. Extractive metallurgy of vanadium-containing titaniferous magnetite ores: a review. Miner. Metall. Process., 2006, 23(2): 80.

[10] Peng Z.W., Hwang J.Y. Microwave-assisted metallurgy. Int. Mater. Rev., 2015, 60(1): 30.

[11] Yu Z.W., Li G.H., Jiang T., Zhang Y.B., Peng Z.W. Effect of basicity on titanomagnetite concentrate sintering. ISIJ Int., 2015, 55(4): 907.

[12] Sun Y.Q., Lv Q., Li F.M. Research on high-basicity vanadium-bearing titanomagnetite sinter properties. Res. Iron Steel, 2010, 6, 10.

[13] Bristow N.J., Loo C.E. Sintering properties of iron ore mixes containing titanium. ISIJ Int., 1992, 32(7): 819.

[14] Yang H.M., Qiu G.Z. Influencing mechanism of TiO2 on reduction disintegration index of sinter. Multipurpose Utiliz. Miner. Resour., 1998, 1, 12.

[15] Liu R., Liu C.Q., Liu X.J., Qie Y.N., Lv Q. Effect of perovskite content on sintering properties of vanadium-bearing titanomagnetite. Chin. J. Process Eng., 2015, 15(1): 62.

[16] Du H.G. Principles of Vanadium-bearing Titanomagnetite Smelting in Blast Furnace, 1996, Beijing, Science Press, 137.

[17] Wang R.Z., Sun Y.Q., Lv Q., Wu W.N., Feng S. Research on low-chloride inhibitor of reduction disintegration index of vanadium-bearing titanomagnetite sinter. J. Hebei Unit. Univ. Nat. Sci., 2013, 35(2): 4.

[18] Guo H.L., Hu B.S., Gui Y.L. Behavior on blast furnace smelting process of chlorine in coal. China Metall., 2010, 20(11): 12.

[19] Zheng H.M. Research on Appropriate FeO Content for Sinter of Chongqing Iron & Steel Company, 2008, Chongqing, Chongqing University, 64.

[20] Jiang T., Li G.H., Wang H.T., Zhang K.C., Zhang Y.B. Composite agglomeration process (CAP) for preparing blast furnace burden. Ironmaking Steelmaking, 2010, 37(1): 1.

[21] Jiang T., Yu Z.W., Peng Z.W., Rao M.J., Zhang Y.B., Li G.H. Preparation of BF burden from titanomagnetite concentrate by composite agglomeration process (CAP). ISIJ Int., 2015, 55(8): 1599.