| Citation: |
JIAO Ke-xin, ZHANG Jian-liang, LIU Zheng-jian, WANG Guang-wei. Mineralogical phase and formation mechanism of titanium-bearing protective layers in a blast furnace hearth[J]. Chinese Journal of Engineering, 2019, 41(2): 190-198. DOI: 10.13374/j.issn2095-9389.2019.02.005
|
In theory and practice, TiO2-bearing iron ores are the preferred raw materials for prolonging blast furnace times due to their protection of the refractory lining of the hearth. Currently, however, a lack of detailed understanding of the mineralogical composition, formation mechanism, and ratio of C to N in the Ti(C, N) solid solution leaves the blast furnace operator unable to employ a scientific and effective measure to deal with abnormal hearth erosion. As a result, frequent hearth breakouts might occur, causing great financial loss to steel companies. In the present work, in an attempt to clarify the essence of longevity blast furnaces, investigations were conducted into blast furnace hearth damage together with dissection analyses, to derive the mineralogical composition and microstructure of titanium-bearing protective layers. The results show that the exact chemical composition of the TiCxN1-x which formed in the blast furnace is TiC0.3N0.7. Based on thermodynamic analysis, the standard Gibbs free energy of the formation of Ti(C, N) decreases at first, then increases with increasing TiC content. At different temperatures, the proportion of TiC and TiN in the solid solution is different, i.e., more TiC at higher temperatures but more TiN at lower temperatures. At 1423℃, the TiC0.3N0.7 is formed in the hot-side of the investigated blast furnace hearth, and the thickness of the titanium-bearing protective layer varies with smelting intensity, temperature, and circulation strength of hot metal. This paper classifies the protective layer into various types based on formation mechanism. Finally, a comprehensive regulatory scheme is presented to act as a basis for extending the lifespan of the blast furnace hearth.
| [1] |
Jiao K X, Zhang J L, Liu Z J, et al. Analysis of blast furnace hearth sidewall erosion and protective layer formation. ISIJ Int, 2016, 56(11): 1956 doi: 10.2355/isijinternational.ISIJINT-2016-168
|
| [2] |
Liu Z J, Zhang J L, Yang T J. Low carbon operation of super-large blast furnaces in China. ISIJ Int, 2015, 55(6): 1146 doi: 10.2355/isijinternational.55.1146
|
| [3] |
Jiao K X, Zhang J L, Liu Z J, et al. Properties and application of carbon composite brick for blast furnace hearth. J Min Metall Sect B-Metall, 2015, 51(2): 143 doi: 10.2298/JMMB141107018J
|
| [4] |
Jiao K X, Zhang J L, Liu Z J, et al. Dissection investigation of Ti(C, N) behavior in blast furnace hearth during vanadium titano-magnetite smelting. ISIJ Int, 2017, 57(1): 48 doi: 10.2355/isijinternational.ISIJINT-2016-419
|
| [5] |
Inada T, Kasai A, Nakano K, et al. Dissection investigation of blast furnace hearth-Kokura No. 2 blast furnace (2nd campaign). ISIJ Int, 2009, 49(4): 470 doi: 10.2355/isijinternational.49.470
|
| [6] |
Shinotake A, Nakamura H, Yadoumaru N, et al. Investigation of blast furnace hearth sidewall erosion by core sample analysis and consideration of campaign operation. ISIJ Int, 2003, 43(3): 321 doi: 10.2355/isijinternational.43.321
|
| [7] |
Takatani K, Inada T, Takata K. Mathematical model for transient erosion process of blast furnace hearth. ISIJ Int, 2001, 41(10): 1139 doi: 10.2355/isijinternational.41.1139
|
| [8] |
焦克新, 张建良, 刘征建, 等. 高炉炉缸凝铁层物相分析. 工程科学学报, 2017, 39(6): 838 https://www.cnki.com.cn/Article/CJFDTOTAL-BJKD201706004.htm
Jiao K X, Zhang J L, Liu Z J, et al. Analysis of the phase of the solid iron layer in blast furnace hearth. Chin J Eng, 2017, 39(6): 838 https://www.cnki.com.cn/Article/CJFDTOTAL-BJKD201706004.htm
|
| [9] |
张建良, 焦克新, 刘征建, 等. 长寿高炉炉缸保护层综合调控技术. 钢铁, 2017, 52(12): 1 https://www.cnki.com.cn/Article/CJFDTOTAL-GANT201712001.htm
Zhang J L, Jiao K X, Liu Z J, et al. Comprehensive regulation technology for hearth protective layer of blast furnace longevity. Iron Steel, 2017, 52(12): 1 https://www.cnki.com.cn/Article/CJFDTOTAL-GANT201712001.htm
|
| [10] |
Li Y, Li Y Q, Fruehan R J. Formation of titanium carbonitride from hot metal. ISIJ Int, 2001, 41(12): 1417 doi: 10.2355/isijinternational.41.1417
|
| [11] |
Li Y, Fruehan R J. Thermodynamics of TiCN and TiC in Fe-C sat melts. Metall Mater Trans B, 2001, 32(6): 1203 doi: 10.1007/s11663-001-0108-5
|
| [12] |
白晨光, 裴鹤年, 赵诗金, 等. 碳氮化钛粒度与熔渣粘度关系的研究. 钢铁钒钛, 1995, 16(3): 6 https://www.cnki.com.cn/Article/CJFDTOTAL-GTFT503.001.htm
Bai C G, Pei H N, Zhao S J, et al. An investigation of the relationship between the particle size of titanium carbonitride and the viscosity of blast furnace slag bearing high titania. Iron Steel Van Tit, 1995, 16(3): 6 https://www.cnki.com.cn/Article/CJFDTOTAL-GTFT503.001.htm
|
| [13] |
Zhen Y L, Zhang G H, Chou K C. Viscosity of CaO-MgO-Al2O3-SiO2-TiO2 melts containing TiC particles. Metall Mater Trans B, 2015, 46(1): 155 doi: 10.1007/s11663-014-0169-x
|
| [14] |
Zhen Y L, Zhang G H, Chou K C, et al. Influence of TiN on viscosity of CaO-MgO-Al2O3-SiO2-(TiN) suspension system. Can Metall Q, 2015, 54(3): 340 doi: 10.1179/1879139515Y.0000000004
|
| [15] |
Liu Y X, Zhang J L, Zhang G H, et al. Influence of Ti(C0.3N0.7) on viscosity of blast furnace slags. Ironmak Steelmak, 2017, 44(8): 609 doi: 10.1080/03019233.2016.1223907
|
| [16] |
王喜庆. 钒钛磁铁矿高炉冶炼. 1版. 北京: 冶金工业出版社, 1994
Wang X Q. Blast Furnace Smelting Vanadium Titanium Magnetite. 1st. Beijing: Metallurgical Industry Press, 1994
|
| [17] |
宋建成. 高炉含钛物料护炉技术. 北京: 冶金工业出版社, 1994
Song J C. Titanium Material Protection Technology. Beijing: Metallurgical Industry Press, 1994
|
| [18] |
Wada H, Pehlke R D. Nitrogen solubility and nitride formation in austenitic Fe-Ti alloys. Metall Trans B, 1985, 16(4): 815 doi: 10.1007/BF02667518
|
| [19] |
Ozturk B, Fruehan R J. Thermodynamics of inclusion formation in Fe-Ti-C-N alloys. Metall Trans B, 1990, 21(5): 879 doi: 10.1007/BF02657814
|
| [20] |
Sumito M, Tsuchiya N, Okabe K, et al. Solubility of titanium and carbon in molten Fe-Ti alloys saturated with carbon. Trans Iron Steel Inst Jpn, 1981, 21(6): 414 doi: 10.2355/isijinternational1966.21.414
|
| [21] |
Jonsson S. Assessment of the Fe-Ti-C system calculation of the Fe-Ti-C system and prediction of the solubility limit of Ti(C, N) in liquid Fe. Metall Mater Trans B, 1998, 29(2): 371 doi: 10.1007/s11663-998-0114-y
|
| [22] |
Morizane Y, Ozturk B, Fruehan R J. Thermodynamics of TiOx in blast furnace type slags. Metall Mater Trans B, 1999, 30(1): 29 doi: 10.1007/s11663-999-0004-y
|
| [23] |
Jung I J, Kang S, Jhi S H, et al. A study of the formation of Ti(CN) solid solutions. Acta Mater, 1999, 47(11): 3241 doi: 10.1016/S1359-6454(99)00199-8
|
| [24] |
Jung I J, Kang S. A study of the characteristics of Ti(CN) solid solutions. J Mater Sci, 2000, 35(1): 87 doi: 10.1023/A:1004740516214
|
| [25] |
张家芸. 冶金物理化学. 北京: 冶金工业出版社, 2004
Zhang J Y. Physical Chemistry of Metallurgy. Beijing: Metallurgical Industry Press, 2004
|
| [26] |
郭汉杰. 冶金物理化学教程. 2版. 北京: 冶金工业出版社, 2006
Guo H J. Physical Chemistry of Metallurgy. 2nd Ed. Beijing: Metallurgical Industry Press, 2006
|
| [27] |
Kang S. Stability of nitrogen in titanium carbonitride solid solutions. Met Powder Rep, 1998, 53(5): 37 http://www.sciencedirect.com/science/article/pii/S0026065798850297
|
| [28] |
杜鹤桂. 高炉冶炼钒钛磁铁矿原理. 北京: 科学出版社, 1996
Du H G. Blast Furnace Smelting Principle of Vanadium Titanium Magnetite. Beijing: Science Press, 1996
|
| [29] |
焦克新, 张建良, 左海滨, 等. 高炉炉缸黏滞层物相及形成机理. 东北大学学报(自然科学版), 2014, 35(7): 987 doi: 10.3969/j.issn.1005-3026.2014.07.017
Jiao K X, Zhang J L, Zuo H B, et al. Composition and formation mechanism of viscous layers in blast furnace hearth. J Northeast Univ Nat Sci, 2014, 35(7): 987 doi: 10.3969/j.issn.1005-3026.2014.07.017
|
| [30] |
Jiao K X, Zhang J L, Hou Q F, et al. Analysis of the relationship between productivity and hearth wall temperature of a commercial blast furnace and model prediction. Steel Res Int, 2017, 88(9): 1600475-1 doi: 10.1002/srin.201600475
|
Supported by:
Beijing Renhe Information Technology Co., Ltd.
DownLoad: